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| <li>Summary: </li> |
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| <div class="sub-title"><span class="package-label-in-type">Package</span> <a href="package-summary.html">org.apache.kafka.streams.kstream</a></div> |
| <h1 title="Interface KStream" class="title">Interface KStream<K,<wbr>V></h1> |
| </div> |
| <section class="class-description" id="class-description"> |
| <dl class="notes"> |
| <dt>Type Parameters:</dt> |
| <dd><code>K</code> - Type of keys</dd> |
| <dd><code>V</code> - Type of values</dd> |
| </dl> |
| <hr> |
| <div class="type-signature"><span class="modifiers">public interface </span><span class="element-name type-name-label">KStream<K,<wbr>V></span></div> |
| <div class="block"><code>KStream</code> is an abstraction of a <i>record stream</i> of <a href="../KeyValue.html" title="class in org.apache.kafka.streams"><code>KeyValue</code></a> pairs, i.e., each record is an |
| independent entity/event in the real world. |
| For example a user X might buy two items I1 and I2, and thus there might be two records <code><K:I1>, <K:I2></code> |
| in the stream. |
| <p> |
| A <code>KStream</code> is either <a href="../StreamsBuilder.html#stream(java.lang.String)"><code>defined from one or multiple Kafka topics</code></a> that |
| are consumed message by message or the result of a <code>KStream</code> transformation. |
| A <a href="KTable.html" title="interface in org.apache.kafka.streams.kstream"><code>KTable</code></a> can also be <a href="KTable.html#toStream()"><code>converted</code></a> into a <code>KStream</code>. |
| <p> |
| A <code>KStream</code> can be transformed record by record, joined with another <code>KStream</code>, <a href="KTable.html" title="interface in org.apache.kafka.streams.kstream"><code>KTable</code></a>, |
| <a href="GlobalKTable.html" title="interface in org.apache.kafka.streams.kstream"><code>GlobalKTable</code></a>, or can be aggregated into a <a href="KTable.html" title="interface in org.apache.kafka.streams.kstream"><code>KTable</code></a>. |
| Kafka Streams DSL can be mixed-and-matched with Processor API (PAPI) (c.f. <a href="../Topology.html" title="class in org.apache.kafka.streams"><code>Topology</code></a>) via |
| <a href="#process(org.apache.kafka.streams.processor.api.ProcessorSupplier,java.lang.String...)"><code>process(...)</code></a>, |
| <a href="#transform(org.apache.kafka.streams.kstream.TransformerSupplier,java.lang.String...)"><code>transform(...)</code></a>, and |
| <a href="#transformValues(org.apache.kafka.streams.kstream.ValueTransformerSupplier,java.lang.String...)"><code>transformValues(...)</code></a>.</div> |
| <dl class="notes"> |
| <dt>See Also:</dt> |
| <dd> |
| <ul class="see-list"> |
| <li><a href="KTable.html" title="interface in org.apache.kafka.streams.kstream"><code>KTable</code></a></li> |
| <li><a href="KGroupedStream.html" title="interface in org.apache.kafka.streams.kstream"><code>KGroupedStream</code></a></li> |
| <li><a href="../StreamsBuilder.html#stream(java.lang.String)"><code>StreamsBuilder.stream(String)</code></a></li> |
| </ul> |
| </dd> |
| </dl> |
| </section> |
| <section class="summary"> |
| <ul class="summary-list"> |
| <!-- ========== METHOD SUMMARY =========== --> |
| <li> |
| <section class="method-summary" id="method-summary"> |
| <h2>Method Summary</h2> |
| <div id="method-summary-table"> |
| <div class="table-tabs" role="tablist" aria-orientation="horizontal"><button id="method-summary-table-tab0" role="tab" aria-selected="true" aria-controls="method-summary-table.tabpanel" tabindex="0" onkeydown="switchTab(event)" onclick="show('method-summary-table', 'method-summary-table', 3)" class="active-table-tab">All Methods</button><button id="method-summary-table-tab2" role="tab" aria-selected="false" aria-controls="method-summary-table.tabpanel" tabindex="-1" onkeydown="switchTab(event)" onclick="show('method-summary-table', 'method-summary-table-tab2', 3)" class="table-tab">Instance Methods</button><button id="method-summary-table-tab3" role="tab" aria-selected="false" aria-controls="method-summary-table.tabpanel" tabindex="-1" onkeydown="switchTab(event)" onclick="show('method-summary-table', 'method-summary-table-tab3', 3)" class="table-tab">Abstract Methods</button><button id="method-summary-table-tab6" role="tab" aria-selected="false" aria-controls="method-summary-table.tabpanel" tabindex="-1" onkeydown="switchTab(event)" onclick="show('method-summary-table', 'method-summary-table-tab6', 3)" class="table-tab">Deprecated Methods</button></div> |
| <div id="method-summary-table.tabpanel" role="tabpanel"> |
| <div class="summary-table three-column-summary" aria-labelledby="method-summary-table-tab0"> |
| <div class="table-header col-first">Modifier and Type</div> |
| <div class="table-header col-second">Method</div> |
| <div class="table-header col-last">Description</div> |
| <div class="col-first even-row-color method-summary-table method-summary-table-tab2 method-summary-table-tab3 method-summary-table-tab6"><code><a href="KStream.html" title="interface in org.apache.kafka.streams.kstream">KStream</a><<a href="KStream.html" title="type parameter in KStream">K</a>,<wbr><a href="KStream.html" title="type parameter in KStream">V</a>>[]</code></div> |
| <div class="col-second even-row-color method-summary-table method-summary-table-tab2 method-summary-table-tab3 method-summary-table-tab6"><code><a href="#branch(org.apache.kafka.streams.kstream.Named,org.apache.kafka.streams.kstream.Predicate...)" class="member-name-link">branch</a><wbr>(<a href="Named.html" title="class in org.apache.kafka.streams.kstream">Named</a> named, |
| <a href="Predicate.html" title="interface in org.apache.kafka.streams.kstream">Predicate</a><? super <a href="KStream.html" title="type parameter in KStream">K</a>,<wbr>? super <a href="KStream.html" title="type parameter in KStream">V</a>>... predicates)</code></div> |
| <div class="col-last even-row-color method-summary-table method-summary-table-tab2 method-summary-table-tab3 method-summary-table-tab6"> |
| <div class="block"><span class="deprecated-label">Deprecated.</span> |
| <div class="deprecation-comment">since 2.8.</div> |
| </div> |
| </div> |
| <div class="col-first odd-row-color method-summary-table method-summary-table-tab2 method-summary-table-tab3 method-summary-table-tab6"><code><a href="KStream.html" title="interface in org.apache.kafka.streams.kstream">KStream</a><<a href="KStream.html" title="type parameter in KStream">K</a>,<wbr><a href="KStream.html" title="type parameter in KStream">V</a>>[]</code></div> |
| <div class="col-second odd-row-color method-summary-table method-summary-table-tab2 method-summary-table-tab3 method-summary-table-tab6"><code><a href="#branch(org.apache.kafka.streams.kstream.Predicate...)" class="member-name-link">branch</a><wbr>(<a href="Predicate.html" title="interface in org.apache.kafka.streams.kstream">Predicate</a><? super <a href="KStream.html" title="type parameter in KStream">K</a>,<wbr>? super <a href="KStream.html" title="type parameter in KStream">V</a>>... predicates)</code></div> |
| <div class="col-last odd-row-color method-summary-table method-summary-table-tab2 method-summary-table-tab3 method-summary-table-tab6"> |
| <div class="block"><span class="deprecated-label">Deprecated.</span> |
| <div class="deprecation-comment">since 2.8.</div> |
| </div> |
| </div> |
| <div class="col-first even-row-color method-summary-table method-summary-table-tab2 method-summary-table-tab3"><code><a href="KStream.html" title="interface in org.apache.kafka.streams.kstream">KStream</a><<a href="KStream.html" title="type parameter in KStream">K</a>,<wbr><a href="KStream.html" title="type parameter in KStream">V</a>></code></div> |
| <div class="col-second even-row-color method-summary-table method-summary-table-tab2 method-summary-table-tab3"><code><a href="#filter(org.apache.kafka.streams.kstream.Predicate)" class="member-name-link">filter</a><wbr>(<a href="Predicate.html" title="interface in org.apache.kafka.streams.kstream">Predicate</a><? super <a href="KStream.html" title="type parameter in KStream">K</a>,<wbr>? super <a href="KStream.html" title="type parameter in KStream">V</a>> predicate)</code></div> |
| <div class="col-last even-row-color method-summary-table method-summary-table-tab2 method-summary-table-tab3"> |
| <div class="block">Create a new <code>KStream</code> that consists of all records of this stream which satisfy the given predicate.</div> |
| </div> |
| <div class="col-first odd-row-color method-summary-table method-summary-table-tab2 method-summary-table-tab3"><code><a href="KStream.html" title="interface in org.apache.kafka.streams.kstream">KStream</a><<a href="KStream.html" title="type parameter in KStream">K</a>,<wbr><a href="KStream.html" title="type parameter in KStream">V</a>></code></div> |
| <div class="col-second odd-row-color method-summary-table method-summary-table-tab2 method-summary-table-tab3"><code><a href="#filter(org.apache.kafka.streams.kstream.Predicate,org.apache.kafka.streams.kstream.Named)" class="member-name-link">filter</a><wbr>(<a href="Predicate.html" title="interface in org.apache.kafka.streams.kstream">Predicate</a><? super <a href="KStream.html" title="type parameter in KStream">K</a>,<wbr>? super <a href="KStream.html" title="type parameter in KStream">V</a>> predicate, |
| <a href="Named.html" title="class in org.apache.kafka.streams.kstream">Named</a> named)</code></div> |
| <div class="col-last odd-row-color method-summary-table method-summary-table-tab2 method-summary-table-tab3"> |
| <div class="block">Create a new <code>KStream</code> that consists of all records of this stream which satisfy the given predicate.</div> |
| </div> |
| <div class="col-first even-row-color method-summary-table method-summary-table-tab2 method-summary-table-tab3"><code><a href="KStream.html" title="interface in org.apache.kafka.streams.kstream">KStream</a><<a href="KStream.html" title="type parameter in KStream">K</a>,<wbr><a href="KStream.html" title="type parameter in KStream">V</a>></code></div> |
| <div class="col-second even-row-color method-summary-table method-summary-table-tab2 method-summary-table-tab3"><code><a href="#filterNot(org.apache.kafka.streams.kstream.Predicate)" class="member-name-link">filterNot</a><wbr>(<a href="Predicate.html" title="interface in org.apache.kafka.streams.kstream">Predicate</a><? super <a href="KStream.html" title="type parameter in KStream">K</a>,<wbr>? super <a href="KStream.html" title="type parameter in KStream">V</a>> predicate)</code></div> |
| <div class="col-last even-row-color method-summary-table method-summary-table-tab2 method-summary-table-tab3"> |
| <div class="block">Create a new <code>KStream</code> that consists all records of this stream which do <em>not</em> satisfy the given |
| predicate.</div> |
| </div> |
| <div class="col-first odd-row-color method-summary-table method-summary-table-tab2 method-summary-table-tab3"><code><a href="KStream.html" title="interface in org.apache.kafka.streams.kstream">KStream</a><<a href="KStream.html" title="type parameter in KStream">K</a>,<wbr><a href="KStream.html" title="type parameter in KStream">V</a>></code></div> |
| <div class="col-second odd-row-color method-summary-table method-summary-table-tab2 method-summary-table-tab3"><code><a href="#filterNot(org.apache.kafka.streams.kstream.Predicate,org.apache.kafka.streams.kstream.Named)" class="member-name-link">filterNot</a><wbr>(<a href="Predicate.html" title="interface in org.apache.kafka.streams.kstream">Predicate</a><? super <a href="KStream.html" title="type parameter in KStream">K</a>,<wbr>? super <a href="KStream.html" title="type parameter in KStream">V</a>> predicate, |
| <a href="Named.html" title="class in org.apache.kafka.streams.kstream">Named</a> named)</code></div> |
| <div class="col-last odd-row-color method-summary-table method-summary-table-tab2 method-summary-table-tab3"> |
| <div class="block">Create a new <code>KStream</code> that consists all records of this stream which do <em>not</em> satisfy the given |
| predicate.</div> |
| </div> |
| <div class="col-first even-row-color method-summary-table method-summary-table-tab2 method-summary-table-tab3"><code><KR,<wbr> |
| VR> <a href="KStream.html" title="interface in org.apache.kafka.streams.kstream">KStream</a><KR,<wbr>VR></code></div> |
| <div class="col-second even-row-color method-summary-table method-summary-table-tab2 method-summary-table-tab3"><code><a href="#flatMap(org.apache.kafka.streams.kstream.KeyValueMapper)" class="member-name-link">flatMap</a><wbr>(<a href="KeyValueMapper.html" title="interface in org.apache.kafka.streams.kstream">KeyValueMapper</a><? super <a href="KStream.html" title="type parameter in KStream">K</a>,<wbr>? super <a href="KStream.html" title="type parameter in KStream">V</a>,<wbr>? extends <a href="https://docs.oracle.com/en/java/javase/17/docs/api/java.base/java/lang/Iterable.html" title="class or interface in java.lang" class="external-link">Iterable</a><? extends <a href="../KeyValue.html" title="class in org.apache.kafka.streams">KeyValue</a><? extends KR,<wbr>? extends VR>>> mapper)</code></div> |
| <div class="col-last even-row-color method-summary-table method-summary-table-tab2 method-summary-table-tab3"> |
| <div class="block">Transform each record of the input stream into zero or more records in the output stream (both key and value type |
| can be altered arbitrarily).</div> |
| </div> |
| <div class="col-first odd-row-color method-summary-table method-summary-table-tab2 method-summary-table-tab3"><code><KR,<wbr> |
| VR> <a href="KStream.html" title="interface in org.apache.kafka.streams.kstream">KStream</a><KR,<wbr>VR></code></div> |
| <div class="col-second odd-row-color method-summary-table method-summary-table-tab2 method-summary-table-tab3"><code><a href="#flatMap(org.apache.kafka.streams.kstream.KeyValueMapper,org.apache.kafka.streams.kstream.Named)" class="member-name-link">flatMap</a><wbr>(<a href="KeyValueMapper.html" title="interface in org.apache.kafka.streams.kstream">KeyValueMapper</a><? super <a href="KStream.html" title="type parameter in KStream">K</a>,<wbr>? super <a href="KStream.html" title="type parameter in KStream">V</a>,<wbr>? extends <a href="https://docs.oracle.com/en/java/javase/17/docs/api/java.base/java/lang/Iterable.html" title="class or interface in java.lang" class="external-link">Iterable</a><? extends <a href="../KeyValue.html" title="class in org.apache.kafka.streams">KeyValue</a><? extends KR,<wbr>? extends VR>>> mapper, |
| <a href="Named.html" title="class in org.apache.kafka.streams.kstream">Named</a> named)</code></div> |
| <div class="col-last odd-row-color method-summary-table method-summary-table-tab2 method-summary-table-tab3"> |
| <div class="block">Transform each record of the input stream into zero or more records in the output stream (both key and value type |
| can be altered arbitrarily).</div> |
| </div> |
| <div class="col-first even-row-color method-summary-table method-summary-table-tab2 method-summary-table-tab3"><code><VR> <a href="KStream.html" title="interface in org.apache.kafka.streams.kstream">KStream</a><<a href="KStream.html" title="type parameter in KStream">K</a>,<wbr>VR></code></div> |
| <div class="col-second even-row-color method-summary-table method-summary-table-tab2 method-summary-table-tab3"><code><a href="#flatMapValues(org.apache.kafka.streams.kstream.ValueMapper)" class="member-name-link">flatMapValues</a><wbr>(<a href="ValueMapper.html" title="interface in org.apache.kafka.streams.kstream">ValueMapper</a><? super <a href="KStream.html" title="type parameter in KStream">V</a>,<wbr>? extends <a href="https://docs.oracle.com/en/java/javase/17/docs/api/java.base/java/lang/Iterable.html" title="class or interface in java.lang" class="external-link">Iterable</a><? extends VR>> mapper)</code></div> |
| <div class="col-last even-row-color method-summary-table method-summary-table-tab2 method-summary-table-tab3"> |
| <div class="block">Create a new <code>KStream</code> by transforming the value of each record in this stream into zero or more values |
| with the same key in the new stream.</div> |
| </div> |
| <div class="col-first odd-row-color method-summary-table method-summary-table-tab2 method-summary-table-tab3"><code><VR> <a href="KStream.html" title="interface in org.apache.kafka.streams.kstream">KStream</a><<a href="KStream.html" title="type parameter in KStream">K</a>,<wbr>VR></code></div> |
| <div class="col-second odd-row-color method-summary-table method-summary-table-tab2 method-summary-table-tab3"><code><a href="#flatMapValues(org.apache.kafka.streams.kstream.ValueMapper,org.apache.kafka.streams.kstream.Named)" class="member-name-link">flatMapValues</a><wbr>(<a href="ValueMapper.html" title="interface in org.apache.kafka.streams.kstream">ValueMapper</a><? super <a href="KStream.html" title="type parameter in KStream">V</a>,<wbr>? extends <a href="https://docs.oracle.com/en/java/javase/17/docs/api/java.base/java/lang/Iterable.html" title="class or interface in java.lang" class="external-link">Iterable</a><? extends VR>> mapper, |
| <a href="Named.html" title="class in org.apache.kafka.streams.kstream">Named</a> named)</code></div> |
| <div class="col-last odd-row-color method-summary-table method-summary-table-tab2 method-summary-table-tab3"> |
| <div class="block">Create a new <code>KStream</code> by transforming the value of each record in this stream into zero or more values |
| with the same key in the new stream.</div> |
| </div> |
| <div class="col-first even-row-color method-summary-table method-summary-table-tab2 method-summary-table-tab3"><code><VR> <a href="KStream.html" title="interface in org.apache.kafka.streams.kstream">KStream</a><<a href="KStream.html" title="type parameter in KStream">K</a>,<wbr>VR></code></div> |
| <div class="col-second even-row-color method-summary-table method-summary-table-tab2 method-summary-table-tab3"><code><a href="#flatMapValues(org.apache.kafka.streams.kstream.ValueMapperWithKey)" class="member-name-link">flatMapValues</a><wbr>(<a href="ValueMapperWithKey.html" title="interface in org.apache.kafka.streams.kstream">ValueMapperWithKey</a><? super <a href="KStream.html" title="type parameter in KStream">K</a>,<wbr>? super <a href="KStream.html" title="type parameter in KStream">V</a>,<wbr>? extends <a href="https://docs.oracle.com/en/java/javase/17/docs/api/java.base/java/lang/Iterable.html" title="class or interface in java.lang" class="external-link">Iterable</a><? extends VR>> mapper)</code></div> |
| <div class="col-last even-row-color method-summary-table method-summary-table-tab2 method-summary-table-tab3"> |
| <div class="block">Create a new <code>KStream</code> by transforming the value of each record in this stream into zero or more values |
| with the same key in the new stream.</div> |
| </div> |
| <div class="col-first odd-row-color method-summary-table method-summary-table-tab2 method-summary-table-tab3"><code><VR> <a href="KStream.html" title="interface in org.apache.kafka.streams.kstream">KStream</a><<a href="KStream.html" title="type parameter in KStream">K</a>,<wbr>VR></code></div> |
| <div class="col-second odd-row-color method-summary-table method-summary-table-tab2 method-summary-table-tab3"><code><a href="#flatMapValues(org.apache.kafka.streams.kstream.ValueMapperWithKey,org.apache.kafka.streams.kstream.Named)" class="member-name-link">flatMapValues</a><wbr>(<a href="ValueMapperWithKey.html" title="interface in org.apache.kafka.streams.kstream">ValueMapperWithKey</a><? super <a href="KStream.html" title="type parameter in KStream">K</a>,<wbr>? super <a href="KStream.html" title="type parameter in KStream">V</a>,<wbr>? extends <a href="https://docs.oracle.com/en/java/javase/17/docs/api/java.base/java/lang/Iterable.html" title="class or interface in java.lang" class="external-link">Iterable</a><? extends VR>> mapper, |
| <a href="Named.html" title="class in org.apache.kafka.streams.kstream">Named</a> named)</code></div> |
| <div class="col-last odd-row-color method-summary-table method-summary-table-tab2 method-summary-table-tab3"> |
| <div class="block">Create a new <code>KStream</code> by transforming the value of each record in this stream into zero or more values |
| with the same key in the new stream.</div> |
| </div> |
| <div class="col-first even-row-color method-summary-table method-summary-table-tab2 method-summary-table-tab3"><code><K1,<wbr> |
| V1> <a href="KStream.html" title="interface in org.apache.kafka.streams.kstream">KStream</a><K1,<wbr>V1></code></div> |
| <div class="col-second even-row-color method-summary-table method-summary-table-tab2 method-summary-table-tab3"><code><a href="#flatTransform(org.apache.kafka.streams.kstream.TransformerSupplier,java.lang.String...)" class="member-name-link">flatTransform</a><wbr>(<a href="TransformerSupplier.html" title="interface in org.apache.kafka.streams.kstream">TransformerSupplier</a><? super <a href="KStream.html" title="type parameter in KStream">K</a>,<wbr>? super <a href="KStream.html" title="type parameter in KStream">V</a>,<wbr><a href="https://docs.oracle.com/en/java/javase/17/docs/api/java.base/java/lang/Iterable.html" title="class or interface in java.lang" class="external-link">Iterable</a><<a href="../KeyValue.html" title="class in org.apache.kafka.streams">KeyValue</a><K1,<wbr>V1>>> transformerSupplier, |
| <a href="https://docs.oracle.com/en/java/javase/17/docs/api/java.base/java/lang/String.html" title="class or interface in java.lang" class="external-link">String</a>... stateStoreNames)</code></div> |
| <div class="col-last even-row-color method-summary-table method-summary-table-tab2 method-summary-table-tab3"> |
| <div class="block">Transform each record of the input stream into zero or more records in the output stream (both key and value type |
| can be altered arbitrarily).</div> |
| </div> |
| <div class="col-first odd-row-color method-summary-table method-summary-table-tab2 method-summary-table-tab3"><code><K1,<wbr> |
| V1> <a href="KStream.html" title="interface in org.apache.kafka.streams.kstream">KStream</a><K1,<wbr>V1></code></div> |
| <div class="col-second odd-row-color method-summary-table method-summary-table-tab2 method-summary-table-tab3"><code><a href="#flatTransform(org.apache.kafka.streams.kstream.TransformerSupplier,org.apache.kafka.streams.kstream.Named,java.lang.String...)" class="member-name-link">flatTransform</a><wbr>(<a href="TransformerSupplier.html" title="interface in org.apache.kafka.streams.kstream">TransformerSupplier</a><? super <a href="KStream.html" title="type parameter in KStream">K</a>,<wbr>? super <a href="KStream.html" title="type parameter in KStream">V</a>,<wbr><a href="https://docs.oracle.com/en/java/javase/17/docs/api/java.base/java/lang/Iterable.html" title="class or interface in java.lang" class="external-link">Iterable</a><<a href="../KeyValue.html" title="class in org.apache.kafka.streams">KeyValue</a><K1,<wbr>V1>>> transformerSupplier, |
| <a href="Named.html" title="class in org.apache.kafka.streams.kstream">Named</a> named, |
| <a href="https://docs.oracle.com/en/java/javase/17/docs/api/java.base/java/lang/String.html" title="class or interface in java.lang" class="external-link">String</a>... stateStoreNames)</code></div> |
| <div class="col-last odd-row-color method-summary-table method-summary-table-tab2 method-summary-table-tab3"> |
| <div class="block">Transform each record of the input stream into zero or more records in the output stream (both key and value type |
| can be altered arbitrarily).</div> |
| </div> |
| <div class="col-first even-row-color method-summary-table method-summary-table-tab2 method-summary-table-tab3"><code><VR> <a href="KStream.html" title="interface in org.apache.kafka.streams.kstream">KStream</a><<a href="KStream.html" title="type parameter in KStream">K</a>,<wbr>VR></code></div> |
| <div class="col-second even-row-color method-summary-table method-summary-table-tab2 method-summary-table-tab3"><code><a href="#flatTransformValues(org.apache.kafka.streams.kstream.ValueTransformerSupplier,java.lang.String...)" class="member-name-link">flatTransformValues</a><wbr>(<a href="ValueTransformerSupplier.html" title="interface in org.apache.kafka.streams.kstream">ValueTransformerSupplier</a><? super <a href="KStream.html" title="type parameter in KStream">V</a>,<wbr><a href="https://docs.oracle.com/en/java/javase/17/docs/api/java.base/java/lang/Iterable.html" title="class or interface in java.lang" class="external-link">Iterable</a><VR>> valueTransformerSupplier, |
| <a href="https://docs.oracle.com/en/java/javase/17/docs/api/java.base/java/lang/String.html" title="class or interface in java.lang" class="external-link">String</a>... stateStoreNames)</code></div> |
| <div class="col-last even-row-color method-summary-table method-summary-table-tab2 method-summary-table-tab3"> |
| <div class="block">Transform the value of each input record into zero or more new values (with possibly a new |
| type) and emit for each new value a record with the same key of the input record and the value.</div> |
| </div> |
| <div class="col-first odd-row-color method-summary-table method-summary-table-tab2 method-summary-table-tab3"><code><VR> <a href="KStream.html" title="interface in org.apache.kafka.streams.kstream">KStream</a><<a href="KStream.html" title="type parameter in KStream">K</a>,<wbr>VR></code></div> |
| <div class="col-second odd-row-color method-summary-table method-summary-table-tab2 method-summary-table-tab3"><code><a href="#flatTransformValues(org.apache.kafka.streams.kstream.ValueTransformerSupplier,org.apache.kafka.streams.kstream.Named,java.lang.String...)" class="member-name-link">flatTransformValues</a><wbr>(<a href="ValueTransformerSupplier.html" title="interface in org.apache.kafka.streams.kstream">ValueTransformerSupplier</a><? super <a href="KStream.html" title="type parameter in KStream">V</a>,<wbr><a href="https://docs.oracle.com/en/java/javase/17/docs/api/java.base/java/lang/Iterable.html" title="class or interface in java.lang" class="external-link">Iterable</a><VR>> valueTransformerSupplier, |
| <a href="Named.html" title="class in org.apache.kafka.streams.kstream">Named</a> named, |
| <a href="https://docs.oracle.com/en/java/javase/17/docs/api/java.base/java/lang/String.html" title="class or interface in java.lang" class="external-link">String</a>... stateStoreNames)</code></div> |
| <div class="col-last odd-row-color method-summary-table method-summary-table-tab2 method-summary-table-tab3"> |
| <div class="block">Transform the value of each input record into zero or more new values (with possibly a new |
| type) and emit for each new value a record with the same key of the input record and the value.</div> |
| </div> |
| <div class="col-first even-row-color method-summary-table method-summary-table-tab2 method-summary-table-tab3"><code><VR> <a href="KStream.html" title="interface in org.apache.kafka.streams.kstream">KStream</a><<a href="KStream.html" title="type parameter in KStream">K</a>,<wbr>VR></code></div> |
| <div class="col-second even-row-color method-summary-table method-summary-table-tab2 method-summary-table-tab3"><code><a href="#flatTransformValues(org.apache.kafka.streams.kstream.ValueTransformerWithKeySupplier,java.lang.String...)" class="member-name-link">flatTransformValues</a><wbr>(<a href="ValueTransformerWithKeySupplier.html" title="interface in org.apache.kafka.streams.kstream">ValueTransformerWithKeySupplier</a><? super <a href="KStream.html" title="type parameter in KStream">K</a>,<wbr>? super <a href="KStream.html" title="type parameter in KStream">V</a>,<wbr><a href="https://docs.oracle.com/en/java/javase/17/docs/api/java.base/java/lang/Iterable.html" title="class or interface in java.lang" class="external-link">Iterable</a><VR>> valueTransformerSupplier, |
| <a href="https://docs.oracle.com/en/java/javase/17/docs/api/java.base/java/lang/String.html" title="class or interface in java.lang" class="external-link">String</a>... stateStoreNames)</code></div> |
| <div class="col-last even-row-color method-summary-table method-summary-table-tab2 method-summary-table-tab3"> |
| <div class="block">Transform the value of each input record into zero or more new values (with possibly a new |
| type) and emit for each new value a record with the same key of the input record and the value.</div> |
| </div> |
| <div class="col-first odd-row-color method-summary-table method-summary-table-tab2 method-summary-table-tab3"><code><VR> <a href="KStream.html" title="interface in org.apache.kafka.streams.kstream">KStream</a><<a href="KStream.html" title="type parameter in KStream">K</a>,<wbr>VR></code></div> |
| <div class="col-second odd-row-color method-summary-table method-summary-table-tab2 method-summary-table-tab3"><code><a href="#flatTransformValues(org.apache.kafka.streams.kstream.ValueTransformerWithKeySupplier,org.apache.kafka.streams.kstream.Named,java.lang.String...)" class="member-name-link">flatTransformValues</a><wbr>(<a href="ValueTransformerWithKeySupplier.html" title="interface in org.apache.kafka.streams.kstream">ValueTransformerWithKeySupplier</a><? super <a href="KStream.html" title="type parameter in KStream">K</a>,<wbr>? super <a href="KStream.html" title="type parameter in KStream">V</a>,<wbr><a href="https://docs.oracle.com/en/java/javase/17/docs/api/java.base/java/lang/Iterable.html" title="class or interface in java.lang" class="external-link">Iterable</a><VR>> valueTransformerSupplier, |
| <a href="Named.html" title="class in org.apache.kafka.streams.kstream">Named</a> named, |
| <a href="https://docs.oracle.com/en/java/javase/17/docs/api/java.base/java/lang/String.html" title="class or interface in java.lang" class="external-link">String</a>... stateStoreNames)</code></div> |
| <div class="col-last odd-row-color method-summary-table method-summary-table-tab2 method-summary-table-tab3"> |
| <div class="block">Transform the value of each input record into zero or more new values (with possibly a new |
| type) and emit for each new value a record with the same key of the input record and the value.</div> |
| </div> |
| <div class="col-first even-row-color method-summary-table method-summary-table-tab2 method-summary-table-tab3"><code>void</code></div> |
| <div class="col-second even-row-color method-summary-table method-summary-table-tab2 method-summary-table-tab3"><code><a href="#foreach(org.apache.kafka.streams.kstream.ForeachAction)" class="member-name-link">foreach</a><wbr>(<a href="ForeachAction.html" title="interface in org.apache.kafka.streams.kstream">ForeachAction</a><? super <a href="KStream.html" title="type parameter in KStream">K</a>,<wbr>? super <a href="KStream.html" title="type parameter in KStream">V</a>> action)</code></div> |
| <div class="col-last even-row-color method-summary-table method-summary-table-tab2 method-summary-table-tab3"> |
| <div class="block">Perform an action on each record of <code>KStream</code>.</div> |
| </div> |
| <div class="col-first odd-row-color method-summary-table method-summary-table-tab2 method-summary-table-tab3"><code>void</code></div> |
| <div class="col-second odd-row-color method-summary-table method-summary-table-tab2 method-summary-table-tab3"><code><a href="#foreach(org.apache.kafka.streams.kstream.ForeachAction,org.apache.kafka.streams.kstream.Named)" class="member-name-link">foreach</a><wbr>(<a href="ForeachAction.html" title="interface in org.apache.kafka.streams.kstream">ForeachAction</a><? super <a href="KStream.html" title="type parameter in KStream">K</a>,<wbr>? super <a href="KStream.html" title="type parameter in KStream">V</a>> action, |
| <a href="Named.html" title="class in org.apache.kafka.streams.kstream">Named</a> named)</code></div> |
| <div class="col-last odd-row-color method-summary-table method-summary-table-tab2 method-summary-table-tab3"> |
| <div class="block">Perform an action on each record of <code>KStream</code>.</div> |
| </div> |
| <div class="col-first even-row-color method-summary-table method-summary-table-tab2 method-summary-table-tab3"><code><KR> <a href="KGroupedStream.html" title="interface in org.apache.kafka.streams.kstream">KGroupedStream</a><KR,<wbr><a href="KStream.html" title="type parameter in KStream">V</a>></code></div> |
| <div class="col-second even-row-color method-summary-table method-summary-table-tab2 method-summary-table-tab3"><code><a href="#groupBy(org.apache.kafka.streams.kstream.KeyValueMapper)" class="member-name-link">groupBy</a><wbr>(<a href="KeyValueMapper.html" title="interface in org.apache.kafka.streams.kstream">KeyValueMapper</a><? super <a href="KStream.html" title="type parameter in KStream">K</a>,<wbr>? super <a href="KStream.html" title="type parameter in KStream">V</a>,<wbr>KR> keySelector)</code></div> |
| <div class="col-last even-row-color method-summary-table method-summary-table-tab2 method-summary-table-tab3"> |
| <div class="block">Group the records of this <code>KStream</code> on a new key that is selected using the provided <a href="KeyValueMapper.html" title="interface in org.apache.kafka.streams.kstream"><code>KeyValueMapper</code></a> |
| and default serializers and deserializers.</div> |
| </div> |
| <div class="col-first odd-row-color method-summary-table method-summary-table-tab2 method-summary-table-tab3"><code><KR> <a href="KGroupedStream.html" title="interface in org.apache.kafka.streams.kstream">KGroupedStream</a><KR,<wbr><a href="KStream.html" title="type parameter in KStream">V</a>></code></div> |
| <div class="col-second odd-row-color method-summary-table method-summary-table-tab2 method-summary-table-tab3"><code><a href="#groupBy(org.apache.kafka.streams.kstream.KeyValueMapper,org.apache.kafka.streams.kstream.Grouped)" class="member-name-link">groupBy</a><wbr>(<a href="KeyValueMapper.html" title="interface in org.apache.kafka.streams.kstream">KeyValueMapper</a><? super <a href="KStream.html" title="type parameter in KStream">K</a>,<wbr>? super <a href="KStream.html" title="type parameter in KStream">V</a>,<wbr>KR> keySelector, |
| <a href="Grouped.html" title="class in org.apache.kafka.streams.kstream">Grouped</a><KR,<wbr><a href="KStream.html" title="type parameter in KStream">V</a>> grouped)</code></div> |
| <div class="col-last odd-row-color method-summary-table method-summary-table-tab2 method-summary-table-tab3"> |
| <div class="block">Group the records of this <code>KStream</code> on a new key that is selected using the provided <a href="KeyValueMapper.html" title="interface in org.apache.kafka.streams.kstream"><code>KeyValueMapper</code></a> |
| and <a href="../../common/serialization/Serde.html" title="interface in org.apache.kafka.common.serialization"><code>Serde</code></a>s as specified by <a href="Grouped.html" title="class in org.apache.kafka.streams.kstream"><code>Grouped</code></a>.</div> |
| </div> |
| <div class="col-first even-row-color method-summary-table method-summary-table-tab2 method-summary-table-tab3"><code><a href="KGroupedStream.html" title="interface in org.apache.kafka.streams.kstream">KGroupedStream</a><<a href="KStream.html" title="type parameter in KStream">K</a>,<wbr><a href="KStream.html" title="type parameter in KStream">V</a>></code></div> |
| <div class="col-second even-row-color method-summary-table method-summary-table-tab2 method-summary-table-tab3"><code><a href="#groupByKey()" class="member-name-link">groupByKey</a>()</code></div> |
| <div class="col-last even-row-color method-summary-table method-summary-table-tab2 method-summary-table-tab3"> |
| <div class="block">Group the records by their current key into a <a href="KGroupedStream.html" title="interface in org.apache.kafka.streams.kstream"><code>KGroupedStream</code></a> while preserving the original values |
| and default serializers and deserializers.</div> |
| </div> |
| <div class="col-first odd-row-color method-summary-table method-summary-table-tab2 method-summary-table-tab3"><code><a href="KGroupedStream.html" title="interface in org.apache.kafka.streams.kstream">KGroupedStream</a><<a href="KStream.html" title="type parameter in KStream">K</a>,<wbr><a href="KStream.html" title="type parameter in KStream">V</a>></code></div> |
| <div class="col-second odd-row-color method-summary-table method-summary-table-tab2 method-summary-table-tab3"><code><a href="#groupByKey(org.apache.kafka.streams.kstream.Grouped)" class="member-name-link">groupByKey</a><wbr>(<a href="Grouped.html" title="class in org.apache.kafka.streams.kstream">Grouped</a><<a href="KStream.html" title="type parameter in KStream">K</a>,<wbr><a href="KStream.html" title="type parameter in KStream">V</a>> grouped)</code></div> |
| <div class="col-last odd-row-color method-summary-table method-summary-table-tab2 method-summary-table-tab3"> |
| <div class="block">Group the records by their current key into a <a href="KGroupedStream.html" title="interface in org.apache.kafka.streams.kstream"><code>KGroupedStream</code></a> while preserving the original values |
| and using the serializers as defined by <a href="Grouped.html" title="class in org.apache.kafka.streams.kstream"><code>Grouped</code></a>.</div> |
| </div> |
| <div class="col-first even-row-color method-summary-table method-summary-table-tab2 method-summary-table-tab3"><code><GK,<wbr> |
| GV,<wbr> |
| RV> <a href="KStream.html" title="interface in org.apache.kafka.streams.kstream">KStream</a><<a href="KStream.html" title="type parameter in KStream">K</a>,<wbr>RV></code></div> |
| <div class="col-second even-row-color method-summary-table method-summary-table-tab2 method-summary-table-tab3"><code><a href="#join(org.apache.kafka.streams.kstream.GlobalKTable,org.apache.kafka.streams.kstream.KeyValueMapper,org.apache.kafka.streams.kstream.ValueJoiner)" class="member-name-link">join</a><wbr>(<a href="GlobalKTable.html" title="interface in org.apache.kafka.streams.kstream">GlobalKTable</a><GK,<wbr>GV> globalTable, |
| <a href="KeyValueMapper.html" title="interface in org.apache.kafka.streams.kstream">KeyValueMapper</a><? super <a href="KStream.html" title="type parameter in KStream">K</a>,<wbr>? super <a href="KStream.html" title="type parameter in KStream">V</a>,<wbr>? extends GK> keySelector, |
| <a href="ValueJoiner.html" title="interface in org.apache.kafka.streams.kstream">ValueJoiner</a><? super <a href="KStream.html" title="type parameter in KStream">V</a>,<wbr>? super GV,<wbr>? extends RV> joiner)</code></div> |
| <div class="col-last even-row-color method-summary-table method-summary-table-tab2 method-summary-table-tab3"> |
| <div class="block">Join records of this stream with <a href="GlobalKTable.html" title="interface in org.apache.kafka.streams.kstream"><code>GlobalKTable</code></a>'s records using non-windowed inner equi join.</div> |
| </div> |
| <div class="col-first odd-row-color method-summary-table method-summary-table-tab2 method-summary-table-tab3"><code><GK,<wbr> |
| GV,<wbr> |
| RV> <a href="KStream.html" title="interface in org.apache.kafka.streams.kstream">KStream</a><<a href="KStream.html" title="type parameter in KStream">K</a>,<wbr>RV></code></div> |
| <div class="col-second odd-row-color method-summary-table method-summary-table-tab2 method-summary-table-tab3"><code><a href="#join(org.apache.kafka.streams.kstream.GlobalKTable,org.apache.kafka.streams.kstream.KeyValueMapper,org.apache.kafka.streams.kstream.ValueJoiner,org.apache.kafka.streams.kstream.Named)" class="member-name-link">join</a><wbr>(<a href="GlobalKTable.html" title="interface in org.apache.kafka.streams.kstream">GlobalKTable</a><GK,<wbr>GV> globalTable, |
| <a href="KeyValueMapper.html" title="interface in org.apache.kafka.streams.kstream">KeyValueMapper</a><? super <a href="KStream.html" title="type parameter in KStream">K</a>,<wbr>? super <a href="KStream.html" title="type parameter in KStream">V</a>,<wbr>? extends GK> keySelector, |
| <a href="ValueJoiner.html" title="interface in org.apache.kafka.streams.kstream">ValueJoiner</a><? super <a href="KStream.html" title="type parameter in KStream">V</a>,<wbr>? super GV,<wbr>? extends RV> joiner, |
| <a href="Named.html" title="class in org.apache.kafka.streams.kstream">Named</a> named)</code></div> |
| <div class="col-last odd-row-color method-summary-table method-summary-table-tab2 method-summary-table-tab3"> |
| <div class="block">Join records of this stream with <a href="GlobalKTable.html" title="interface in org.apache.kafka.streams.kstream"><code>GlobalKTable</code></a>'s records using non-windowed inner equi join.</div> |
| </div> |
| <div class="col-first even-row-color method-summary-table method-summary-table-tab2 method-summary-table-tab3"><code><GK,<wbr> |
| GV,<wbr> |
| RV> <a href="KStream.html" title="interface in org.apache.kafka.streams.kstream">KStream</a><<a href="KStream.html" title="type parameter in KStream">K</a>,<wbr>RV></code></div> |
| <div class="col-second even-row-color method-summary-table method-summary-table-tab2 method-summary-table-tab3"><code><a href="#join(org.apache.kafka.streams.kstream.GlobalKTable,org.apache.kafka.streams.kstream.KeyValueMapper,org.apache.kafka.streams.kstream.ValueJoinerWithKey)" class="member-name-link">join</a><wbr>(<a href="GlobalKTable.html" title="interface in org.apache.kafka.streams.kstream">GlobalKTable</a><GK,<wbr>GV> globalTable, |
| <a href="KeyValueMapper.html" title="interface in org.apache.kafka.streams.kstream">KeyValueMapper</a><? super <a href="KStream.html" title="type parameter in KStream">K</a>,<wbr>? super <a href="KStream.html" title="type parameter in KStream">V</a>,<wbr>? extends GK> keySelector, |
| <a href="ValueJoinerWithKey.html" title="interface in org.apache.kafka.streams.kstream">ValueJoinerWithKey</a><? super <a href="KStream.html" title="type parameter in KStream">K</a>,<wbr>? super <a href="KStream.html" title="type parameter in KStream">V</a>,<wbr>? super GV,<wbr>? extends RV> joiner)</code></div> |
| <div class="col-last even-row-color method-summary-table method-summary-table-tab2 method-summary-table-tab3"> |
| <div class="block">Join records of this stream with <a href="GlobalKTable.html" title="interface in org.apache.kafka.streams.kstream"><code>GlobalKTable</code></a>'s records using non-windowed inner equi join.</div> |
| </div> |
| <div class="col-first odd-row-color method-summary-table method-summary-table-tab2 method-summary-table-tab3"><code><GK,<wbr> |
| GV,<wbr> |
| RV> <a href="KStream.html" title="interface in org.apache.kafka.streams.kstream">KStream</a><<a href="KStream.html" title="type parameter in KStream">K</a>,<wbr>RV></code></div> |
| <div class="col-second odd-row-color method-summary-table method-summary-table-tab2 method-summary-table-tab3"><code><a href="#join(org.apache.kafka.streams.kstream.GlobalKTable,org.apache.kafka.streams.kstream.KeyValueMapper,org.apache.kafka.streams.kstream.ValueJoinerWithKey,org.apache.kafka.streams.kstream.Named)" class="member-name-link">join</a><wbr>(<a href="GlobalKTable.html" title="interface in org.apache.kafka.streams.kstream">GlobalKTable</a><GK,<wbr>GV> globalTable, |
| <a href="KeyValueMapper.html" title="interface in org.apache.kafka.streams.kstream">KeyValueMapper</a><? super <a href="KStream.html" title="type parameter in KStream">K</a>,<wbr>? super <a href="KStream.html" title="type parameter in KStream">V</a>,<wbr>? extends GK> keySelector, |
| <a href="ValueJoinerWithKey.html" title="interface in org.apache.kafka.streams.kstream">ValueJoinerWithKey</a><? super <a href="KStream.html" title="type parameter in KStream">K</a>,<wbr>? super <a href="KStream.html" title="type parameter in KStream">V</a>,<wbr>? super GV,<wbr>? extends RV> joiner, |
| <a href="Named.html" title="class in org.apache.kafka.streams.kstream">Named</a> named)</code></div> |
| <div class="col-last odd-row-color method-summary-table method-summary-table-tab2 method-summary-table-tab3"> |
| <div class="block">Join records of this stream with <a href="GlobalKTable.html" title="interface in org.apache.kafka.streams.kstream"><code>GlobalKTable</code></a>'s records using non-windowed inner equi join.</div> |
| </div> |
| <div class="col-first even-row-color method-summary-table method-summary-table-tab2 method-summary-table-tab3"><code><VO,<wbr> |
| VR> <a href="KStream.html" title="interface in org.apache.kafka.streams.kstream">KStream</a><<a href="KStream.html" title="type parameter in KStream">K</a>,<wbr>VR></code></div> |
| <div class="col-second even-row-color method-summary-table method-summary-table-tab2 method-summary-table-tab3"><code><a href="#join(org.apache.kafka.streams.kstream.KStream,org.apache.kafka.streams.kstream.ValueJoiner,org.apache.kafka.streams.kstream.JoinWindows)" class="member-name-link">join</a><wbr>(<a href="KStream.html" title="interface in org.apache.kafka.streams.kstream">KStream</a><<a href="KStream.html" title="type parameter in KStream">K</a>,<wbr>VO> otherStream, |
| <a href="ValueJoiner.html" title="interface in org.apache.kafka.streams.kstream">ValueJoiner</a><? super <a href="KStream.html" title="type parameter in KStream">V</a>,<wbr>? super VO,<wbr>? extends VR> joiner, |
| <a href="JoinWindows.html" title="class in org.apache.kafka.streams.kstream">JoinWindows</a> windows)</code></div> |
| <div class="col-last even-row-color method-summary-table method-summary-table-tab2 method-summary-table-tab3"> |
| <div class="block">Join records of this stream with another <code>KStream</code>'s records using windowed inner equi join with default |
| serializers and deserializers.</div> |
| </div> |
| <div class="col-first odd-row-color method-summary-table method-summary-table-tab2 method-summary-table-tab3"><code><VO,<wbr> |
| VR> <a href="KStream.html" title="interface in org.apache.kafka.streams.kstream">KStream</a><<a href="KStream.html" title="type parameter in KStream">K</a>,<wbr>VR></code></div> |
| <div class="col-second odd-row-color method-summary-table method-summary-table-tab2 method-summary-table-tab3"><code><a href="#join(org.apache.kafka.streams.kstream.KStream,org.apache.kafka.streams.kstream.ValueJoiner,org.apache.kafka.streams.kstream.JoinWindows,org.apache.kafka.streams.kstream.StreamJoined)" class="member-name-link">join</a><wbr>(<a href="KStream.html" title="interface in org.apache.kafka.streams.kstream">KStream</a><<a href="KStream.html" title="type parameter in KStream">K</a>,<wbr>VO> otherStream, |
| <a href="ValueJoiner.html" title="interface in org.apache.kafka.streams.kstream">ValueJoiner</a><? super <a href="KStream.html" title="type parameter in KStream">V</a>,<wbr>? super VO,<wbr>? extends VR> joiner, |
| <a href="JoinWindows.html" title="class in org.apache.kafka.streams.kstream">JoinWindows</a> windows, |
| <a href="StreamJoined.html" title="class in org.apache.kafka.streams.kstream">StreamJoined</a><<a href="KStream.html" title="type parameter in KStream">K</a>,<wbr><a href="KStream.html" title="type parameter in KStream">V</a>,<wbr>VO> streamJoined)</code></div> |
| <div class="col-last odd-row-color method-summary-table method-summary-table-tab2 method-summary-table-tab3"> |
| <div class="block">Join records of this stream with another <code>KStream</code>'s records using windowed inner equi join using the |
| <a href="StreamJoined.html" title="class in org.apache.kafka.streams.kstream"><code>StreamJoined</code></a> instance for configuration of the <a href="../../common/serialization/Serde.html" title="interface in org.apache.kafka.common.serialization"><code>key serde</code></a>, <a href="../../common/serialization/Serde.html" title="interface in org.apache.kafka.common.serialization"><code>this stream's value |
| serde</code></a>, <a href="../../common/serialization/Serde.html" title="interface in org.apache.kafka.common.serialization"><code>the other stream's value serde</code></a>, and used state stores.</div> |
| </div> |
| <div class="col-first even-row-color method-summary-table method-summary-table-tab2 method-summary-table-tab3"><code><VO,<wbr> |
| VR> <a href="KStream.html" title="interface in org.apache.kafka.streams.kstream">KStream</a><<a href="KStream.html" title="type parameter in KStream">K</a>,<wbr>VR></code></div> |
| <div class="col-second even-row-color method-summary-table method-summary-table-tab2 method-summary-table-tab3"><code><a href="#join(org.apache.kafka.streams.kstream.KStream,org.apache.kafka.streams.kstream.ValueJoinerWithKey,org.apache.kafka.streams.kstream.JoinWindows)" class="member-name-link">join</a><wbr>(<a href="KStream.html" title="interface in org.apache.kafka.streams.kstream">KStream</a><<a href="KStream.html" title="type parameter in KStream">K</a>,<wbr>VO> otherStream, |
| <a href="ValueJoinerWithKey.html" title="interface in org.apache.kafka.streams.kstream">ValueJoinerWithKey</a><? super <a href="KStream.html" title="type parameter in KStream">K</a>,<wbr>? super <a href="KStream.html" title="type parameter in KStream">V</a>,<wbr>? super VO,<wbr>? extends VR> joiner, |
| <a href="JoinWindows.html" title="class in org.apache.kafka.streams.kstream">JoinWindows</a> windows)</code></div> |
| <div class="col-last even-row-color method-summary-table method-summary-table-tab2 method-summary-table-tab3"> |
| <div class="block">Join records of this stream with another <code>KStream</code>'s records using windowed inner equi join with default |
| serializers and deserializers.</div> |
| </div> |
| <div class="col-first odd-row-color method-summary-table method-summary-table-tab2 method-summary-table-tab3"><code><VO,<wbr> |
| VR> <a href="KStream.html" title="interface in org.apache.kafka.streams.kstream">KStream</a><<a href="KStream.html" title="type parameter in KStream">K</a>,<wbr>VR></code></div> |
| <div class="col-second odd-row-color method-summary-table method-summary-table-tab2 method-summary-table-tab3"><code><a href="#join(org.apache.kafka.streams.kstream.KStream,org.apache.kafka.streams.kstream.ValueJoinerWithKey,org.apache.kafka.streams.kstream.JoinWindows,org.apache.kafka.streams.kstream.StreamJoined)" class="member-name-link">join</a><wbr>(<a href="KStream.html" title="interface in org.apache.kafka.streams.kstream">KStream</a><<a href="KStream.html" title="type parameter in KStream">K</a>,<wbr>VO> otherStream, |
| <a href="ValueJoinerWithKey.html" title="interface in org.apache.kafka.streams.kstream">ValueJoinerWithKey</a><? super <a href="KStream.html" title="type parameter in KStream">K</a>,<wbr>? super <a href="KStream.html" title="type parameter in KStream">V</a>,<wbr>? super VO,<wbr>? extends VR> joiner, |
| <a href="JoinWindows.html" title="class in org.apache.kafka.streams.kstream">JoinWindows</a> windows, |
| <a href="StreamJoined.html" title="class in org.apache.kafka.streams.kstream">StreamJoined</a><<a href="KStream.html" title="type parameter in KStream">K</a>,<wbr><a href="KStream.html" title="type parameter in KStream">V</a>,<wbr>VO> streamJoined)</code></div> |
| <div class="col-last odd-row-color method-summary-table method-summary-table-tab2 method-summary-table-tab3"> |
| <div class="block">Join records of this stream with another <code>KStream</code>'s records using windowed inner equi join using the |
| <a href="StreamJoined.html" title="class in org.apache.kafka.streams.kstream"><code>StreamJoined</code></a> instance for configuration of the <a href="../../common/serialization/Serde.html" title="interface in org.apache.kafka.common.serialization"><code>key serde</code></a>, <a href="../../common/serialization/Serde.html" title="interface in org.apache.kafka.common.serialization"><code>this stream's value |
| serde</code></a>, <a href="../../common/serialization/Serde.html" title="interface in org.apache.kafka.common.serialization"><code>the other stream's value serde</code></a>, and used state stores.</div> |
| </div> |
| <div class="col-first even-row-color method-summary-table method-summary-table-tab2 method-summary-table-tab3"><code><VT,<wbr> |
| VR> <a href="KStream.html" title="interface in org.apache.kafka.streams.kstream">KStream</a><<a href="KStream.html" title="type parameter in KStream">K</a>,<wbr>VR></code></div> |
| <div class="col-second even-row-color method-summary-table method-summary-table-tab2 method-summary-table-tab3"><code><a href="#join(org.apache.kafka.streams.kstream.KTable,org.apache.kafka.streams.kstream.ValueJoiner)" class="member-name-link">join</a><wbr>(<a href="KTable.html" title="interface in org.apache.kafka.streams.kstream">KTable</a><<a href="KStream.html" title="type parameter in KStream">K</a>,<wbr>VT> table, |
| <a href="ValueJoiner.html" title="interface in org.apache.kafka.streams.kstream">ValueJoiner</a><? super <a href="KStream.html" title="type parameter in KStream">V</a>,<wbr>? super VT,<wbr>? extends VR> joiner)</code></div> |
| <div class="col-last even-row-color method-summary-table method-summary-table-tab2 method-summary-table-tab3"> |
| <div class="block">Join records of this stream with <a href="KTable.html" title="interface in org.apache.kafka.streams.kstream"><code>KTable</code></a>'s records using non-windowed inner equi join with default |
| serializers and deserializers.</div> |
| </div> |
| <div class="col-first odd-row-color method-summary-table method-summary-table-tab2 method-summary-table-tab3"><code><VT,<wbr> |
| VR> <a href="KStream.html" title="interface in org.apache.kafka.streams.kstream">KStream</a><<a href="KStream.html" title="type parameter in KStream">K</a>,<wbr>VR></code></div> |
| <div class="col-second odd-row-color method-summary-table method-summary-table-tab2 method-summary-table-tab3"><code><a href="#join(org.apache.kafka.streams.kstream.KTable,org.apache.kafka.streams.kstream.ValueJoiner,org.apache.kafka.streams.kstream.Joined)" class="member-name-link">join</a><wbr>(<a href="KTable.html" title="interface in org.apache.kafka.streams.kstream">KTable</a><<a href="KStream.html" title="type parameter in KStream">K</a>,<wbr>VT> table, |
| <a href="ValueJoiner.html" title="interface in org.apache.kafka.streams.kstream">ValueJoiner</a><? super <a href="KStream.html" title="type parameter in KStream">V</a>,<wbr>? super VT,<wbr>? extends VR> joiner, |
| <a href="Joined.html" title="class in org.apache.kafka.streams.kstream">Joined</a><<a href="KStream.html" title="type parameter in KStream">K</a>,<wbr><a href="KStream.html" title="type parameter in KStream">V</a>,<wbr>VT> joined)</code></div> |
| <div class="col-last odd-row-color method-summary-table method-summary-table-tab2 method-summary-table-tab3"> |
| <div class="block">Join records of this stream with <a href="KTable.html" title="interface in org.apache.kafka.streams.kstream"><code>KTable</code></a>'s records using non-windowed inner equi join with default |
| serializers and deserializers.</div> |
| </div> |
| <div class="col-first even-row-color method-summary-table method-summary-table-tab2 method-summary-table-tab3"><code><VT,<wbr> |
| VR> <a href="KStream.html" title="interface in org.apache.kafka.streams.kstream">KStream</a><<a href="KStream.html" title="type parameter in KStream">K</a>,<wbr>VR></code></div> |
| <div class="col-second even-row-color method-summary-table method-summary-table-tab2 method-summary-table-tab3"><code><a href="#join(org.apache.kafka.streams.kstream.KTable,org.apache.kafka.streams.kstream.ValueJoinerWithKey)" class="member-name-link">join</a><wbr>(<a href="KTable.html" title="interface in org.apache.kafka.streams.kstream">KTable</a><<a href="KStream.html" title="type parameter in KStream">K</a>,<wbr>VT> table, |
| <a href="ValueJoinerWithKey.html" title="interface in org.apache.kafka.streams.kstream">ValueJoinerWithKey</a><? super <a href="KStream.html" title="type parameter in KStream">K</a>,<wbr>? super <a href="KStream.html" title="type parameter in KStream">V</a>,<wbr>? super VT,<wbr>? extends VR> joiner)</code></div> |
| <div class="col-last even-row-color method-summary-table method-summary-table-tab2 method-summary-table-tab3"> |
| <div class="block">Join records of this stream with <a href="KTable.html" title="interface in org.apache.kafka.streams.kstream"><code>KTable</code></a>'s records using non-windowed inner equi join with default |
| serializers and deserializers.</div> |
| </div> |
| <div class="col-first odd-row-color method-summary-table method-summary-table-tab2 method-summary-table-tab3"><code><VT,<wbr> |
| VR> <a href="KStream.html" title="interface in org.apache.kafka.streams.kstream">KStream</a><<a href="KStream.html" title="type parameter in KStream">K</a>,<wbr>VR></code></div> |
| <div class="col-second odd-row-color method-summary-table method-summary-table-tab2 method-summary-table-tab3"><code><a href="#join(org.apache.kafka.streams.kstream.KTable,org.apache.kafka.streams.kstream.ValueJoinerWithKey,org.apache.kafka.streams.kstream.Joined)" class="member-name-link">join</a><wbr>(<a href="KTable.html" title="interface in org.apache.kafka.streams.kstream">KTable</a><<a href="KStream.html" title="type parameter in KStream">K</a>,<wbr>VT> table, |
| <a href="ValueJoinerWithKey.html" title="interface in org.apache.kafka.streams.kstream">ValueJoinerWithKey</a><? super <a href="KStream.html" title="type parameter in KStream">K</a>,<wbr>? super <a href="KStream.html" title="type parameter in KStream">V</a>,<wbr>? super VT,<wbr>? extends VR> joiner, |
| <a href="Joined.html" title="class in org.apache.kafka.streams.kstream">Joined</a><<a href="KStream.html" title="type parameter in KStream">K</a>,<wbr><a href="KStream.html" title="type parameter in KStream">V</a>,<wbr>VT> joined)</code></div> |
| <div class="col-last odd-row-color method-summary-table method-summary-table-tab2 method-summary-table-tab3"> |
| <div class="block">Join records of this stream with <a href="KTable.html" title="interface in org.apache.kafka.streams.kstream"><code>KTable</code></a>'s records using non-windowed inner equi join with default |
| serializers and deserializers.</div> |
| </div> |
| <div class="col-first even-row-color method-summary-table method-summary-table-tab2 method-summary-table-tab3"><code><GK,<wbr> |
| GV,<wbr> |
| RV> <a href="KStream.html" title="interface in org.apache.kafka.streams.kstream">KStream</a><<a href="KStream.html" title="type parameter in KStream">K</a>,<wbr>RV></code></div> |
| <div class="col-second even-row-color method-summary-table method-summary-table-tab2 method-summary-table-tab3"><code><a href="#leftJoin(org.apache.kafka.streams.kstream.GlobalKTable,org.apache.kafka.streams.kstream.KeyValueMapper,org.apache.kafka.streams.kstream.ValueJoiner)" class="member-name-link">leftJoin</a><wbr>(<a href="GlobalKTable.html" title="interface in org.apache.kafka.streams.kstream">GlobalKTable</a><GK,<wbr>GV> globalTable, |
| <a href="KeyValueMapper.html" title="interface in org.apache.kafka.streams.kstream">KeyValueMapper</a><? super <a href="KStream.html" title="type parameter in KStream">K</a>,<wbr>? super <a href="KStream.html" title="type parameter in KStream">V</a>,<wbr>? extends GK> keySelector, |
| <a href="ValueJoiner.html" title="interface in org.apache.kafka.streams.kstream">ValueJoiner</a><? super <a href="KStream.html" title="type parameter in KStream">V</a>,<wbr>? super GV,<wbr>? extends RV> valueJoiner)</code></div> |
| <div class="col-last even-row-color method-summary-table method-summary-table-tab2 method-summary-table-tab3"> |
| <div class="block">Join records of this stream with <a href="GlobalKTable.html" title="interface in org.apache.kafka.streams.kstream"><code>GlobalKTable</code></a>'s records using non-windowed left equi join.</div> |
| </div> |
| <div class="col-first odd-row-color method-summary-table method-summary-table-tab2 method-summary-table-tab3"><code><GK,<wbr> |
| GV,<wbr> |
| RV> <a href="KStream.html" title="interface in org.apache.kafka.streams.kstream">KStream</a><<a href="KStream.html" title="type parameter in KStream">K</a>,<wbr>RV></code></div> |
| <div class="col-second odd-row-color method-summary-table method-summary-table-tab2 method-summary-table-tab3"><code><a href="#leftJoin(org.apache.kafka.streams.kstream.GlobalKTable,org.apache.kafka.streams.kstream.KeyValueMapper,org.apache.kafka.streams.kstream.ValueJoiner,org.apache.kafka.streams.kstream.Named)" class="member-name-link">leftJoin</a><wbr>(<a href="GlobalKTable.html" title="interface in org.apache.kafka.streams.kstream">GlobalKTable</a><GK,<wbr>GV> globalTable, |
| <a href="KeyValueMapper.html" title="interface in org.apache.kafka.streams.kstream">KeyValueMapper</a><? super <a href="KStream.html" title="type parameter in KStream">K</a>,<wbr>? super <a href="KStream.html" title="type parameter in KStream">V</a>,<wbr>? extends GK> keySelector, |
| <a href="ValueJoiner.html" title="interface in org.apache.kafka.streams.kstream">ValueJoiner</a><? super <a href="KStream.html" title="type parameter in KStream">V</a>,<wbr>? super GV,<wbr>? extends RV> valueJoiner, |
| <a href="Named.html" title="class in org.apache.kafka.streams.kstream">Named</a> named)</code></div> |
| <div class="col-last odd-row-color method-summary-table method-summary-table-tab2 method-summary-table-tab3"> |
| <div class="block">Join records of this stream with <a href="GlobalKTable.html" title="interface in org.apache.kafka.streams.kstream"><code>GlobalKTable</code></a>'s records using non-windowed left equi join.</div> |
| </div> |
| <div class="col-first even-row-color method-summary-table method-summary-table-tab2 method-summary-table-tab3"><code><GK,<wbr> |
| GV,<wbr> |
| RV> <a href="KStream.html" title="interface in org.apache.kafka.streams.kstream">KStream</a><<a href="KStream.html" title="type parameter in KStream">K</a>,<wbr>RV></code></div> |
| <div class="col-second even-row-color method-summary-table method-summary-table-tab2 method-summary-table-tab3"><code><a href="#leftJoin(org.apache.kafka.streams.kstream.GlobalKTable,org.apache.kafka.streams.kstream.KeyValueMapper,org.apache.kafka.streams.kstream.ValueJoinerWithKey)" class="member-name-link">leftJoin</a><wbr>(<a href="GlobalKTable.html" title="interface in org.apache.kafka.streams.kstream">GlobalKTable</a><GK,<wbr>GV> globalTable, |
| <a href="KeyValueMapper.html" title="interface in org.apache.kafka.streams.kstream">KeyValueMapper</a><? super <a href="KStream.html" title="type parameter in KStream">K</a>,<wbr>? super <a href="KStream.html" title="type parameter in KStream">V</a>,<wbr>? extends GK> keySelector, |
| <a href="ValueJoinerWithKey.html" title="interface in org.apache.kafka.streams.kstream">ValueJoinerWithKey</a><? super <a href="KStream.html" title="type parameter in KStream">K</a>,<wbr>? super <a href="KStream.html" title="type parameter in KStream">V</a>,<wbr>? super GV,<wbr>? extends RV> valueJoiner)</code></div> |
| <div class="col-last even-row-color method-summary-table method-summary-table-tab2 method-summary-table-tab3"> |
| <div class="block">Join records of this stream with <a href="GlobalKTable.html" title="interface in org.apache.kafka.streams.kstream"><code>GlobalKTable</code></a>'s records using non-windowed left equi join.</div> |
| </div> |
| <div class="col-first odd-row-color method-summary-table method-summary-table-tab2 method-summary-table-tab3"><code><GK,<wbr> |
| GV,<wbr> |
| RV> <a href="KStream.html" title="interface in org.apache.kafka.streams.kstream">KStream</a><<a href="KStream.html" title="type parameter in KStream">K</a>,<wbr>RV></code></div> |
| <div class="col-second odd-row-color method-summary-table method-summary-table-tab2 method-summary-table-tab3"><code><a href="#leftJoin(org.apache.kafka.streams.kstream.GlobalKTable,org.apache.kafka.streams.kstream.KeyValueMapper,org.apache.kafka.streams.kstream.ValueJoinerWithKey,org.apache.kafka.streams.kstream.Named)" class="member-name-link">leftJoin</a><wbr>(<a href="GlobalKTable.html" title="interface in org.apache.kafka.streams.kstream">GlobalKTable</a><GK,<wbr>GV> globalTable, |
| <a href="KeyValueMapper.html" title="interface in org.apache.kafka.streams.kstream">KeyValueMapper</a><? super <a href="KStream.html" title="type parameter in KStream">K</a>,<wbr>? super <a href="KStream.html" title="type parameter in KStream">V</a>,<wbr>? extends GK> keySelector, |
| <a href="ValueJoinerWithKey.html" title="interface in org.apache.kafka.streams.kstream">ValueJoinerWithKey</a><? super <a href="KStream.html" title="type parameter in KStream">K</a>,<wbr>? super <a href="KStream.html" title="type parameter in KStream">V</a>,<wbr>? super GV,<wbr>? extends RV> valueJoiner, |
| <a href="Named.html" title="class in org.apache.kafka.streams.kstream">Named</a> named)</code></div> |
| <div class="col-last odd-row-color method-summary-table method-summary-table-tab2 method-summary-table-tab3"> |
| <div class="block">Join records of this stream with <a href="GlobalKTable.html" title="interface in org.apache.kafka.streams.kstream"><code>GlobalKTable</code></a>'s records using non-windowed left equi join.</div> |
| </div> |
| <div class="col-first even-row-color method-summary-table method-summary-table-tab2 method-summary-table-tab3"><code><VO,<wbr> |
| VR> <a href="KStream.html" title="interface in org.apache.kafka.streams.kstream">KStream</a><<a href="KStream.html" title="type parameter in KStream">K</a>,<wbr>VR></code></div> |
| <div class="col-second even-row-color method-summary-table method-summary-table-tab2 method-summary-table-tab3"><code><a href="#leftJoin(org.apache.kafka.streams.kstream.KStream,org.apache.kafka.streams.kstream.ValueJoiner,org.apache.kafka.streams.kstream.JoinWindows)" class="member-name-link">leftJoin</a><wbr>(<a href="KStream.html" title="interface in org.apache.kafka.streams.kstream">KStream</a><<a href="KStream.html" title="type parameter in KStream">K</a>,<wbr>VO> otherStream, |
| <a href="ValueJoiner.html" title="interface in org.apache.kafka.streams.kstream">ValueJoiner</a><? super <a href="KStream.html" title="type parameter in KStream">V</a>,<wbr>? super VO,<wbr>? extends VR> joiner, |
| <a href="JoinWindows.html" title="class in org.apache.kafka.streams.kstream">JoinWindows</a> windows)</code></div> |
| <div class="col-last even-row-color method-summary-table method-summary-table-tab2 method-summary-table-tab3"> |
| <div class="block">Join records of this stream with another <code>KStream</code>'s records using windowed left equi join with default |
| serializers and deserializers.</div> |
| </div> |
| <div class="col-first odd-row-color method-summary-table method-summary-table-tab2 method-summary-table-tab3"><code><VO,<wbr> |
| VR> <a href="KStream.html" title="interface in org.apache.kafka.streams.kstream">KStream</a><<a href="KStream.html" title="type parameter in KStream">K</a>,<wbr>VR></code></div> |
| <div class="col-second odd-row-color method-summary-table method-summary-table-tab2 method-summary-table-tab3"><code><a href="#leftJoin(org.apache.kafka.streams.kstream.KStream,org.apache.kafka.streams.kstream.ValueJoiner,org.apache.kafka.streams.kstream.JoinWindows,org.apache.kafka.streams.kstream.StreamJoined)" class="member-name-link">leftJoin</a><wbr>(<a href="KStream.html" title="interface in org.apache.kafka.streams.kstream">KStream</a><<a href="KStream.html" title="type parameter in KStream">K</a>,<wbr>VO> otherStream, |
| <a href="ValueJoiner.html" title="interface in org.apache.kafka.streams.kstream">ValueJoiner</a><? super <a href="KStream.html" title="type parameter in KStream">V</a>,<wbr>? super VO,<wbr>? extends VR> joiner, |
| <a href="JoinWindows.html" title="class in org.apache.kafka.streams.kstream">JoinWindows</a> windows, |
| <a href="StreamJoined.html" title="class in org.apache.kafka.streams.kstream">StreamJoined</a><<a href="KStream.html" title="type parameter in KStream">K</a>,<wbr><a href="KStream.html" title="type parameter in KStream">V</a>,<wbr>VO> streamJoined)</code></div> |
| <div class="col-last odd-row-color method-summary-table method-summary-table-tab2 method-summary-table-tab3"> |
| <div class="block">Join records of this stream with another <code>KStream</code>'s records using windowed left equi join using the |
| <a href="StreamJoined.html" title="class in org.apache.kafka.streams.kstream"><code>StreamJoined</code></a> instance for configuration of the <a href="../../common/serialization/Serde.html" title="interface in org.apache.kafka.common.serialization"><code>key serde</code></a>, <a href="../../common/serialization/Serde.html" title="interface in org.apache.kafka.common.serialization"><code>this stream's value |
| serde</code></a>, <a href="../../common/serialization/Serde.html" title="interface in org.apache.kafka.common.serialization"><code>the other stream's value serde</code></a>, and used state stores.</div> |
| </div> |
| <div class="col-first even-row-color method-summary-table method-summary-table-tab2 method-summary-table-tab3"><code><VO,<wbr> |
| VR> <a href="KStream.html" title="interface in org.apache.kafka.streams.kstream">KStream</a><<a href="KStream.html" title="type parameter in KStream">K</a>,<wbr>VR></code></div> |
| <div class="col-second even-row-color method-summary-table method-summary-table-tab2 method-summary-table-tab3"><code><a href="#leftJoin(org.apache.kafka.streams.kstream.KStream,org.apache.kafka.streams.kstream.ValueJoinerWithKey,org.apache.kafka.streams.kstream.JoinWindows)" class="member-name-link">leftJoin</a><wbr>(<a href="KStream.html" title="interface in org.apache.kafka.streams.kstream">KStream</a><<a href="KStream.html" title="type parameter in KStream">K</a>,<wbr>VO> otherStream, |
| <a href="ValueJoinerWithKey.html" title="interface in org.apache.kafka.streams.kstream">ValueJoinerWithKey</a><? super <a href="KStream.html" title="type parameter in KStream">K</a>,<wbr>? super <a href="KStream.html" title="type parameter in KStream">V</a>,<wbr>? super VO,<wbr>? extends VR> joiner, |
| <a href="JoinWindows.html" title="class in org.apache.kafka.streams.kstream">JoinWindows</a> windows)</code></div> |
| <div class="col-last even-row-color method-summary-table method-summary-table-tab2 method-summary-table-tab3"> |
| <div class="block">Join records of this stream with another <code>KStream</code>'s records using windowed left equi join with default |
| serializers and deserializers.</div> |
| </div> |
| <div class="col-first odd-row-color method-summary-table method-summary-table-tab2 method-summary-table-tab3"><code><VO,<wbr> |
| VR> <a href="KStream.html" title="interface in org.apache.kafka.streams.kstream">KStream</a><<a href="KStream.html" title="type parameter in KStream">K</a>,<wbr>VR></code></div> |
| <div class="col-second odd-row-color method-summary-table method-summary-table-tab2 method-summary-table-tab3"><code><a href="#leftJoin(org.apache.kafka.streams.kstream.KStream,org.apache.kafka.streams.kstream.ValueJoinerWithKey,org.apache.kafka.streams.kstream.JoinWindows,org.apache.kafka.streams.kstream.StreamJoined)" class="member-name-link">leftJoin</a><wbr>(<a href="KStream.html" title="interface in org.apache.kafka.streams.kstream">KStream</a><<a href="KStream.html" title="type parameter in KStream">K</a>,<wbr>VO> otherStream, |
| <a href="ValueJoinerWithKey.html" title="interface in org.apache.kafka.streams.kstream">ValueJoinerWithKey</a><? super <a href="KStream.html" title="type parameter in KStream">K</a>,<wbr>? super <a href="KStream.html" title="type parameter in KStream">V</a>,<wbr>? super VO,<wbr>? extends VR> joiner, |
| <a href="JoinWindows.html" title="class in org.apache.kafka.streams.kstream">JoinWindows</a> windows, |
| <a href="StreamJoined.html" title="class in org.apache.kafka.streams.kstream">StreamJoined</a><<a href="KStream.html" title="type parameter in KStream">K</a>,<wbr><a href="KStream.html" title="type parameter in KStream">V</a>,<wbr>VO> streamJoined)</code></div> |
| <div class="col-last odd-row-color method-summary-table method-summary-table-tab2 method-summary-table-tab3"> |
| <div class="block">Join records of this stream with another <code>KStream</code>'s records using windowed left equi join using the |
| <a href="StreamJoined.html" title="class in org.apache.kafka.streams.kstream"><code>StreamJoined</code></a> instance for configuration of the <a href="../../common/serialization/Serde.html" title="interface in org.apache.kafka.common.serialization"><code>key serde</code></a>, <a href="../../common/serialization/Serde.html" title="interface in org.apache.kafka.common.serialization"><code>this stream's value |
| serde</code></a>, <a href="../../common/serialization/Serde.html" title="interface in org.apache.kafka.common.serialization"><code>the other stream's value serde</code></a>, and used state stores.</div> |
| </div> |
| <div class="col-first even-row-color method-summary-table method-summary-table-tab2 method-summary-table-tab3"><code><VT,<wbr> |
| VR> <a href="KStream.html" title="interface in org.apache.kafka.streams.kstream">KStream</a><<a href="KStream.html" title="type parameter in KStream">K</a>,<wbr>VR></code></div> |
| <div class="col-second even-row-color method-summary-table method-summary-table-tab2 method-summary-table-tab3"><code><a href="#leftJoin(org.apache.kafka.streams.kstream.KTable,org.apache.kafka.streams.kstream.ValueJoiner)" class="member-name-link">leftJoin</a><wbr>(<a href="KTable.html" title="interface in org.apache.kafka.streams.kstream">KTable</a><<a href="KStream.html" title="type parameter in KStream">K</a>,<wbr>VT> table, |
| <a href="ValueJoiner.html" title="interface in org.apache.kafka.streams.kstream">ValueJoiner</a><? super <a href="KStream.html" title="type parameter in KStream">V</a>,<wbr>? super VT,<wbr>? extends VR> joiner)</code></div> |
| <div class="col-last even-row-color method-summary-table method-summary-table-tab2 method-summary-table-tab3"> |
| <div class="block">Join records of this stream with <a href="KTable.html" title="interface in org.apache.kafka.streams.kstream"><code>KTable</code></a>'s records using non-windowed left equi join with default |
| serializers and deserializers.</div> |
| </div> |
| <div class="col-first odd-row-color method-summary-table method-summary-table-tab2 method-summary-table-tab3"><code><VT,<wbr> |
| VR> <a href="KStream.html" title="interface in org.apache.kafka.streams.kstream">KStream</a><<a href="KStream.html" title="type parameter in KStream">K</a>,<wbr>VR></code></div> |
| <div class="col-second odd-row-color method-summary-table method-summary-table-tab2 method-summary-table-tab3"><code><a href="#leftJoin(org.apache.kafka.streams.kstream.KTable,org.apache.kafka.streams.kstream.ValueJoiner,org.apache.kafka.streams.kstream.Joined)" class="member-name-link">leftJoin</a><wbr>(<a href="KTable.html" title="interface in org.apache.kafka.streams.kstream">KTable</a><<a href="KStream.html" title="type parameter in KStream">K</a>,<wbr>VT> table, |
| <a href="ValueJoiner.html" title="interface in org.apache.kafka.streams.kstream">ValueJoiner</a><? super <a href="KStream.html" title="type parameter in KStream">V</a>,<wbr>? super VT,<wbr>? extends VR> joiner, |
| <a href="Joined.html" title="class in org.apache.kafka.streams.kstream">Joined</a><<a href="KStream.html" title="type parameter in KStream">K</a>,<wbr><a href="KStream.html" title="type parameter in KStream">V</a>,<wbr>VT> joined)</code></div> |
| <div class="col-last odd-row-color method-summary-table method-summary-table-tab2 method-summary-table-tab3"> |
| <div class="block">Join records of this stream with <a href="KTable.html" title="interface in org.apache.kafka.streams.kstream"><code>KTable</code></a>'s records using non-windowed left equi join with default |
| serializers and deserializers.</div> |
| </div> |
| <div class="col-first even-row-color method-summary-table method-summary-table-tab2 method-summary-table-tab3"><code><VT,<wbr> |
| VR> <a href="KStream.html" title="interface in org.apache.kafka.streams.kstream">KStream</a><<a href="KStream.html" title="type parameter in KStream">K</a>,<wbr>VR></code></div> |
| <div class="col-second even-row-color method-summary-table method-summary-table-tab2 method-summary-table-tab3"><code><a href="#leftJoin(org.apache.kafka.streams.kstream.KTable,org.apache.kafka.streams.kstream.ValueJoinerWithKey)" class="member-name-link">leftJoin</a><wbr>(<a href="KTable.html" title="interface in org.apache.kafka.streams.kstream">KTable</a><<a href="KStream.html" title="type parameter in KStream">K</a>,<wbr>VT> table, |
| <a href="ValueJoinerWithKey.html" title="interface in org.apache.kafka.streams.kstream">ValueJoinerWithKey</a><? super <a href="KStream.html" title="type parameter in KStream">K</a>,<wbr>? super <a href="KStream.html" title="type parameter in KStream">V</a>,<wbr>? super VT,<wbr>? extends VR> joiner)</code></div> |
| <div class="col-last even-row-color method-summary-table method-summary-table-tab2 method-summary-table-tab3"> |
| <div class="block">Join records of this stream with <a href="KTable.html" title="interface in org.apache.kafka.streams.kstream"><code>KTable</code></a>'s records using non-windowed left equi join with default |
| serializers and deserializers.</div> |
| </div> |
| <div class="col-first odd-row-color method-summary-table method-summary-table-tab2 method-summary-table-tab3"><code><VT,<wbr> |
| VR> <a href="KStream.html" title="interface in org.apache.kafka.streams.kstream">KStream</a><<a href="KStream.html" title="type parameter in KStream">K</a>,<wbr>VR></code></div> |
| <div class="col-second odd-row-color method-summary-table method-summary-table-tab2 method-summary-table-tab3"><code><a href="#leftJoin(org.apache.kafka.streams.kstream.KTable,org.apache.kafka.streams.kstream.ValueJoinerWithKey,org.apache.kafka.streams.kstream.Joined)" class="member-name-link">leftJoin</a><wbr>(<a href="KTable.html" title="interface in org.apache.kafka.streams.kstream">KTable</a><<a href="KStream.html" title="type parameter in KStream">K</a>,<wbr>VT> table, |
| <a href="ValueJoinerWithKey.html" title="interface in org.apache.kafka.streams.kstream">ValueJoinerWithKey</a><? super <a href="KStream.html" title="type parameter in KStream">K</a>,<wbr>? super <a href="KStream.html" title="type parameter in KStream">V</a>,<wbr>? super VT,<wbr>? extends VR> joiner, |
| <a href="Joined.html" title="class in org.apache.kafka.streams.kstream">Joined</a><<a href="KStream.html" title="type parameter in KStream">K</a>,<wbr><a href="KStream.html" title="type parameter in KStream">V</a>,<wbr>VT> joined)</code></div> |
| <div class="col-last odd-row-color method-summary-table method-summary-table-tab2 method-summary-table-tab3"> |
| <div class="block">Join records of this stream with <a href="KTable.html" title="interface in org.apache.kafka.streams.kstream"><code>KTable</code></a>'s records using non-windowed left equi join with default |
| serializers and deserializers.</div> |
| </div> |
| <div class="col-first even-row-color method-summary-table method-summary-table-tab2 method-summary-table-tab3"><code><KR,<wbr> |
| VR> <a href="KStream.html" title="interface in org.apache.kafka.streams.kstream">KStream</a><KR,<wbr>VR></code></div> |
| <div class="col-second even-row-color method-summary-table method-summary-table-tab2 method-summary-table-tab3"><code><a href="#map(org.apache.kafka.streams.kstream.KeyValueMapper)" class="member-name-link">map</a><wbr>(<a href="KeyValueMapper.html" title="interface in org.apache.kafka.streams.kstream">KeyValueMapper</a><? super <a href="KStream.html" title="type parameter in KStream">K</a>,<wbr>? super <a href="KStream.html" title="type parameter in KStream">V</a>,<wbr>? extends <a href="../KeyValue.html" title="class in org.apache.kafka.streams">KeyValue</a><? extends KR,<wbr>? extends VR>> mapper)</code></div> |
| <div class="col-last even-row-color method-summary-table method-summary-table-tab2 method-summary-table-tab3"> |
| <div class="block">Transform each record of the input stream into a new record in the output stream (both key and value type can be |
| altered arbitrarily).</div> |
| </div> |
| <div class="col-first odd-row-color method-summary-table method-summary-table-tab2 method-summary-table-tab3"><code><KR,<wbr> |
| VR> <a href="KStream.html" title="interface in org.apache.kafka.streams.kstream">KStream</a><KR,<wbr>VR></code></div> |
| <div class="col-second odd-row-color method-summary-table method-summary-table-tab2 method-summary-table-tab3"><code><a href="#map(org.apache.kafka.streams.kstream.KeyValueMapper,org.apache.kafka.streams.kstream.Named)" class="member-name-link">map</a><wbr>(<a href="KeyValueMapper.html" title="interface in org.apache.kafka.streams.kstream">KeyValueMapper</a><? super <a href="KStream.html" title="type parameter in KStream">K</a>,<wbr>? super <a href="KStream.html" title="type parameter in KStream">V</a>,<wbr>? extends <a href="../KeyValue.html" title="class in org.apache.kafka.streams">KeyValue</a><? extends KR,<wbr>? extends VR>> mapper, |
| <a href="Named.html" title="class in org.apache.kafka.streams.kstream">Named</a> named)</code></div> |
| <div class="col-last odd-row-color method-summary-table method-summary-table-tab2 method-summary-table-tab3"> |
| <div class="block">Transform each record of the input stream into a new record in the output stream (both key and value type can be |
| altered arbitrarily).</div> |
| </div> |
| <div class="col-first even-row-color method-summary-table method-summary-table-tab2 method-summary-table-tab3"><code><VR> <a href="KStream.html" title="interface in org.apache.kafka.streams.kstream">KStream</a><<a href="KStream.html" title="type parameter in KStream">K</a>,<wbr>VR></code></div> |
| <div class="col-second even-row-color method-summary-table method-summary-table-tab2 method-summary-table-tab3"><code><a href="#mapValues(org.apache.kafka.streams.kstream.ValueMapper)" class="member-name-link">mapValues</a><wbr>(<a href="ValueMapper.html" title="interface in org.apache.kafka.streams.kstream">ValueMapper</a><? super <a href="KStream.html" title="type parameter in KStream">V</a>,<wbr>? extends VR> mapper)</code></div> |
| <div class="col-last even-row-color method-summary-table method-summary-table-tab2 method-summary-table-tab3"> |
| <div class="block">Transform the value of each input record into a new value (with possible new type) of the output record.</div> |
| </div> |
| <div class="col-first odd-row-color method-summary-table method-summary-table-tab2 method-summary-table-tab3"><code><VR> <a href="KStream.html" title="interface in org.apache.kafka.streams.kstream">KStream</a><<a href="KStream.html" title="type parameter in KStream">K</a>,<wbr>VR></code></div> |
| <div class="col-second odd-row-color method-summary-table method-summary-table-tab2 method-summary-table-tab3"><code><a href="#mapValues(org.apache.kafka.streams.kstream.ValueMapper,org.apache.kafka.streams.kstream.Named)" class="member-name-link">mapValues</a><wbr>(<a href="ValueMapper.html" title="interface in org.apache.kafka.streams.kstream">ValueMapper</a><? super <a href="KStream.html" title="type parameter in KStream">V</a>,<wbr>? extends VR> mapper, |
| <a href="Named.html" title="class in org.apache.kafka.streams.kstream">Named</a> named)</code></div> |
| <div class="col-last odd-row-color method-summary-table method-summary-table-tab2 method-summary-table-tab3"> |
| <div class="block">Transform the value of each input record into a new value (with possible new type) of the output record.</div> |
| </div> |
| <div class="col-first even-row-color method-summary-table method-summary-table-tab2 method-summary-table-tab3"><code><VR> <a href="KStream.html" title="interface in org.apache.kafka.streams.kstream">KStream</a><<a href="KStream.html" title="type parameter in KStream">K</a>,<wbr>VR></code></div> |
| <div class="col-second even-row-color method-summary-table method-summary-table-tab2 method-summary-table-tab3"><code><a href="#mapValues(org.apache.kafka.streams.kstream.ValueMapperWithKey)" class="member-name-link">mapValues</a><wbr>(<a href="ValueMapperWithKey.html" title="interface in org.apache.kafka.streams.kstream">ValueMapperWithKey</a><? super <a href="KStream.html" title="type parameter in KStream">K</a>,<wbr>? super <a href="KStream.html" title="type parameter in KStream">V</a>,<wbr>? extends VR> mapper)</code></div> |
| <div class="col-last even-row-color method-summary-table method-summary-table-tab2 method-summary-table-tab3"> |
| <div class="block">Transform the value of each input record into a new value (with possible new type) of the output record.</div> |
| </div> |
| <div class="col-first odd-row-color method-summary-table method-summary-table-tab2 method-summary-table-tab3"><code><VR> <a href="KStream.html" title="interface in org.apache.kafka.streams.kstream">KStream</a><<a href="KStream.html" title="type parameter in KStream">K</a>,<wbr>VR></code></div> |
| <div class="col-second odd-row-color method-summary-table method-summary-table-tab2 method-summary-table-tab3"><code><a href="#mapValues(org.apache.kafka.streams.kstream.ValueMapperWithKey,org.apache.kafka.streams.kstream.Named)" class="member-name-link">mapValues</a><wbr>(<a href="ValueMapperWithKey.html" title="interface in org.apache.kafka.streams.kstream">ValueMapperWithKey</a><? super <a href="KStream.html" title="type parameter in KStream">K</a>,<wbr>? super <a href="KStream.html" title="type parameter in KStream">V</a>,<wbr>? extends VR> mapper, |
| <a href="Named.html" title="class in org.apache.kafka.streams.kstream">Named</a> named)</code></div> |
| <div class="col-last odd-row-color method-summary-table method-summary-table-tab2 method-summary-table-tab3"> |
| <div class="block">Transform the value of each input record into a new value (with possible new type) of the output record.</div> |
| </div> |
| <div class="col-first even-row-color method-summary-table method-summary-table-tab2 method-summary-table-tab3"><code><a href="KStream.html" title="interface in org.apache.kafka.streams.kstream">KStream</a><<a href="KStream.html" title="type parameter in KStream">K</a>,<wbr><a href="KStream.html" title="type parameter in KStream">V</a>></code></div> |
| <div class="col-second even-row-color method-summary-table method-summary-table-tab2 method-summary-table-tab3"><code><a href="#merge(org.apache.kafka.streams.kstream.KStream)" class="member-name-link">merge</a><wbr>(<a href="KStream.html" title="interface in org.apache.kafka.streams.kstream">KStream</a><<a href="KStream.html" title="type parameter in KStream">K</a>,<wbr><a href="KStream.html" title="type parameter in KStream">V</a>> stream)</code></div> |
| <div class="col-last even-row-color method-summary-table method-summary-table-tab2 method-summary-table-tab3"> |
| <div class="block">Merge this stream and the given stream into one larger stream.</div> |
| </div> |
| <div class="col-first odd-row-color method-summary-table method-summary-table-tab2 method-summary-table-tab3"><code><a href="KStream.html" title="interface in org.apache.kafka.streams.kstream">KStream</a><<a href="KStream.html" title="type parameter in KStream">K</a>,<wbr><a href="KStream.html" title="type parameter in KStream">V</a>></code></div> |
| <div class="col-second odd-row-color method-summary-table method-summary-table-tab2 method-summary-table-tab3"><code><a href="#merge(org.apache.kafka.streams.kstream.KStream,org.apache.kafka.streams.kstream.Named)" class="member-name-link">merge</a><wbr>(<a href="KStream.html" title="interface in org.apache.kafka.streams.kstream">KStream</a><<a href="KStream.html" title="type parameter in KStream">K</a>,<wbr><a href="KStream.html" title="type parameter in KStream">V</a>> stream, |
| <a href="Named.html" title="class in org.apache.kafka.streams.kstream">Named</a> named)</code></div> |
| <div class="col-last odd-row-color method-summary-table method-summary-table-tab2 method-summary-table-tab3"> |
| <div class="block">Merge this stream and the given stream into one larger stream.</div> |
| </div> |
| <div class="col-first even-row-color method-summary-table method-summary-table-tab2 method-summary-table-tab3"><code><VO,<wbr> |
| VR> <a href="KStream.html" title="interface in org.apache.kafka.streams.kstream">KStream</a><<a href="KStream.html" title="type parameter in KStream">K</a>,<wbr>VR></code></div> |
| <div class="col-second even-row-color method-summary-table method-summary-table-tab2 method-summary-table-tab3"><code><a href="#outerJoin(org.apache.kafka.streams.kstream.KStream,org.apache.kafka.streams.kstream.ValueJoiner,org.apache.kafka.streams.kstream.JoinWindows)" class="member-name-link">outerJoin</a><wbr>(<a href="KStream.html" title="interface in org.apache.kafka.streams.kstream">KStream</a><<a href="KStream.html" title="type parameter in KStream">K</a>,<wbr>VO> otherStream, |
| <a href="ValueJoiner.html" title="interface in org.apache.kafka.streams.kstream">ValueJoiner</a><? super <a href="KStream.html" title="type parameter in KStream">V</a>,<wbr>? super VO,<wbr>? extends VR> joiner, |
| <a href="JoinWindows.html" title="class in org.apache.kafka.streams.kstream">JoinWindows</a> windows)</code></div> |
| <div class="col-last even-row-color method-summary-table method-summary-table-tab2 method-summary-table-tab3"> |
| <div class="block">Join records of this stream with another <code>KStream</code>'s records using windowed outer equi join with default |
| serializers and deserializers.</div> |
| </div> |
| <div class="col-first odd-row-color method-summary-table method-summary-table-tab2 method-summary-table-tab3"><code><VO,<wbr> |
| VR> <a href="KStream.html" title="interface in org.apache.kafka.streams.kstream">KStream</a><<a href="KStream.html" title="type parameter in KStream">K</a>,<wbr>VR></code></div> |
| <div class="col-second odd-row-color method-summary-table method-summary-table-tab2 method-summary-table-tab3"><code><a href="#outerJoin(org.apache.kafka.streams.kstream.KStream,org.apache.kafka.streams.kstream.ValueJoiner,org.apache.kafka.streams.kstream.JoinWindows,org.apache.kafka.streams.kstream.StreamJoined)" class="member-name-link">outerJoin</a><wbr>(<a href="KStream.html" title="interface in org.apache.kafka.streams.kstream">KStream</a><<a href="KStream.html" title="type parameter in KStream">K</a>,<wbr>VO> otherStream, |
| <a href="ValueJoiner.html" title="interface in org.apache.kafka.streams.kstream">ValueJoiner</a><? super <a href="KStream.html" title="type parameter in KStream">V</a>,<wbr>? super VO,<wbr>? extends VR> joiner, |
| <a href="JoinWindows.html" title="class in org.apache.kafka.streams.kstream">JoinWindows</a> windows, |
| <a href="StreamJoined.html" title="class in org.apache.kafka.streams.kstream">StreamJoined</a><<a href="KStream.html" title="type parameter in KStream">K</a>,<wbr><a href="KStream.html" title="type parameter in KStream">V</a>,<wbr>VO> streamJoined)</code></div> |
| <div class="col-last odd-row-color method-summary-table method-summary-table-tab2 method-summary-table-tab3"> |
| <div class="block">Join records of this stream with another <code>KStream</code>'s records using windowed outer equi join using the |
| <a href="StreamJoined.html" title="class in org.apache.kafka.streams.kstream"><code>StreamJoined</code></a> instance for configuration of the <a href="../../common/serialization/Serde.html" title="interface in org.apache.kafka.common.serialization"><code>key serde</code></a>, <a href="../../common/serialization/Serde.html" title="interface in org.apache.kafka.common.serialization"><code>this stream's value |
| serde</code></a>, <a href="../../common/serialization/Serde.html" title="interface in org.apache.kafka.common.serialization"><code>the other stream's value serde</code></a>, and used state stores.</div> |
| </div> |
| <div class="col-first even-row-color method-summary-table method-summary-table-tab2 method-summary-table-tab3"><code><VO,<wbr> |
| VR> <a href="KStream.html" title="interface in org.apache.kafka.streams.kstream">KStream</a><<a href="KStream.html" title="type parameter in KStream">K</a>,<wbr>VR></code></div> |
| <div class="col-second even-row-color method-summary-table method-summary-table-tab2 method-summary-table-tab3"><code><a href="#outerJoin(org.apache.kafka.streams.kstream.KStream,org.apache.kafka.streams.kstream.ValueJoinerWithKey,org.apache.kafka.streams.kstream.JoinWindows)" class="member-name-link">outerJoin</a><wbr>(<a href="KStream.html" title="interface in org.apache.kafka.streams.kstream">KStream</a><<a href="KStream.html" title="type parameter in KStream">K</a>,<wbr>VO> otherStream, |
| <a href="ValueJoinerWithKey.html" title="interface in org.apache.kafka.streams.kstream">ValueJoinerWithKey</a><? super <a href="KStream.html" title="type parameter in KStream">K</a>,<wbr>? super <a href="KStream.html" title="type parameter in KStream">V</a>,<wbr>? super VO,<wbr>? extends VR> joiner, |
| <a href="JoinWindows.html" title="class in org.apache.kafka.streams.kstream">JoinWindows</a> windows)</code></div> |
| <div class="col-last even-row-color method-summary-table method-summary-table-tab2 method-summary-table-tab3"> |
| <div class="block">Join records of this stream with another <code>KStream</code>'s records using windowed outer equi join with default |
| serializers and deserializers.</div> |
| </div> |
| <div class="col-first odd-row-color method-summary-table method-summary-table-tab2 method-summary-table-tab3"><code><VO,<wbr> |
| VR> <a href="KStream.html" title="interface in org.apache.kafka.streams.kstream">KStream</a><<a href="KStream.html" title="type parameter in KStream">K</a>,<wbr>VR></code></div> |
| <div class="col-second odd-row-color method-summary-table method-summary-table-tab2 method-summary-table-tab3"><code><a href="#outerJoin(org.apache.kafka.streams.kstream.KStream,org.apache.kafka.streams.kstream.ValueJoinerWithKey,org.apache.kafka.streams.kstream.JoinWindows,org.apache.kafka.streams.kstream.StreamJoined)" class="member-name-link">outerJoin</a><wbr>(<a href="KStream.html" title="interface in org.apache.kafka.streams.kstream">KStream</a><<a href="KStream.html" title="type parameter in KStream">K</a>,<wbr>VO> otherStream, |
| <a href="ValueJoinerWithKey.html" title="interface in org.apache.kafka.streams.kstream">ValueJoinerWithKey</a><? super <a href="KStream.html" title="type parameter in KStream">K</a>,<wbr>? super <a href="KStream.html" title="type parameter in KStream">V</a>,<wbr>? super VO,<wbr>? extends VR> joiner, |
| <a href="JoinWindows.html" title="class in org.apache.kafka.streams.kstream">JoinWindows</a> windows, |
| <a href="StreamJoined.html" title="class in org.apache.kafka.streams.kstream">StreamJoined</a><<a href="KStream.html" title="type parameter in KStream">K</a>,<wbr><a href="KStream.html" title="type parameter in KStream">V</a>,<wbr>VO> streamJoined)</code></div> |
| <div class="col-last odd-row-color method-summary-table method-summary-table-tab2 method-summary-table-tab3"> |
| <div class="block">Join records of this stream with another <code>KStream</code>'s records using windowed outer equi join using the |
| <a href="StreamJoined.html" title="class in org.apache.kafka.streams.kstream"><code>StreamJoined</code></a> instance for configuration of the <a href="../../common/serialization/Serde.html" title="interface in org.apache.kafka.common.serialization"><code>key serde</code></a>, <a href="../../common/serialization/Serde.html" title="interface in org.apache.kafka.common.serialization"><code>this stream's value |
| serde</code></a>, <a href="../../common/serialization/Serde.html" title="interface in org.apache.kafka.common.serialization"><code>the other stream's value serde</code></a>, and used state stores.</div> |
| </div> |
| <div class="col-first even-row-color method-summary-table method-summary-table-tab2 method-summary-table-tab3"><code><a href="KStream.html" title="interface in org.apache.kafka.streams.kstream">KStream</a><<a href="KStream.html" title="type parameter in KStream">K</a>,<wbr><a href="KStream.html" title="type parameter in KStream">V</a>></code></div> |
| <div class="col-second even-row-color method-summary-table method-summary-table-tab2 method-summary-table-tab3"><code><a href="#peek(org.apache.kafka.streams.kstream.ForeachAction)" class="member-name-link">peek</a><wbr>(<a href="ForeachAction.html" title="interface in org.apache.kafka.streams.kstream">ForeachAction</a><? super <a href="KStream.html" title="type parameter in KStream">K</a>,<wbr>? super <a href="KStream.html" title="type parameter in KStream">V</a>> action)</code></div> |
| <div class="col-last even-row-color method-summary-table method-summary-table-tab2 method-summary-table-tab3"> |
| <div class="block">Perform an action on each record of <code>KStream</code>.</div> |
| </div> |
| <div class="col-first odd-row-color method-summary-table method-summary-table-tab2 method-summary-table-tab3"><code><a href="KStream.html" title="interface in org.apache.kafka.streams.kstream">KStream</a><<a href="KStream.html" title="type parameter in KStream">K</a>,<wbr><a href="KStream.html" title="type parameter in KStream">V</a>></code></div> |
| <div class="col-second odd-row-color method-summary-table method-summary-table-tab2 method-summary-table-tab3"><code><a href="#peek(org.apache.kafka.streams.kstream.ForeachAction,org.apache.kafka.streams.kstream.Named)" class="member-name-link">peek</a><wbr>(<a href="ForeachAction.html" title="interface in org.apache.kafka.streams.kstream">ForeachAction</a><? super <a href="KStream.html" title="type parameter in KStream">K</a>,<wbr>? super <a href="KStream.html" title="type parameter in KStream">V</a>> action, |
| <a href="Named.html" title="class in org.apache.kafka.streams.kstream">Named</a> named)</code></div> |
| <div class="col-last odd-row-color method-summary-table method-summary-table-tab2 method-summary-table-tab3"> |
| <div class="block">Perform an action on each record of <code>KStream</code>.</div> |
| </div> |
| <div class="col-first even-row-color method-summary-table method-summary-table-tab2 method-summary-table-tab3"><code>void</code></div> |
| <div class="col-second even-row-color method-summary-table method-summary-table-tab2 method-summary-table-tab3"><code><a href="#print(org.apache.kafka.streams.kstream.Printed)" class="member-name-link">print</a><wbr>(<a href="Printed.html" title="class in org.apache.kafka.streams.kstream">Printed</a><<a href="KStream.html" title="type parameter in KStream">K</a>,<wbr><a href="KStream.html" title="type parameter in KStream">V</a>> printed)</code></div> |
| <div class="col-last even-row-color method-summary-table method-summary-table-tab2 method-summary-table-tab3"> |
| <div class="block">Print the records of this KStream using the options provided by <a href="Printed.html" title="class in org.apache.kafka.streams.kstream"><code>Printed</code></a> |
| Note that this is mainly for debugging/testing purposes, and it will try to flush on each record print.</div> |
| </div> |
| <div class="col-first odd-row-color method-summary-table method-summary-table-tab2 method-summary-table-tab3"><code>void</code></div> |
| <div class="col-second odd-row-color method-summary-table method-summary-table-tab2 method-summary-table-tab3"><code><a href="#process(org.apache.kafka.streams.processor.api.ProcessorSupplier,java.lang.String...)" class="member-name-link">process</a><wbr>(<a href="../processor/api/ProcessorSupplier.html" title="interface in org.apache.kafka.streams.processor.api">ProcessorSupplier</a><? super <a href="KStream.html" title="type parameter in KStream">K</a>,<wbr>? super <a href="KStream.html" title="type parameter in KStream">V</a>,<wbr><a href="https://docs.oracle.com/en/java/javase/17/docs/api/java.base/java/lang/Void.html" title="class or interface in java.lang" class="external-link">Void</a>,<wbr><a href="https://docs.oracle.com/en/java/javase/17/docs/api/java.base/java/lang/Void.html" title="class or interface in java.lang" class="external-link">Void</a>> processorSupplier, |
| <a href="https://docs.oracle.com/en/java/javase/17/docs/api/java.base/java/lang/String.html" title="class or interface in java.lang" class="external-link">String</a>... stateStoreNames)</code></div> |
| <div class="col-last odd-row-color method-summary-table method-summary-table-tab2 method-summary-table-tab3"> |
| <div class="block">Process all records in this stream, one record at a time, by applying a <a href="../processor/api/Processor.html" title="interface in org.apache.kafka.streams.processor.api"><code>Processor</code></a> (provided by the given |
| <a href="../processor/api/ProcessorSupplier.html" title="interface in org.apache.kafka.streams.processor.api"><code>ProcessorSupplier</code></a>).</div> |
| </div> |
| <div class="col-first even-row-color method-summary-table method-summary-table-tab2 method-summary-table-tab3"><code>void</code></div> |
| <div class="col-second even-row-color method-summary-table method-summary-table-tab2 method-summary-table-tab3"><code><a href="#process(org.apache.kafka.streams.processor.api.ProcessorSupplier,org.apache.kafka.streams.kstream.Named,java.lang.String...)" class="member-name-link">process</a><wbr>(<a href="../processor/api/ProcessorSupplier.html" title="interface in org.apache.kafka.streams.processor.api">ProcessorSupplier</a><? super <a href="KStream.html" title="type parameter in KStream">K</a>,<wbr>? super <a href="KStream.html" title="type parameter in KStream">V</a>,<wbr><a href="https://docs.oracle.com/en/java/javase/17/docs/api/java.base/java/lang/Void.html" title="class or interface in java.lang" class="external-link">Void</a>,<wbr><a href="https://docs.oracle.com/en/java/javase/17/docs/api/java.base/java/lang/Void.html" title="class or interface in java.lang" class="external-link">Void</a>> processorSupplier, |
| <a href="Named.html" title="class in org.apache.kafka.streams.kstream">Named</a> named, |
| <a href="https://docs.oracle.com/en/java/javase/17/docs/api/java.base/java/lang/String.html" title="class or interface in java.lang" class="external-link">String</a>... stateStoreNames)</code></div> |
| <div class="col-last even-row-color method-summary-table method-summary-table-tab2 method-summary-table-tab3"> |
| <div class="block">Process all records in this stream, one record at a time, by applying a <a href="../processor/api/Processor.html" title="interface in org.apache.kafka.streams.processor.api"><code>Processor</code></a> (provided by the given |
| <a href="../processor/api/ProcessorSupplier.html" title="interface in org.apache.kafka.streams.processor.api"><code>ProcessorSupplier</code></a>).</div> |
| </div> |
| <div class="col-first odd-row-color method-summary-table method-summary-table-tab2 method-summary-table-tab3 method-summary-table-tab6"><code>void</code></div> |
| <div class="col-second odd-row-color method-summary-table method-summary-table-tab2 method-summary-table-tab3 method-summary-table-tab6"><code><a href="#process(org.apache.kafka.streams.processor.ProcessorSupplier,java.lang.String...)" class="member-name-link">process</a><wbr>(<a href="../processor/ProcessorSupplier.html" title="interface in org.apache.kafka.streams.processor">ProcessorSupplier</a><? super <a href="KStream.html" title="type parameter in KStream">K</a>,<wbr>? super <a href="KStream.html" title="type parameter in KStream">V</a>> processorSupplier, |
| <a href="https://docs.oracle.com/en/java/javase/17/docs/api/java.base/java/lang/String.html" title="class or interface in java.lang" class="external-link">String</a>... stateStoreNames)</code></div> |
| <div class="col-last odd-row-color method-summary-table method-summary-table-tab2 method-summary-table-tab3 method-summary-table-tab6"> |
| <div class="block"><span class="deprecated-label">Deprecated.</span> |
| <div class="deprecation-comment">Since 3.0.</div> |
| </div> |
| </div> |
| <div class="col-first even-row-color method-summary-table method-summary-table-tab2 method-summary-table-tab3 method-summary-table-tab6"><code>void</code></div> |
| <div class="col-second even-row-color method-summary-table method-summary-table-tab2 method-summary-table-tab3 method-summary-table-tab6"><code><a href="#process(org.apache.kafka.streams.processor.ProcessorSupplier,org.apache.kafka.streams.kstream.Named,java.lang.String...)" class="member-name-link">process</a><wbr>(<a href="../processor/ProcessorSupplier.html" title="interface in org.apache.kafka.streams.processor">ProcessorSupplier</a><? super <a href="KStream.html" title="type parameter in KStream">K</a>,<wbr>? super <a href="KStream.html" title="type parameter in KStream">V</a>> processorSupplier, |
| <a href="Named.html" title="class in org.apache.kafka.streams.kstream">Named</a> named, |
| <a href="https://docs.oracle.com/en/java/javase/17/docs/api/java.base/java/lang/String.html" title="class or interface in java.lang" class="external-link">String</a>... stateStoreNames)</code></div> |
| <div class="col-last even-row-color method-summary-table method-summary-table-tab2 method-summary-table-tab3 method-summary-table-tab6"> |
| <div class="block"><span class="deprecated-label">Deprecated.</span> |
| <div class="deprecation-comment">Since 3.0.</div> |
| </div> |
| </div> |
| <div class="col-first odd-row-color method-summary-table method-summary-table-tab2 method-summary-table-tab3"><code><a href="KStream.html" title="interface in org.apache.kafka.streams.kstream">KStream</a><<a href="KStream.html" title="type parameter in KStream">K</a>,<wbr><a href="KStream.html" title="type parameter in KStream">V</a>></code></div> |
| <div class="col-second odd-row-color method-summary-table method-summary-table-tab2 method-summary-table-tab3"><code><a href="#repartition()" class="member-name-link">repartition</a>()</code></div> |
| <div class="col-last odd-row-color method-summary-table method-summary-table-tab2 method-summary-table-tab3"> |
| <div class="block">Materialize this stream to an auto-generated repartition topic and create a new <code>KStream</code> |
| from the auto-generated topic using default serializers, deserializers, and producer's <code>DefaultPartitioner</code>.</div> |
| </div> |
| <div class="col-first even-row-color method-summary-table method-summary-table-tab2 method-summary-table-tab3"><code><a href="KStream.html" title="interface in org.apache.kafka.streams.kstream">KStream</a><<a href="KStream.html" title="type parameter in KStream">K</a>,<wbr><a href="KStream.html" title="type parameter in KStream">V</a>></code></div> |
| <div class="col-second even-row-color method-summary-table method-summary-table-tab2 method-summary-table-tab3"><code><a href="#repartition(org.apache.kafka.streams.kstream.Repartitioned)" class="member-name-link">repartition</a><wbr>(<a href="Repartitioned.html" title="class in org.apache.kafka.streams.kstream">Repartitioned</a><<a href="KStream.html" title="type parameter in KStream">K</a>,<wbr><a href="KStream.html" title="type parameter in KStream">V</a>> repartitioned)</code></div> |
| <div class="col-last even-row-color method-summary-table method-summary-table-tab2 method-summary-table-tab3"> |
| <div class="block">Materialize this stream to an auto-generated repartition topic and create a new <code>KStream</code> |
| from the auto-generated topic using <a href="../../common/serialization/Serde.html" title="interface in org.apache.kafka.common.serialization"><code>key serde</code></a>, <a href="../../common/serialization/Serde.html" title="interface in org.apache.kafka.common.serialization"><code>value serde</code></a>, <a href="../processor/StreamPartitioner.html" title="interface in org.apache.kafka.streams.processor"><code>StreamPartitioner</code></a>, |
| number of partitions, and topic name part as defined by <a href="Repartitioned.html" title="class in org.apache.kafka.streams.kstream"><code>Repartitioned</code></a>.</div> |
| </div> |
| <div class="col-first odd-row-color method-summary-table method-summary-table-tab2 method-summary-table-tab3"><code><KR> <a href="KStream.html" title="interface in org.apache.kafka.streams.kstream">KStream</a><KR,<wbr><a href="KStream.html" title="type parameter in KStream">V</a>></code></div> |
| <div class="col-second odd-row-color method-summary-table method-summary-table-tab2 method-summary-table-tab3"><code><a href="#selectKey(org.apache.kafka.streams.kstream.KeyValueMapper)" class="member-name-link">selectKey</a><wbr>(<a href="KeyValueMapper.html" title="interface in org.apache.kafka.streams.kstream">KeyValueMapper</a><? super <a href="KStream.html" title="type parameter in KStream">K</a>,<wbr>? super <a href="KStream.html" title="type parameter in KStream">V</a>,<wbr>? extends KR> mapper)</code></div> |
| <div class="col-last odd-row-color method-summary-table method-summary-table-tab2 method-summary-table-tab3"> |
| <div class="block">Set a new key (with possibly new type) for each input record.</div> |
| </div> |
| <div class="col-first even-row-color method-summary-table method-summary-table-tab2 method-summary-table-tab3"><code><KR> <a href="KStream.html" title="interface in org.apache.kafka.streams.kstream">KStream</a><KR,<wbr><a href="KStream.html" title="type parameter in KStream">V</a>></code></div> |
| <div class="col-second even-row-color method-summary-table method-summary-table-tab2 method-summary-table-tab3"><code><a href="#selectKey(org.apache.kafka.streams.kstream.KeyValueMapper,org.apache.kafka.streams.kstream.Named)" class="member-name-link">selectKey</a><wbr>(<a href="KeyValueMapper.html" title="interface in org.apache.kafka.streams.kstream">KeyValueMapper</a><? super <a href="KStream.html" title="type parameter in KStream">K</a>,<wbr>? super <a href="KStream.html" title="type parameter in KStream">V</a>,<wbr>? extends KR> mapper, |
| <a href="Named.html" title="class in org.apache.kafka.streams.kstream">Named</a> named)</code></div> |
| <div class="col-last even-row-color method-summary-table method-summary-table-tab2 method-summary-table-tab3"> |
| <div class="block">Set a new key (with possibly new type) for each input record.</div> |
| </div> |
| <div class="col-first odd-row-color method-summary-table method-summary-table-tab2 method-summary-table-tab3"><code><a href="BranchedKStream.html" title="interface in org.apache.kafka.streams.kstream">BranchedKStream</a><<a href="KStream.html" title="type parameter in KStream">K</a>,<wbr><a href="KStream.html" title="type parameter in KStream">V</a>></code></div> |
| <div class="col-second odd-row-color method-summary-table method-summary-table-tab2 method-summary-table-tab3"><code><a href="#split()" class="member-name-link">split</a>()</code></div> |
| <div class="col-last odd-row-color method-summary-table method-summary-table-tab2 method-summary-table-tab3"> |
| <div class="block">Split this stream into different branches.</div> |
| </div> |
| <div class="col-first even-row-color method-summary-table method-summary-table-tab2 method-summary-table-tab3"><code><a href="BranchedKStream.html" title="interface in org.apache.kafka.streams.kstream">BranchedKStream</a><<a href="KStream.html" title="type parameter in KStream">K</a>,<wbr><a href="KStream.html" title="type parameter in KStream">V</a>></code></div> |
| <div class="col-second even-row-color method-summary-table method-summary-table-tab2 method-summary-table-tab3"><code><a href="#split(org.apache.kafka.streams.kstream.Named)" class="member-name-link">split</a><wbr>(<a href="Named.html" title="class in org.apache.kafka.streams.kstream">Named</a> named)</code></div> |
| <div class="col-last even-row-color method-summary-table method-summary-table-tab2 method-summary-table-tab3"> |
| <div class="block">Split this stream into different branches.</div> |
| </div> |
| <div class="col-first odd-row-color method-summary-table method-summary-table-tab2 method-summary-table-tab3 method-summary-table-tab6"><code><a href="KStream.html" title="interface in org.apache.kafka.streams.kstream">KStream</a><<a href="KStream.html" title="type parameter in KStream">K</a>,<wbr><a href="KStream.html" title="type parameter in KStream">V</a>></code></div> |
| <div class="col-second odd-row-color method-summary-table method-summary-table-tab2 method-summary-table-tab3 method-summary-table-tab6"><code><a href="#through(java.lang.String)" class="member-name-link">through</a><wbr>(<a href="https://docs.oracle.com/en/java/javase/17/docs/api/java.base/java/lang/String.html" title="class or interface in java.lang" class="external-link">String</a> topic)</code></div> |
| <div class="col-last odd-row-color method-summary-table method-summary-table-tab2 method-summary-table-tab3 method-summary-table-tab6"> |
| <div class="block"><span class="deprecated-label">Deprecated.</span> |
| <div class="deprecation-comment">since 2.6; use <a href="#repartition()"><code>repartition()</code></a> instead</div> |
| </div> |
| </div> |
| <div class="col-first even-row-color method-summary-table method-summary-table-tab2 method-summary-table-tab3 method-summary-table-tab6"><code><a href="KStream.html" title="interface in org.apache.kafka.streams.kstream">KStream</a><<a href="KStream.html" title="type parameter in KStream">K</a>,<wbr><a href="KStream.html" title="type parameter in KStream">V</a>></code></div> |
| <div class="col-second even-row-color method-summary-table method-summary-table-tab2 method-summary-table-tab3 method-summary-table-tab6"><code><a href="#through(java.lang.String,org.apache.kafka.streams.kstream.Produced)" class="member-name-link">through</a><wbr>(<a href="https://docs.oracle.com/en/java/javase/17/docs/api/java.base/java/lang/String.html" title="class or interface in java.lang" class="external-link">String</a> topic, |
| <a href="Produced.html" title="class in org.apache.kafka.streams.kstream">Produced</a><<a href="KStream.html" title="type parameter in KStream">K</a>,<wbr><a href="KStream.html" title="type parameter in KStream">V</a>> produced)</code></div> |
| <div class="col-last even-row-color method-summary-table method-summary-table-tab2 method-summary-table-tab3 method-summary-table-tab6"> |
| <div class="block"><span class="deprecated-label">Deprecated.</span> |
| <div class="deprecation-comment">since 2.6; use <a href="#repartition(org.apache.kafka.streams.kstream.Repartitioned)"><code>repartition(Repartitioned)</code></a> instead</div> |
| </div> |
| </div> |
| <div class="col-first odd-row-color method-summary-table method-summary-table-tab2 method-summary-table-tab3"><code>void</code></div> |
| <div class="col-second odd-row-color method-summary-table method-summary-table-tab2 method-summary-table-tab3"><code><a href="#to(java.lang.String)" class="member-name-link">to</a><wbr>(<a href="https://docs.oracle.com/en/java/javase/17/docs/api/java.base/java/lang/String.html" title="class or interface in java.lang" class="external-link">String</a> topic)</code></div> |
| <div class="col-last odd-row-color method-summary-table method-summary-table-tab2 method-summary-table-tab3"> |
| <div class="block">Materialize this stream to a topic using default serializers specified in the config and producer's |
| <code>DefaultPartitioner</code>.</div> |
| </div> |
| <div class="col-first even-row-color method-summary-table method-summary-table-tab2 method-summary-table-tab3"><code>void</code></div> |
| <div class="col-second even-row-color method-summary-table method-summary-table-tab2 method-summary-table-tab3"><code><a href="#to(java.lang.String,org.apache.kafka.streams.kstream.Produced)" class="member-name-link">to</a><wbr>(<a href="https://docs.oracle.com/en/java/javase/17/docs/api/java.base/java/lang/String.html" title="class or interface in java.lang" class="external-link">String</a> topic, |
| <a href="Produced.html" title="class in org.apache.kafka.streams.kstream">Produced</a><<a href="KStream.html" title="type parameter in KStream">K</a>,<wbr><a href="KStream.html" title="type parameter in KStream">V</a>> produced)</code></div> |
| <div class="col-last even-row-color method-summary-table method-summary-table-tab2 method-summary-table-tab3"> |
| <div class="block">Materialize this stream to a topic using the provided <a href="Produced.html" title="class in org.apache.kafka.streams.kstream"><code>Produced</code></a> instance.</div> |
| </div> |
| <div class="col-first odd-row-color method-summary-table method-summary-table-tab2 method-summary-table-tab3"><code>void</code></div> |
| <div class="col-second odd-row-color method-summary-table method-summary-table-tab2 method-summary-table-tab3"><code><a href="#to(org.apache.kafka.streams.processor.TopicNameExtractor)" class="member-name-link">to</a><wbr>(<a href="../processor/TopicNameExtractor.html" title="interface in org.apache.kafka.streams.processor">TopicNameExtractor</a><<a href="KStream.html" title="type parameter in KStream">K</a>,<wbr><a href="KStream.html" title="type parameter in KStream">V</a>> topicExtractor)</code></div> |
| <div class="col-last odd-row-color method-summary-table method-summary-table-tab2 method-summary-table-tab3"> |
| <div class="block">Dynamically materialize this stream to topics using default serializers specified in the config and producer's |
| <code>DefaultPartitioner</code>.</div> |
| </div> |
| <div class="col-first even-row-color method-summary-table method-summary-table-tab2 method-summary-table-tab3"><code>void</code></div> |
| <div class="col-second even-row-color method-summary-table method-summary-table-tab2 method-summary-table-tab3"><code><a href="#to(org.apache.kafka.streams.processor.TopicNameExtractor,org.apache.kafka.streams.kstream.Produced)" class="member-name-link">to</a><wbr>(<a href="../processor/TopicNameExtractor.html" title="interface in org.apache.kafka.streams.processor">TopicNameExtractor</a><<a href="KStream.html" title="type parameter in KStream">K</a>,<wbr><a href="KStream.html" title="type parameter in KStream">V</a>> topicExtractor, |
| <a href="Produced.html" title="class in org.apache.kafka.streams.kstream">Produced</a><<a href="KStream.html" title="type parameter in KStream">K</a>,<wbr><a href="KStream.html" title="type parameter in KStream">V</a>> produced)</code></div> |
| <div class="col-last even-row-color method-summary-table method-summary-table-tab2 method-summary-table-tab3"> |
| <div class="block">Dynamically materialize this stream to topics using the provided <a href="Produced.html" title="class in org.apache.kafka.streams.kstream"><code>Produced</code></a> instance.</div> |
| </div> |
| <div class="col-first odd-row-color method-summary-table method-summary-table-tab2 method-summary-table-tab3"><code><a href="KTable.html" title="interface in org.apache.kafka.streams.kstream">KTable</a><<a href="KStream.html" title="type parameter in KStream">K</a>,<wbr><a href="KStream.html" title="type parameter in KStream">V</a>></code></div> |
| <div class="col-second odd-row-color method-summary-table method-summary-table-tab2 method-summary-table-tab3"><code><a href="#toTable()" class="member-name-link">toTable</a>()</code></div> |
| <div class="col-last odd-row-color method-summary-table method-summary-table-tab2 method-summary-table-tab3"> |
| <div class="block">Convert this stream to a <a href="KTable.html" title="interface in org.apache.kafka.streams.kstream"><code>KTable</code></a>.</div> |
| </div> |
| <div class="col-first even-row-color method-summary-table method-summary-table-tab2 method-summary-table-tab3"><code><a href="KTable.html" title="interface in org.apache.kafka.streams.kstream">KTable</a><<a href="KStream.html" title="type parameter in KStream">K</a>,<wbr><a href="KStream.html" title="type parameter in KStream">V</a>></code></div> |
| <div class="col-second even-row-color method-summary-table method-summary-table-tab2 method-summary-table-tab3"><code><a href="#toTable(org.apache.kafka.streams.kstream.Materialized)" class="member-name-link">toTable</a><wbr>(<a href="Materialized.html" title="class in org.apache.kafka.streams.kstream">Materialized</a><<a href="KStream.html" title="type parameter in KStream">K</a>,<wbr><a href="KStream.html" title="type parameter in KStream">V</a>,<wbr><a href="../state/KeyValueStore.html" title="interface in org.apache.kafka.streams.state">KeyValueStore</a><org.apache.kafka.common.utils.Bytes,<wbr>byte[]>> materialized)</code></div> |
| <div class="col-last even-row-color method-summary-table method-summary-table-tab2 method-summary-table-tab3"> |
| <div class="block">Convert this stream to a <a href="KTable.html" title="interface in org.apache.kafka.streams.kstream"><code>KTable</code></a>.</div> |
| </div> |
| <div class="col-first odd-row-color method-summary-table method-summary-table-tab2 method-summary-table-tab3"><code><a href="KTable.html" title="interface in org.apache.kafka.streams.kstream">KTable</a><<a href="KStream.html" title="type parameter in KStream">K</a>,<wbr><a href="KStream.html" title="type parameter in KStream">V</a>></code></div> |
| <div class="col-second odd-row-color method-summary-table method-summary-table-tab2 method-summary-table-tab3"><code><a href="#toTable(org.apache.kafka.streams.kstream.Named)" class="member-name-link">toTable</a><wbr>(<a href="Named.html" title="class in org.apache.kafka.streams.kstream">Named</a> named)</code></div> |
| <div class="col-last odd-row-color method-summary-table method-summary-table-tab2 method-summary-table-tab3"> |
| <div class="block">Convert this stream to a <a href="KTable.html" title="interface in org.apache.kafka.streams.kstream"><code>KTable</code></a>.</div> |
| </div> |
| <div class="col-first even-row-color method-summary-table method-summary-table-tab2 method-summary-table-tab3"><code><a href="KTable.html" title="interface in org.apache.kafka.streams.kstream">KTable</a><<a href="KStream.html" title="type parameter in KStream">K</a>,<wbr><a href="KStream.html" title="type parameter in KStream">V</a>></code></div> |
| <div class="col-second even-row-color method-summary-table method-summary-table-tab2 method-summary-table-tab3"><code><a href="#toTable(org.apache.kafka.streams.kstream.Named,org.apache.kafka.streams.kstream.Materialized)" class="member-name-link">toTable</a><wbr>(<a href="Named.html" title="class in org.apache.kafka.streams.kstream">Named</a> named, |
| <a href="Materialized.html" title="class in org.apache.kafka.streams.kstream">Materialized</a><<a href="KStream.html" title="type parameter in KStream">K</a>,<wbr><a href="KStream.html" title="type parameter in KStream">V</a>,<wbr><a href="../state/KeyValueStore.html" title="interface in org.apache.kafka.streams.state">KeyValueStore</a><org.apache.kafka.common.utils.Bytes,<wbr>byte[]>> materialized)</code></div> |
| <div class="col-last even-row-color method-summary-table method-summary-table-tab2 method-summary-table-tab3"> |
| <div class="block">Convert this stream to a <a href="KTable.html" title="interface in org.apache.kafka.streams.kstream"><code>KTable</code></a>.</div> |
| </div> |
| <div class="col-first odd-row-color method-summary-table method-summary-table-tab2 method-summary-table-tab3"><code><K1,<wbr> |
| V1> <a href="KStream.html" title="interface in org.apache.kafka.streams.kstream">KStream</a><K1,<wbr>V1></code></div> |
| <div class="col-second odd-row-color method-summary-table method-summary-table-tab2 method-summary-table-tab3"><code><a href="#transform(org.apache.kafka.streams.kstream.TransformerSupplier,java.lang.String...)" class="member-name-link">transform</a><wbr>(<a href="TransformerSupplier.html" title="interface in org.apache.kafka.streams.kstream">TransformerSupplier</a><? super <a href="KStream.html" title="type parameter in KStream">K</a>,<wbr>? super <a href="KStream.html" title="type parameter in KStream">V</a>,<wbr><a href="../KeyValue.html" title="class in org.apache.kafka.streams">KeyValue</a><K1,<wbr>V1>> transformerSupplier, |
| <a href="https://docs.oracle.com/en/java/javase/17/docs/api/java.base/java/lang/String.html" title="class or interface in java.lang" class="external-link">String</a>... stateStoreNames)</code></div> |
| <div class="col-last odd-row-color method-summary-table method-summary-table-tab2 method-summary-table-tab3"> |
| <div class="block">Transform each record of the input stream into zero or one record in the output stream (both key and value type |
| can be altered arbitrarily).</div> |
| </div> |
| <div class="col-first even-row-color method-summary-table method-summary-table-tab2 method-summary-table-tab3"><code><K1,<wbr> |
| V1> <a href="KStream.html" title="interface in org.apache.kafka.streams.kstream">KStream</a><K1,<wbr>V1></code></div> |
| <div class="col-second even-row-color method-summary-table method-summary-table-tab2 method-summary-table-tab3"><code><a href="#transform(org.apache.kafka.streams.kstream.TransformerSupplier,org.apache.kafka.streams.kstream.Named,java.lang.String...)" class="member-name-link">transform</a><wbr>(<a href="TransformerSupplier.html" title="interface in org.apache.kafka.streams.kstream">TransformerSupplier</a><? super <a href="KStream.html" title="type parameter in KStream">K</a>,<wbr>? super <a href="KStream.html" title="type parameter in KStream">V</a>,<wbr><a href="../KeyValue.html" title="class in org.apache.kafka.streams">KeyValue</a><K1,<wbr>V1>> transformerSupplier, |
| <a href="Named.html" title="class in org.apache.kafka.streams.kstream">Named</a> named, |
| <a href="https://docs.oracle.com/en/java/javase/17/docs/api/java.base/java/lang/String.html" title="class or interface in java.lang" class="external-link">String</a>... stateStoreNames)</code></div> |
| <div class="col-last even-row-color method-summary-table method-summary-table-tab2 method-summary-table-tab3"> |
| <div class="block">Transform each record of the input stream into zero or one record in the output stream (both key and value type |
| can be altered arbitrarily).</div> |
| </div> |
| <div class="col-first odd-row-color method-summary-table method-summary-table-tab2 method-summary-table-tab3"><code><VR> <a href="KStream.html" title="interface in org.apache.kafka.streams.kstream">KStream</a><<a href="KStream.html" title="type parameter in KStream">K</a>,<wbr>VR></code></div> |
| <div class="col-second odd-row-color method-summary-table method-summary-table-tab2 method-summary-table-tab3"><code><a href="#transformValues(org.apache.kafka.streams.kstream.ValueTransformerSupplier,java.lang.String...)" class="member-name-link">transformValues</a><wbr>(<a href="ValueTransformerSupplier.html" title="interface in org.apache.kafka.streams.kstream">ValueTransformerSupplier</a><? super <a href="KStream.html" title="type parameter in KStream">V</a>,<wbr>? extends VR> valueTransformerSupplier, |
| <a href="https://docs.oracle.com/en/java/javase/17/docs/api/java.base/java/lang/String.html" title="class or interface in java.lang" class="external-link">String</a>... stateStoreNames)</code></div> |
| <div class="col-last odd-row-color method-summary-table method-summary-table-tab2 method-summary-table-tab3"> |
| <div class="block">Transform the value of each input record into a new value (with possibly a new type) of the output record.</div> |
| </div> |
| <div class="col-first even-row-color method-summary-table method-summary-table-tab2 method-summary-table-tab3"><code><VR> <a href="KStream.html" title="interface in org.apache.kafka.streams.kstream">KStream</a><<a href="KStream.html" title="type parameter in KStream">K</a>,<wbr>VR></code></div> |
| <div class="col-second even-row-color method-summary-table method-summary-table-tab2 method-summary-table-tab3"><code><a href="#transformValues(org.apache.kafka.streams.kstream.ValueTransformerSupplier,org.apache.kafka.streams.kstream.Named,java.lang.String...)" class="member-name-link">transformValues</a><wbr>(<a href="ValueTransformerSupplier.html" title="interface in org.apache.kafka.streams.kstream">ValueTransformerSupplier</a><? super <a href="KStream.html" title="type parameter in KStream">V</a>,<wbr>? extends VR> valueTransformerSupplier, |
| <a href="Named.html" title="class in org.apache.kafka.streams.kstream">Named</a> named, |
| <a href="https://docs.oracle.com/en/java/javase/17/docs/api/java.base/java/lang/String.html" title="class or interface in java.lang" class="external-link">String</a>... stateStoreNames)</code></div> |
| <div class="col-last even-row-color method-summary-table method-summary-table-tab2 method-summary-table-tab3"> |
| <div class="block">Transform the value of each input record into a new value (with possibly a new type) of the output record.</div> |
| </div> |
| <div class="col-first odd-row-color method-summary-table method-summary-table-tab2 method-summary-table-tab3"><code><VR> <a href="KStream.html" title="interface in org.apache.kafka.streams.kstream">KStream</a><<a href="KStream.html" title="type parameter in KStream">K</a>,<wbr>VR></code></div> |
| <div class="col-second odd-row-color method-summary-table method-summary-table-tab2 method-summary-table-tab3"><code><a href="#transformValues(org.apache.kafka.streams.kstream.ValueTransformerWithKeySupplier,java.lang.String...)" class="member-name-link">transformValues</a><wbr>(<a href="ValueTransformerWithKeySupplier.html" title="interface in org.apache.kafka.streams.kstream">ValueTransformerWithKeySupplier</a><? super <a href="KStream.html" title="type parameter in KStream">K</a>,<wbr>? super <a href="KStream.html" title="type parameter in KStream">V</a>,<wbr>? extends VR> valueTransformerSupplier, |
| <a href="https://docs.oracle.com/en/java/javase/17/docs/api/java.base/java/lang/String.html" title="class or interface in java.lang" class="external-link">String</a>... stateStoreNames)</code></div> |
| <div class="col-last odd-row-color method-summary-table method-summary-table-tab2 method-summary-table-tab3"> |
| <div class="block">Transform the value of each input record into a new value (with possibly a new type) of the output record.</div> |
| </div> |
| <div class="col-first even-row-color method-summary-table method-summary-table-tab2 method-summary-table-tab3"><code><VR> <a href="KStream.html" title="interface in org.apache.kafka.streams.kstream">KStream</a><<a href="KStream.html" title="type parameter in KStream">K</a>,<wbr>VR></code></div> |
| <div class="col-second even-row-color method-summary-table method-summary-table-tab2 method-summary-table-tab3"><code><a href="#transformValues(org.apache.kafka.streams.kstream.ValueTransformerWithKeySupplier,org.apache.kafka.streams.kstream.Named,java.lang.String...)" class="member-name-link">transformValues</a><wbr>(<a href="ValueTransformerWithKeySupplier.html" title="interface in org.apache.kafka.streams.kstream">ValueTransformerWithKeySupplier</a><? super <a href="KStream.html" title="type parameter in KStream">K</a>,<wbr>? super <a href="KStream.html" title="type parameter in KStream">V</a>,<wbr>? extends VR> valueTransformerSupplier, |
| <a href="Named.html" title="class in org.apache.kafka.streams.kstream">Named</a> named, |
| <a href="https://docs.oracle.com/en/java/javase/17/docs/api/java.base/java/lang/String.html" title="class or interface in java.lang" class="external-link">String</a>... stateStoreNames)</code></div> |
| <div class="col-last even-row-color method-summary-table method-summary-table-tab2 method-summary-table-tab3"> |
| <div class="block">Transform the value of each input record into a new value (with possibly a new type) of the output record.</div> |
| </div> |
| </div> |
| </div> |
| </div> |
| </section> |
| </li> |
| </ul> |
| </section> |
| <section class="details"> |
| <ul class="details-list"> |
| <!-- ============ METHOD DETAIL ========== --> |
| <li> |
| <section class="method-details" id="method-detail"> |
| <h2>Method Details</h2> |
| <ul class="member-list"> |
| <li> |
| <section class="detail" id="filter(org.apache.kafka.streams.kstream.Predicate)"> |
| <h3>filter</h3> |
| <div class="member-signature"><span class="return-type"><a href="KStream.html" title="interface in org.apache.kafka.streams.kstream">KStream</a><<a href="KStream.html" title="type parameter in KStream">K</a>,<wbr><a href="KStream.html" title="type parameter in KStream">V</a>></span> <span class="element-name">filter</span><wbr><span class="parameters">(<a href="Predicate.html" title="interface in org.apache.kafka.streams.kstream">Predicate</a><? super <a href="KStream.html" title="type parameter in KStream">K</a>,<wbr>? super <a href="KStream.html" title="type parameter in KStream">V</a>> predicate)</span></div> |
| <div class="block">Create a new <code>KStream</code> that consists of all records of this stream which satisfy the given predicate. |
| All records that do not satisfy the predicate are dropped. |
| This is a stateless record-by-record operation.</div> |
| <dl class="notes"> |
| <dt>Parameters:</dt> |
| <dd><code>predicate</code> - a filter <a href="Predicate.html" title="interface in org.apache.kafka.streams.kstream"><code>Predicate</code></a> that is applied to each record</dd> |
| <dt>Returns:</dt> |
| <dd>a <code>KStream</code> that contains only those records that satisfy the given predicate</dd> |
| <dt>See Also:</dt> |
| <dd> |
| <ul class="see-list"> |
| <li><a href="#filterNot(org.apache.kafka.streams.kstream.Predicate)"><code>filterNot(Predicate)</code></a></li> |
| </ul> |
| </dd> |
| </dl> |
| </section> |
| </li> |
| <li> |
| <section class="detail" id="filter(org.apache.kafka.streams.kstream.Predicate,org.apache.kafka.streams.kstream.Named)"> |
| <h3>filter</h3> |
| <div class="member-signature"><span class="return-type"><a href="KStream.html" title="interface in org.apache.kafka.streams.kstream">KStream</a><<a href="KStream.html" title="type parameter in KStream">K</a>,<wbr><a href="KStream.html" title="type parameter in KStream">V</a>></span> <span class="element-name">filter</span><wbr><span class="parameters">(<a href="Predicate.html" title="interface in org.apache.kafka.streams.kstream">Predicate</a><? super <a href="KStream.html" title="type parameter in KStream">K</a>,<wbr>? super <a href="KStream.html" title="type parameter in KStream">V</a>> predicate, |
| <a href="Named.html" title="class in org.apache.kafka.streams.kstream">Named</a> named)</span></div> |
| <div class="block">Create a new <code>KStream</code> that consists of all records of this stream which satisfy the given predicate. |
| All records that do not satisfy the predicate are dropped. |
| This is a stateless record-by-record operation.</div> |
| <dl class="notes"> |
| <dt>Parameters:</dt> |
| <dd><code>predicate</code> - a filter <a href="Predicate.html" title="interface in org.apache.kafka.streams.kstream"><code>Predicate</code></a> that is applied to each record</dd> |
| <dd><code>named</code> - a <a href="Named.html" title="class in org.apache.kafka.streams.kstream"><code>Named</code></a> config used to name the processor in the topology</dd> |
| <dt>Returns:</dt> |
| <dd>a <code>KStream</code> that contains only those records that satisfy the given predicate</dd> |
| <dt>See Also:</dt> |
| <dd> |
| <ul class="see-list"> |
| <li><a href="#filterNot(org.apache.kafka.streams.kstream.Predicate)"><code>filterNot(Predicate)</code></a></li> |
| </ul> |
| </dd> |
| </dl> |
| </section> |
| </li> |
| <li> |
| <section class="detail" id="filterNot(org.apache.kafka.streams.kstream.Predicate)"> |
| <h3>filterNot</h3> |
| <div class="member-signature"><span class="return-type"><a href="KStream.html" title="interface in org.apache.kafka.streams.kstream">KStream</a><<a href="KStream.html" title="type parameter in KStream">K</a>,<wbr><a href="KStream.html" title="type parameter in KStream">V</a>></span> <span class="element-name">filterNot</span><wbr><span class="parameters">(<a href="Predicate.html" title="interface in org.apache.kafka.streams.kstream">Predicate</a><? super <a href="KStream.html" title="type parameter in KStream">K</a>,<wbr>? super <a href="KStream.html" title="type parameter in KStream">V</a>> predicate)</span></div> |
| <div class="block">Create a new <code>KStream</code> that consists all records of this stream which do <em>not</em> satisfy the given |
| predicate. |
| All records that <em>do</em> satisfy the predicate are dropped. |
| This is a stateless record-by-record operation.</div> |
| <dl class="notes"> |
| <dt>Parameters:</dt> |
| <dd><code>predicate</code> - a filter <a href="Predicate.html" title="interface in org.apache.kafka.streams.kstream"><code>Predicate</code></a> that is applied to each record</dd> |
| <dt>Returns:</dt> |
| <dd>a <code>KStream</code> that contains only those records that do <em>not</em> satisfy the given predicate</dd> |
| <dt>See Also:</dt> |
| <dd> |
| <ul class="see-list"> |
| <li><a href="#filter(org.apache.kafka.streams.kstream.Predicate)"><code>filter(Predicate)</code></a></li> |
| </ul> |
| </dd> |
| </dl> |
| </section> |
| </li> |
| <li> |
| <section class="detail" id="filterNot(org.apache.kafka.streams.kstream.Predicate,org.apache.kafka.streams.kstream.Named)"> |
| <h3>filterNot</h3> |
| <div class="member-signature"><span class="return-type"><a href="KStream.html" title="interface in org.apache.kafka.streams.kstream">KStream</a><<a href="KStream.html" title="type parameter in KStream">K</a>,<wbr><a href="KStream.html" title="type parameter in KStream">V</a>></span> <span class="element-name">filterNot</span><wbr><span class="parameters">(<a href="Predicate.html" title="interface in org.apache.kafka.streams.kstream">Predicate</a><? super <a href="KStream.html" title="type parameter in KStream">K</a>,<wbr>? super <a href="KStream.html" title="type parameter in KStream">V</a>> predicate, |
| <a href="Named.html" title="class in org.apache.kafka.streams.kstream">Named</a> named)</span></div> |
| <div class="block">Create a new <code>KStream</code> that consists all records of this stream which do <em>not</em> satisfy the given |
| predicate. |
| All records that <em>do</em> satisfy the predicate are dropped. |
| This is a stateless record-by-record operation.</div> |
| <dl class="notes"> |
| <dt>Parameters:</dt> |
| <dd><code>predicate</code> - a filter <a href="Predicate.html" title="interface in org.apache.kafka.streams.kstream"><code>Predicate</code></a> that is applied to each record</dd> |
| <dd><code>named</code> - a <a href="Named.html" title="class in org.apache.kafka.streams.kstream"><code>Named</code></a> config used to name the processor in the topology</dd> |
| <dt>Returns:</dt> |
| <dd>a <code>KStream</code> that contains only those records that do <em>not</em> satisfy the given predicate</dd> |
| <dt>See Also:</dt> |
| <dd> |
| <ul class="see-list"> |
| <li><a href="#filter(org.apache.kafka.streams.kstream.Predicate)"><code>filter(Predicate)</code></a></li> |
| </ul> |
| </dd> |
| </dl> |
| </section> |
| </li> |
| <li> |
| <section class="detail" id="selectKey(org.apache.kafka.streams.kstream.KeyValueMapper)"> |
| <h3>selectKey</h3> |
| <div class="member-signature"><span class="type-parameters"><KR></span> <span class="return-type"><a href="KStream.html" title="interface in org.apache.kafka.streams.kstream">KStream</a><KR,<wbr><a href="KStream.html" title="type parameter in KStream">V</a>></span> <span class="element-name">selectKey</span><wbr><span class="parameters">(<a href="KeyValueMapper.html" title="interface in org.apache.kafka.streams.kstream">KeyValueMapper</a><? super <a href="KStream.html" title="type parameter in KStream">K</a>,<wbr>? super <a href="KStream.html" title="type parameter in KStream">V</a>,<wbr>? extends KR> mapper)</span></div> |
| <div class="block">Set a new key (with possibly new type) for each input record. |
| The provided <a href="KeyValueMapper.html" title="interface in org.apache.kafka.streams.kstream"><code>KeyValueMapper</code></a> is applied to each input record and computes a new key for it. |
| Thus, an input record <code><K,V></code> can be transformed into an output record <code><K':V></code>. |
| This is a stateless record-by-record operation. |
| <p> |
| For example, you can use this transformation to set a key for a key-less input record <code><null,V></code> by |
| extracting a key from the value within your <a href="KeyValueMapper.html" title="interface in org.apache.kafka.streams.kstream"><code>KeyValueMapper</code></a>. The example below computes the new key as the |
| length of the value string. |
| <pre><code> |
| KStream<Byte[], String> keyLessStream = builder.stream("key-less-topic"); |
| KStream<Integer, String> keyedStream = keyLessStream.selectKey(new KeyValueMapper<Byte[], String, Integer> { |
| Integer apply(Byte[] key, String value) { |
| return value.length(); |
| } |
| }); |
| </code></pre> |
| Setting a new key might result in an internal data redistribution if a key based operator (like an aggregation or |
| join) is applied to the result <code>KStream</code>.</div> |
| <dl class="notes"> |
| <dt>Type Parameters:</dt> |
| <dd><code>KR</code> - the new key type of the result stream</dd> |
| <dt>Parameters:</dt> |
| <dd><code>mapper</code> - a <a href="KeyValueMapper.html" title="interface in org.apache.kafka.streams.kstream"><code>KeyValueMapper</code></a> that computes a new key for each record</dd> |
| <dt>Returns:</dt> |
| <dd>a <code>KStream</code> that contains records with new key (possibly of different type) and unmodified value</dd> |
| <dt>See Also:</dt> |
| <dd> |
| <ul class="see-list-long"> |
| <li><a href="#map(org.apache.kafka.streams.kstream.KeyValueMapper)"><code>map(KeyValueMapper)</code></a></li> |
| <li><a href="#flatMap(org.apache.kafka.streams.kstream.KeyValueMapper)"><code>flatMap(KeyValueMapper)</code></a></li> |
| <li><a href="#mapValues(org.apache.kafka.streams.kstream.ValueMapper)"><code>mapValues(ValueMapper)</code></a></li> |
| <li><a href="#mapValues(org.apache.kafka.streams.kstream.ValueMapperWithKey)"><code>mapValues(ValueMapperWithKey)</code></a></li> |
| <li><a href="#flatMapValues(org.apache.kafka.streams.kstream.ValueMapper)"><code>flatMapValues(ValueMapper)</code></a></li> |
| <li><a href="#flatMapValues(org.apache.kafka.streams.kstream.ValueMapperWithKey)"><code>flatMapValues(ValueMapperWithKey)</code></a></li> |
| </ul> |
| </dd> |
| </dl> |
| </section> |
| </li> |
| <li> |
| <section class="detail" id="selectKey(org.apache.kafka.streams.kstream.KeyValueMapper,org.apache.kafka.streams.kstream.Named)"> |
| <h3>selectKey</h3> |
| <div class="member-signature"><span class="type-parameters"><KR></span> <span class="return-type"><a href="KStream.html" title="interface in org.apache.kafka.streams.kstream">KStream</a><KR,<wbr><a href="KStream.html" title="type parameter in KStream">V</a>></span> <span class="element-name">selectKey</span><wbr><span class="parameters">(<a href="KeyValueMapper.html" title="interface in org.apache.kafka.streams.kstream">KeyValueMapper</a><? super <a href="KStream.html" title="type parameter in KStream">K</a>,<wbr>? super <a href="KStream.html" title="type parameter in KStream">V</a>,<wbr>? extends KR> mapper, |
| <a href="Named.html" title="class in org.apache.kafka.streams.kstream">Named</a> named)</span></div> |
| <div class="block">Set a new key (with possibly new type) for each input record. |
| The provided <a href="KeyValueMapper.html" title="interface in org.apache.kafka.streams.kstream"><code>KeyValueMapper</code></a> is applied to each input record and computes a new key for it. |
| Thus, an input record <code><K,V></code> can be transformed into an output record <code><K':V></code>. |
| This is a stateless record-by-record operation. |
| <p> |
| For example, you can use this transformation to set a key for a key-less input record <code><null,V></code> by |
| extracting a key from the value within your <a href="KeyValueMapper.html" title="interface in org.apache.kafka.streams.kstream"><code>KeyValueMapper</code></a>. The example below computes the new key as the |
| length of the value string. |
| <pre><code> |
| KStream<Byte[], String> keyLessStream = builder.stream("key-less-topic"); |
| KStream<Integer, String> keyedStream = keyLessStream.selectKey(new KeyValueMapper<Byte[], String, Integer> { |
| Integer apply(Byte[] key, String value) { |
| return value.length(); |
| } |
| }); |
| </code></pre> |
| Setting a new key might result in an internal data redistribution if a key based operator (like an aggregation or |
| join) is applied to the result <code>KStream</code>.</div> |
| <dl class="notes"> |
| <dt>Type Parameters:</dt> |
| <dd><code>KR</code> - the new key type of the result stream</dd> |
| <dt>Parameters:</dt> |
| <dd><code>mapper</code> - a <a href="KeyValueMapper.html" title="interface in org.apache.kafka.streams.kstream"><code>KeyValueMapper</code></a> that computes a new key for each record</dd> |
| <dd><code>named</code> - a <a href="Named.html" title="class in org.apache.kafka.streams.kstream"><code>Named</code></a> config used to name the processor in the topology</dd> |
| <dt>Returns:</dt> |
| <dd>a <code>KStream</code> that contains records with new key (possibly of different type) and unmodified value</dd> |
| <dt>See Also:</dt> |
| <dd> |
| <ul class="see-list-long"> |
| <li><a href="#map(org.apache.kafka.streams.kstream.KeyValueMapper)"><code>map(KeyValueMapper)</code></a></li> |
| <li><a href="#flatMap(org.apache.kafka.streams.kstream.KeyValueMapper)"><code>flatMap(KeyValueMapper)</code></a></li> |
| <li><a href="#mapValues(org.apache.kafka.streams.kstream.ValueMapper)"><code>mapValues(ValueMapper)</code></a></li> |
| <li><a href="#mapValues(org.apache.kafka.streams.kstream.ValueMapperWithKey)"><code>mapValues(ValueMapperWithKey)</code></a></li> |
| <li><a href="#flatMapValues(org.apache.kafka.streams.kstream.ValueMapper)"><code>flatMapValues(ValueMapper)</code></a></li> |
| <li><a href="#flatMapValues(org.apache.kafka.streams.kstream.ValueMapperWithKey)"><code>flatMapValues(ValueMapperWithKey)</code></a></li> |
| </ul> |
| </dd> |
| </dl> |
| </section> |
| </li> |
| <li> |
| <section class="detail" id="map(org.apache.kafka.streams.kstream.KeyValueMapper)"> |
| <h3>map</h3> |
| <div class="member-signature"><span class="type-parameters"><KR,<wbr> |
| VR></span> <span class="return-type"><a href="KStream.html" title="interface in org.apache.kafka.streams.kstream">KStream</a><KR,<wbr>VR></span> <span class="element-name">map</span><wbr><span class="parameters">(<a href="KeyValueMapper.html" title="interface in org.apache.kafka.streams.kstream">KeyValueMapper</a><? super <a href="KStream.html" title="type parameter in KStream">K</a>,<wbr>? super <a href="KStream.html" title="type parameter in KStream">V</a>,<wbr>? extends <a href="../KeyValue.html" title="class in org.apache.kafka.streams">KeyValue</a><? extends KR,<wbr>? extends VR>> mapper)</span></div> |
| <div class="block">Transform each record of the input stream into a new record in the output stream (both key and value type can be |
| altered arbitrarily). |
| The provided <a href="KeyValueMapper.html" title="interface in org.apache.kafka.streams.kstream"><code>KeyValueMapper</code></a> is applied to each input record and computes a new output record. |
| Thus, an input record <code><K,V></code> can be transformed into an output record <code><K':V'></code>. |
| This is a stateless record-by-record operation (cf. <a href="#transform(org.apache.kafka.streams.kstream.TransformerSupplier,java.lang.String...)"><code>transform(TransformerSupplier, String...)</code></a> for |
| stateful record transformation). |
| <p> |
| The example below normalizes the String key to upper-case letters and counts the number of token of the value string. |
| <pre><code> |
| KStream<String, String> inputStream = builder.stream("topic"); |
| KStream<String, Integer> outputStream = inputStream.map(new KeyValueMapper<String, String, KeyValue<String, Integer>> { |
| KeyValue<String, Integer> apply(String key, String value) { |
| return new KeyValue<>(key.toUpperCase(), value.split(" ").length); |
| } |
| }); |
| </code></pre> |
| The provided <a href="KeyValueMapper.html" title="interface in org.apache.kafka.streams.kstream"><code>KeyValueMapper</code></a> must return a <a href="../KeyValue.html" title="class in org.apache.kafka.streams"><code>KeyValue</code></a> type and must not return <code>null</code>. |
| <p> |
| Mapping records might result in an internal data redistribution if a key based operator (like an aggregation or |
| join) is applied to the result <code>KStream</code>. (cf. <a href="#mapValues(org.apache.kafka.streams.kstream.ValueMapper)"><code>mapValues(ValueMapper)</code></a>)</div> |
| <dl class="notes"> |
| <dt>Type Parameters:</dt> |
| <dd><code>KR</code> - the key type of the result stream</dd> |
| <dd><code>VR</code> - the value type of the result stream</dd> |
| <dt>Parameters:</dt> |
| <dd><code>mapper</code> - a <a href="KeyValueMapper.html" title="interface in org.apache.kafka.streams.kstream"><code>KeyValueMapper</code></a> that computes a new output record</dd> |
| <dt>Returns:</dt> |
| <dd>a <code>KStream</code> that contains records with new key and value (possibly both of different type)</dd> |
| <dt>See Also:</dt> |
| <dd> |
| <ul class="see-list-long"> |
| <li><a href="#selectKey(org.apache.kafka.streams.kstream.KeyValueMapper)"><code>selectKey(KeyValueMapper)</code></a></li> |
| <li><a href="#flatMap(org.apache.kafka.streams.kstream.KeyValueMapper)"><code>flatMap(KeyValueMapper)</code></a></li> |
| <li><a href="#mapValues(org.apache.kafka.streams.kstream.ValueMapper)"><code>mapValues(ValueMapper)</code></a></li> |
| <li><a href="#mapValues(org.apache.kafka.streams.kstream.ValueMapperWithKey)"><code>mapValues(ValueMapperWithKey)</code></a></li> |
| <li><a href="#flatMapValues(org.apache.kafka.streams.kstream.ValueMapper)"><code>flatMapValues(ValueMapper)</code></a></li> |
| <li><a href="#flatMapValues(org.apache.kafka.streams.kstream.ValueMapperWithKey)"><code>flatMapValues(ValueMapperWithKey)</code></a></li> |
| <li><a href="#transform(org.apache.kafka.streams.kstream.TransformerSupplier,java.lang.String...)"><code>transform(TransformerSupplier, String...)</code></a></li> |
| <li><a href="#transformValues(org.apache.kafka.streams.kstream.ValueTransformerSupplier,java.lang.String...)"><code>transformValues(ValueTransformerSupplier, String...)</code></a></li> |
| <li><a href="#transformValues(org.apache.kafka.streams.kstream.ValueTransformerWithKeySupplier,java.lang.String...)"><code>transformValues(ValueTransformerWithKeySupplier, String...)</code></a></li> |
| </ul> |
| </dd> |
| </dl> |
| </section> |
| </li> |
| <li> |
| <section class="detail" id="map(org.apache.kafka.streams.kstream.KeyValueMapper,org.apache.kafka.streams.kstream.Named)"> |
| <h3>map</h3> |
| <div class="member-signature"><span class="type-parameters"><KR,<wbr> |
| VR></span> <span class="return-type"><a href="KStream.html" title="interface in org.apache.kafka.streams.kstream">KStream</a><KR,<wbr>VR></span> <span class="element-name">map</span><wbr><span class="parameters">(<a href="KeyValueMapper.html" title="interface in org.apache.kafka.streams.kstream">KeyValueMapper</a><? super <a href="KStream.html" title="type parameter in KStream">K</a>,<wbr>? super <a href="KStream.html" title="type parameter in KStream">V</a>,<wbr>? extends <a href="../KeyValue.html" title="class in org.apache.kafka.streams">KeyValue</a><? extends KR,<wbr>? extends VR>> mapper, |
| <a href="Named.html" title="class in org.apache.kafka.streams.kstream">Named</a> named)</span></div> |
| <div class="block">Transform each record of the input stream into a new record in the output stream (both key and value type can be |
| altered arbitrarily). |
| The provided <a href="KeyValueMapper.html" title="interface in org.apache.kafka.streams.kstream"><code>KeyValueMapper</code></a> is applied to each input record and computes a new output record. |
| Thus, an input record <code><K,V></code> can be transformed into an output record <code><K':V'></code>. |
| This is a stateless record-by-record operation (cf. <a href="#transform(org.apache.kafka.streams.kstream.TransformerSupplier,java.lang.String...)"><code>transform(TransformerSupplier, String...)</code></a> for |
| stateful record transformation). |
| <p> |
| The example below normalizes the String key to upper-case letters and counts the number of token of the value string. |
| <pre><code> |
| KStream<String, String> inputStream = builder.stream("topic"); |
| KStream<String, Integer> outputStream = inputStream.map(new KeyValueMapper<String, String, KeyValue<String, Integer>> { |
| KeyValue<String, Integer> apply(String key, String value) { |
| return new KeyValue<>(key.toUpperCase(), value.split(" ").length); |
| } |
| }); |
| </code></pre> |
| The provided <a href="KeyValueMapper.html" title="interface in org.apache.kafka.streams.kstream"><code>KeyValueMapper</code></a> must return a <a href="../KeyValue.html" title="class in org.apache.kafka.streams"><code>KeyValue</code></a> type and must not return <code>null</code>. |
| <p> |
| Mapping records might result in an internal data redistribution if a key based operator (like an aggregation or |
| join) is applied to the result <code>KStream</code>. (cf. <a href="#mapValues(org.apache.kafka.streams.kstream.ValueMapper)"><code>mapValues(ValueMapper)</code></a>)</div> |
| <dl class="notes"> |
| <dt>Type Parameters:</dt> |
| <dd><code>KR</code> - the key type of the result stream</dd> |
| <dd><code>VR</code> - the value type of the result stream</dd> |
| <dt>Parameters:</dt> |
| <dd><code>mapper</code> - a <a href="KeyValueMapper.html" title="interface in org.apache.kafka.streams.kstream"><code>KeyValueMapper</code></a> that computes a new output record</dd> |
| <dd><code>named</code> - a <a href="Named.html" title="class in org.apache.kafka.streams.kstream"><code>Named</code></a> config used to name the processor in the topology</dd> |
| <dt>Returns:</dt> |
| <dd>a <code>KStream</code> that contains records with new key and value (possibly both of different type)</dd> |
| <dt>See Also:</dt> |
| <dd> |
| <ul class="see-list-long"> |
| <li><a href="#selectKey(org.apache.kafka.streams.kstream.KeyValueMapper)"><code>selectKey(KeyValueMapper)</code></a></li> |
| <li><a href="#flatMap(org.apache.kafka.streams.kstream.KeyValueMapper)"><code>flatMap(KeyValueMapper)</code></a></li> |
| <li><a href="#mapValues(org.apache.kafka.streams.kstream.ValueMapper)"><code>mapValues(ValueMapper)</code></a></li> |
| <li><a href="#mapValues(org.apache.kafka.streams.kstream.ValueMapperWithKey)"><code>mapValues(ValueMapperWithKey)</code></a></li> |
| <li><a href="#flatMapValues(org.apache.kafka.streams.kstream.ValueMapper)"><code>flatMapValues(ValueMapper)</code></a></li> |
| <li><a href="#flatMapValues(org.apache.kafka.streams.kstream.ValueMapperWithKey)"><code>flatMapValues(ValueMapperWithKey)</code></a></li> |
| <li><a href="#transform(org.apache.kafka.streams.kstream.TransformerSupplier,java.lang.String...)"><code>transform(TransformerSupplier, String...)</code></a></li> |
| <li><a href="#transformValues(org.apache.kafka.streams.kstream.ValueTransformerSupplier,java.lang.String...)"><code>transformValues(ValueTransformerSupplier, String...)</code></a></li> |
| <li><a href="#transformValues(org.apache.kafka.streams.kstream.ValueTransformerWithKeySupplier,java.lang.String...)"><code>transformValues(ValueTransformerWithKeySupplier, String...)</code></a></li> |
| </ul> |
| </dd> |
| </dl> |
| </section> |
| </li> |
| <li> |
| <section class="detail" id="mapValues(org.apache.kafka.streams.kstream.ValueMapper)"> |
| <h3>mapValues</h3> |
| <div class="member-signature"><span class="type-parameters"><VR></span> <span class="return-type"><a href="KStream.html" title="interface in org.apache.kafka.streams.kstream">KStream</a><<a href="KStream.html" title="type parameter in KStream">K</a>,<wbr>VR></span> <span class="element-name">mapValues</span><wbr><span class="parameters">(<a href="ValueMapper.html" title="interface in org.apache.kafka.streams.kstream">ValueMapper</a><? super <a href="KStream.html" title="type parameter in KStream">V</a>,<wbr>? extends VR> mapper)</span></div> |
| <div class="block">Transform the value of each input record into a new value (with possible new type) of the output record. |
| The provided <a href="ValueMapper.html" title="interface in org.apache.kafka.streams.kstream"><code>ValueMapper</code></a> is applied to each input record value and computes a new value for it. |
| Thus, an input record <code><K,V></code> can be transformed into an output record <code><K:V'></code>. |
| This is a stateless record-by-record operation (cf. |
| <a href="#transformValues(org.apache.kafka.streams.kstream.ValueTransformerSupplier,java.lang.String...)"><code>transformValues(ValueTransformerSupplier, String...)</code></a> for stateful value transformation). |
| <p> |
| The example below counts the number of token of the value string. |
| <pre><code> |
| KStream<String, String> inputStream = builder.stream("topic"); |
| KStream<String, Integer> outputStream = inputStream.mapValues(new ValueMapper<String, Integer> { |
| Integer apply(String value) { |
| return value.split(" ").length; |
| } |
| }); |
| </code></pre> |
| Setting a new value preserves data co-location with respect to the key. |
| Thus, <em>no</em> internal data redistribution is required if a key based operator (like an aggregation or join) |
| is applied to the result <code>KStream</code>. (cf. <a href="#map(org.apache.kafka.streams.kstream.KeyValueMapper)"><code>map(KeyValueMapper)</code></a>)</div> |
| <dl class="notes"> |
| <dt>Type Parameters:</dt> |
| <dd><code>VR</code> - the value type of the result stream</dd> |
| <dt>Parameters:</dt> |
| <dd><code>mapper</code> - a <a href="ValueMapper.html" title="interface in org.apache.kafka.streams.kstream"><code>ValueMapper</code></a> that computes a new output value</dd> |
| <dt>Returns:</dt> |
| <dd>a <code>KStream</code> that contains records with unmodified key and new values (possibly of different type)</dd> |
| <dt>See Also:</dt> |
| <dd> |
| <ul class="see-list-long"> |
| <li><a href="#selectKey(org.apache.kafka.streams.kstream.KeyValueMapper)"><code>selectKey(KeyValueMapper)</code></a></li> |
| <li><a href="#map(org.apache.kafka.streams.kstream.KeyValueMapper)"><code>map(KeyValueMapper)</code></a></li> |
| <li><a href="#flatMap(org.apache.kafka.streams.kstream.KeyValueMapper)"><code>flatMap(KeyValueMapper)</code></a></li> |
| <li><a href="#flatMapValues(org.apache.kafka.streams.kstream.ValueMapper)"><code>flatMapValues(ValueMapper)</code></a></li> |
| <li><a href="#flatMapValues(org.apache.kafka.streams.kstream.ValueMapperWithKey)"><code>flatMapValues(ValueMapperWithKey)</code></a></li> |
| <li><a href="#transform(org.apache.kafka.streams.kstream.TransformerSupplier,java.lang.String...)"><code>transform(TransformerSupplier, String...)</code></a></li> |
| <li><a href="#transformValues(org.apache.kafka.streams.kstream.ValueTransformerSupplier,java.lang.String...)"><code>transformValues(ValueTransformerSupplier, String...)</code></a></li> |
| <li><a href="#transformValues(org.apache.kafka.streams.kstream.ValueTransformerWithKeySupplier,java.lang.String...)"><code>transformValues(ValueTransformerWithKeySupplier, String...)</code></a></li> |
| </ul> |
| </dd> |
| </dl> |
| </section> |
| </li> |
| <li> |
| <section class="detail" id="mapValues(org.apache.kafka.streams.kstream.ValueMapper,org.apache.kafka.streams.kstream.Named)"> |
| <h3>mapValues</h3> |
| <div class="member-signature"><span class="type-parameters"><VR></span> <span class="return-type"><a href="KStream.html" title="interface in org.apache.kafka.streams.kstream">KStream</a><<a href="KStream.html" title="type parameter in KStream">K</a>,<wbr>VR></span> <span class="element-name">mapValues</span><wbr><span class="parameters">(<a href="ValueMapper.html" title="interface in org.apache.kafka.streams.kstream">ValueMapper</a><? super <a href="KStream.html" title="type parameter in KStream">V</a>,<wbr>? extends VR> mapper, |
| <a href="Named.html" title="class in org.apache.kafka.streams.kstream">Named</a> named)</span></div> |
| <div class="block">Transform the value of each input record into a new value (with possible new type) of the output record. |
| The provided <a href="ValueMapper.html" title="interface in org.apache.kafka.streams.kstream"><code>ValueMapper</code></a> is applied to each input record value and computes a new value for it. |
| Thus, an input record <code><K,V></code> can be transformed into an output record <code><K:V'></code>. |
| This is a stateless record-by-record operation (cf. |
| <a href="#transformValues(org.apache.kafka.streams.kstream.ValueTransformerSupplier,java.lang.String...)"><code>transformValues(ValueTransformerSupplier, String...)</code></a> for stateful value transformation). |
| <p> |
| The example below counts the number of token of the value string. |
| <pre><code> |
| KStream<String, String> inputStream = builder.stream("topic"); |
| KStream<String, Integer> outputStream = inputStream.mapValues(new ValueMapper<String, Integer> { |
| Integer apply(String value) { |
| return value.split(" ").length; |
| } |
| }); |
| </code></pre> |
| Setting a new value preserves data co-location with respect to the key. |
| Thus, <em>no</em> internal data redistribution is required if a key based operator (like an aggregation or join) |
| is applied to the result <code>KStream</code>. (cf. <a href="#map(org.apache.kafka.streams.kstream.KeyValueMapper)"><code>map(KeyValueMapper)</code></a>)</div> |
| <dl class="notes"> |
| <dt>Type Parameters:</dt> |
| <dd><code>VR</code> - the value type of the result stream</dd> |
| <dt>Parameters:</dt> |
| <dd><code>mapper</code> - a <a href="ValueMapper.html" title="interface in org.apache.kafka.streams.kstream"><code>ValueMapper</code></a> that computes a new output value</dd> |
| <dd><code>named</code> - a <a href="Named.html" title="class in org.apache.kafka.streams.kstream"><code>Named</code></a> config used to name the processor in the topology</dd> |
| <dt>Returns:</dt> |
| <dd>a <code>KStream</code> that contains records with unmodified key and new values (possibly of different type)</dd> |
| <dt>See Also:</dt> |
| <dd> |
| <ul class="see-list-long"> |
| <li><a href="#selectKey(org.apache.kafka.streams.kstream.KeyValueMapper)"><code>selectKey(KeyValueMapper)</code></a></li> |
| <li><a href="#map(org.apache.kafka.streams.kstream.KeyValueMapper)"><code>map(KeyValueMapper)</code></a></li> |
| <li><a href="#flatMap(org.apache.kafka.streams.kstream.KeyValueMapper)"><code>flatMap(KeyValueMapper)</code></a></li> |
| <li><a href="#flatMapValues(org.apache.kafka.streams.kstream.ValueMapper)"><code>flatMapValues(ValueMapper)</code></a></li> |
| <li><a href="#flatMapValues(org.apache.kafka.streams.kstream.ValueMapperWithKey)"><code>flatMapValues(ValueMapperWithKey)</code></a></li> |
| <li><a href="#transform(org.apache.kafka.streams.kstream.TransformerSupplier,java.lang.String...)"><code>transform(TransformerSupplier, String...)</code></a></li> |
| <li><a href="#transformValues(org.apache.kafka.streams.kstream.ValueTransformerSupplier,java.lang.String...)"><code>transformValues(ValueTransformerSupplier, String...)</code></a></li> |
| <li><a href="#transformValues(org.apache.kafka.streams.kstream.ValueTransformerWithKeySupplier,java.lang.String...)"><code>transformValues(ValueTransformerWithKeySupplier, String...)</code></a></li> |
| </ul> |
| </dd> |
| </dl> |
| </section> |
| </li> |
| <li> |
| <section class="detail" id="mapValues(org.apache.kafka.streams.kstream.ValueMapperWithKey)"> |
| <h3>mapValues</h3> |
| <div class="member-signature"><span class="type-parameters"><VR></span> <span class="return-type"><a href="KStream.html" title="interface in org.apache.kafka.streams.kstream">KStream</a><<a href="KStream.html" title="type parameter in KStream">K</a>,<wbr>VR></span> <span class="element-name">mapValues</span><wbr><span class="parameters">(<a href="ValueMapperWithKey.html" title="interface in org.apache.kafka.streams.kstream">ValueMapperWithKey</a><? super <a href="KStream.html" title="type parameter in KStream">K</a>,<wbr>? super <a href="KStream.html" title="type parameter in KStream">V</a>,<wbr>? extends VR> mapper)</span></div> |
| <div class="block">Transform the value of each input record into a new value (with possible new type) of the output record. |
| The provided <a href="ValueMapperWithKey.html" title="interface in org.apache.kafka.streams.kstream"><code>ValueMapperWithKey</code></a> is applied to each input record value and computes a new value for it. |
| Thus, an input record <code><K,V></code> can be transformed into an output record <code><K:V'></code>. |
| This is a stateless record-by-record operation (cf. |
| <a href="#transformValues(org.apache.kafka.streams.kstream.ValueTransformerWithKeySupplier,java.lang.String...)"><code>transformValues(ValueTransformerWithKeySupplier, String...)</code></a> for stateful value transformation). |
| <p> |
| The example below counts the number of tokens of key and value strings. |
| <pre><code> |
| KStream<String, String> inputStream = builder.stream("topic"); |
| KStream<String, Integer> outputStream = inputStream.mapValues(new ValueMapperWithKey<String, String, Integer> { |
| Integer apply(String readOnlyKey, String value) { |
| return readOnlyKey.split(" ").length + value.split(" ").length; |
| } |
| }); |
| </code></pre> |
| Note that the key is read-only and should not be modified, as this can lead to corrupt partitioning. |
| So, setting a new value preserves data co-location with respect to the key. |
| Thus, <em>no</em> internal data redistribution is required if a key based operator (like an aggregation or join) |
| is applied to the result <code>KStream</code>. (cf. <a href="#map(org.apache.kafka.streams.kstream.KeyValueMapper)"><code>map(KeyValueMapper)</code></a>)</div> |
| <dl class="notes"> |
| <dt>Type Parameters:</dt> |
| <dd><code>VR</code> - the value type of the result stream</dd> |
| <dt>Parameters:</dt> |
| <dd><code>mapper</code> - a <a href="ValueMapperWithKey.html" title="interface in org.apache.kafka.streams.kstream"><code>ValueMapperWithKey</code></a> that computes a new output value</dd> |
| <dt>Returns:</dt> |
| <dd>a <code>KStream</code> that contains records with unmodified key and new values (possibly of different type)</dd> |
| <dt>See Also:</dt> |
| <dd> |
| <ul class="see-list-long"> |
| <li><a href="#selectKey(org.apache.kafka.streams.kstream.KeyValueMapper)"><code>selectKey(KeyValueMapper)</code></a></li> |
| <li><a href="#map(org.apache.kafka.streams.kstream.KeyValueMapper)"><code>map(KeyValueMapper)</code></a></li> |
| <li><a href="#flatMap(org.apache.kafka.streams.kstream.KeyValueMapper)"><code>flatMap(KeyValueMapper)</code></a></li> |
| <li><a href="#flatMapValues(org.apache.kafka.streams.kstream.ValueMapper)"><code>flatMapValues(ValueMapper)</code></a></li> |
| <li><a href="#flatMapValues(org.apache.kafka.streams.kstream.ValueMapperWithKey)"><code>flatMapValues(ValueMapperWithKey)</code></a></li> |
| <li><a href="#transform(org.apache.kafka.streams.kstream.TransformerSupplier,java.lang.String...)"><code>transform(TransformerSupplier, String...)</code></a></li> |
| <li><a href="#transformValues(org.apache.kafka.streams.kstream.ValueTransformerSupplier,java.lang.String...)"><code>transformValues(ValueTransformerSupplier, String...)</code></a></li> |
| <li><a href="#transformValues(org.apache.kafka.streams.kstream.ValueTransformerWithKeySupplier,java.lang.String...)"><code>transformValues(ValueTransformerWithKeySupplier, String...)</code></a></li> |
| </ul> |
| </dd> |
| </dl> |
| </section> |
| </li> |
| <li> |
| <section class="detail" id="mapValues(org.apache.kafka.streams.kstream.ValueMapperWithKey,org.apache.kafka.streams.kstream.Named)"> |
| <h3>mapValues</h3> |
| <div class="member-signature"><span class="type-parameters"><VR></span> <span class="return-type"><a href="KStream.html" title="interface in org.apache.kafka.streams.kstream">KStream</a><<a href="KStream.html" title="type parameter in KStream">K</a>,<wbr>VR></span> <span class="element-name">mapValues</span><wbr><span class="parameters">(<a href="ValueMapperWithKey.html" title="interface in org.apache.kafka.streams.kstream">ValueMapperWithKey</a><? super <a href="KStream.html" title="type parameter in KStream">K</a>,<wbr>? super <a href="KStream.html" title="type parameter in KStream">V</a>,<wbr>? extends VR> mapper, |
| <a href="Named.html" title="class in org.apache.kafka.streams.kstream">Named</a> named)</span></div> |
| <div class="block">Transform the value of each input record into a new value (with possible new type) of the output record. |
| The provided <a href="ValueMapperWithKey.html" title="interface in org.apache.kafka.streams.kstream"><code>ValueMapperWithKey</code></a> is applied to each input record value and computes a new value for it. |
| Thus, an input record <code><K,V></code> can be transformed into an output record <code><K:V'></code>. |
| This is a stateless record-by-record operation (cf. |
| <a href="#transformValues(org.apache.kafka.streams.kstream.ValueTransformerWithKeySupplier,java.lang.String...)"><code>transformValues(ValueTransformerWithKeySupplier, String...)</code></a> for stateful value transformation). |
| <p> |
| The example below counts the number of tokens of key and value strings. |
| <pre><code> |
| KStream<String, String> inputStream = builder.stream("topic"); |
| KStream<String, Integer> outputStream = inputStream.mapValues(new ValueMapperWithKey<String, String, Integer> { |
| Integer apply(String readOnlyKey, String value) { |
| return readOnlyKey.split(" ").length + value.split(" ").length; |
| } |
| }); |
| </code></pre> |
| Note that the key is read-only and should not be modified, as this can lead to corrupt partitioning. |
| So, setting a new value preserves data co-location with respect to the key. |
| Thus, <em>no</em> internal data redistribution is required if a key based operator (like an aggregation or join) |
| is applied to the result <code>KStream</code>. (cf. <a href="#map(org.apache.kafka.streams.kstream.KeyValueMapper)"><code>map(KeyValueMapper)</code></a>)</div> |
| <dl class="notes"> |
| <dt>Type Parameters:</dt> |
| <dd><code>VR</code> - the value type of the result stream</dd> |
| <dt>Parameters:</dt> |
| <dd><code>mapper</code> - a <a href="ValueMapperWithKey.html" title="interface in org.apache.kafka.streams.kstream"><code>ValueMapperWithKey</code></a> that computes a new output value</dd> |
| <dd><code>named</code> - a <a href="Named.html" title="class in org.apache.kafka.streams.kstream"><code>Named</code></a> config used to name the processor in the topology</dd> |
| <dt>Returns:</dt> |
| <dd>a <code>KStream</code> that contains records with unmodified key and new values (possibly of different type)</dd> |
| <dt>See Also:</dt> |
| <dd> |
| <ul class="see-list-long"> |
| <li><a href="#selectKey(org.apache.kafka.streams.kstream.KeyValueMapper)"><code>selectKey(KeyValueMapper)</code></a></li> |
| <li><a href="#map(org.apache.kafka.streams.kstream.KeyValueMapper)"><code>map(KeyValueMapper)</code></a></li> |
| <li><a href="#flatMap(org.apache.kafka.streams.kstream.KeyValueMapper)"><code>flatMap(KeyValueMapper)</code></a></li> |
| <li><a href="#flatMapValues(org.apache.kafka.streams.kstream.ValueMapper)"><code>flatMapValues(ValueMapper)</code></a></li> |
| <li><a href="#flatMapValues(org.apache.kafka.streams.kstream.ValueMapperWithKey)"><code>flatMapValues(ValueMapperWithKey)</code></a></li> |
| <li><a href="#transform(org.apache.kafka.streams.kstream.TransformerSupplier,java.lang.String...)"><code>transform(TransformerSupplier, String...)</code></a></li> |
| <li><a href="#transformValues(org.apache.kafka.streams.kstream.ValueTransformerSupplier,java.lang.String...)"><code>transformValues(ValueTransformerSupplier, String...)</code></a></li> |
| <li><a href="#transformValues(org.apache.kafka.streams.kstream.ValueTransformerWithKeySupplier,java.lang.String...)"><code>transformValues(ValueTransformerWithKeySupplier, String...)</code></a></li> |
| </ul> |
| </dd> |
| </dl> |
| </section> |
| </li> |
| <li> |
| <section class="detail" id="flatMap(org.apache.kafka.streams.kstream.KeyValueMapper)"> |
| <h3>flatMap</h3> |
| <div class="member-signature"><span class="type-parameters"><KR,<wbr> |
| VR></span> <span class="return-type"><a href="KStream.html" title="interface in org.apache.kafka.streams.kstream">KStream</a><KR,<wbr>VR></span> <span class="element-name">flatMap</span><wbr><span class="parameters">(<a href="KeyValueMapper.html" title="interface in org.apache.kafka.streams.kstream">KeyValueMapper</a><? super <a href="KStream.html" title="type parameter in KStream">K</a>,<wbr>? super <a href="KStream.html" title="type parameter in KStream">V</a>,<wbr>? extends <a href="https://docs.oracle.com/en/java/javase/17/docs/api/java.base/java/lang/Iterable.html" title="class or interface in java.lang" class="external-link">Iterable</a><? extends <a href="../KeyValue.html" title="class in org.apache.kafka.streams">KeyValue</a><? extends KR,<wbr>? extends VR>>> mapper)</span></div> |
| <div class="block">Transform each record of the input stream into zero or more records in the output stream (both key and value type |
| can be altered arbitrarily). |
| The provided <a href="KeyValueMapper.html" title="interface in org.apache.kafka.streams.kstream"><code>KeyValueMapper</code></a> is applied to each input record and computes zero or more output records. |
| Thus, an input record <code><K,V></code> can be transformed into output records <code><K':V'>, <K'':V''>, ...</code>. |
| This is a stateless record-by-record operation (cf. <a href="#transform(org.apache.kafka.streams.kstream.TransformerSupplier,java.lang.String...)"><code>transform(TransformerSupplier, String...)</code></a> for |
| stateful record transformation). |
| <p> |
| The example below splits input records <code><null:String></code> containing sentences as values into their words |
| and emit a record <code><word:1></code> for each word. |
| <pre><code> |
| KStream<byte[], String> inputStream = builder.stream("topic"); |
| KStream<String, Integer> outputStream = inputStream.flatMap( |
| new KeyValueMapper<byte[], String, Iterable<KeyValue<String, Integer>>> { |
| Iterable<KeyValue<String, Integer>> apply(byte[] key, String value) { |
| String[] tokens = value.split(" "); |
| List<KeyValue<String, Integer>> result = new ArrayList<>(tokens.length); |
| |
| for(String token : tokens) { |
| result.add(new KeyValue<>(token, 1)); |
| } |
| |
| return result; |
| } |
| }); |
| </code></pre> |
| The provided <a href="KeyValueMapper.html" title="interface in org.apache.kafka.streams.kstream"><code>KeyValueMapper</code></a> must return an <a href="https://docs.oracle.com/en/java/javase/17/docs/api/java.base/java/lang/Iterable.html" title="class or interface in java.lang" class="external-link"><code>Iterable</code></a> (e.g., any <a href="https://docs.oracle.com/en/java/javase/17/docs/api/java.base/java/util/Collection.html" title="class or interface in java.util" class="external-link"><code>Collection</code></a> type) |
| and the return value must not be <code>null</code>. |
| <p> |
| Flat-mapping records might result in an internal data redistribution if a key based operator (like an aggregation |
| or join) is applied to the result <code>KStream</code>. (cf. <a href="#flatMapValues(org.apache.kafka.streams.kstream.ValueMapper)"><code>flatMapValues(ValueMapper)</code></a>)</div> |
| <dl class="notes"> |
| <dt>Type Parameters:</dt> |
| <dd><code>KR</code> - the key type of the result stream</dd> |
| <dd><code>VR</code> - the value type of the result stream</dd> |
| <dt>Parameters:</dt> |
| <dd><code>mapper</code> - a <a href="KeyValueMapper.html" title="interface in org.apache.kafka.streams.kstream"><code>KeyValueMapper</code></a> that computes the new output records</dd> |
| <dt>Returns:</dt> |
| <dd>a <code>KStream</code> that contains more or less records with new key and value (possibly of different type)</dd> |
| <dt>See Also:</dt> |
| <dd> |
| <ul class="see-list-long"> |
| <li><a href="#selectKey(org.apache.kafka.streams.kstream.KeyValueMapper)"><code>selectKey(KeyValueMapper)</code></a></li> |
| <li><a href="#map(org.apache.kafka.streams.kstream.KeyValueMapper)"><code>map(KeyValueMapper)</code></a></li> |
| <li><a href="#mapValues(org.apache.kafka.streams.kstream.ValueMapper)"><code>mapValues(ValueMapper)</code></a></li> |
| <li><a href="#mapValues(org.apache.kafka.streams.kstream.ValueMapperWithKey)"><code>mapValues(ValueMapperWithKey)</code></a></li> |
| <li><a href="#flatMapValues(org.apache.kafka.streams.kstream.ValueMapper)"><code>flatMapValues(ValueMapper)</code></a></li> |
| <li><a href="#flatMapValues(org.apache.kafka.streams.kstream.ValueMapperWithKey)"><code>flatMapValues(ValueMapperWithKey)</code></a></li> |
| <li><a href="#transform(org.apache.kafka.streams.kstream.TransformerSupplier,java.lang.String...)"><code>transform(TransformerSupplier, String...)</code></a></li> |
| <li><a href="#flatTransform(org.apache.kafka.streams.kstream.TransformerSupplier,java.lang.String...)"><code>flatTransform(TransformerSupplier, String...)</code></a></li> |
| <li><a href="#transformValues(org.apache.kafka.streams.kstream.ValueTransformerSupplier,java.lang.String...)"><code>transformValues(ValueTransformerSupplier, String...)</code></a></li> |
| <li><a href="#transformValues(org.apache.kafka.streams.kstream.ValueTransformerWithKeySupplier,java.lang.String...)"><code>transformValues(ValueTransformerWithKeySupplier, String...)</code></a></li> |
| <li><a href="#flatTransformValues(org.apache.kafka.streams.kstream.ValueTransformerSupplier,java.lang.String...)"><code>flatTransformValues(ValueTransformerSupplier, String...)</code></a></li> |
| <li><a href="#flatTransformValues(org.apache.kafka.streams.kstream.ValueTransformerWithKeySupplier,java.lang.String...)"><code>flatTransformValues(ValueTransformerWithKeySupplier, String...)</code></a></li> |
| </ul> |
| </dd> |
| </dl> |
| </section> |
| </li> |
| <li> |
| <section class="detail" id="flatMap(org.apache.kafka.streams.kstream.KeyValueMapper,org.apache.kafka.streams.kstream.Named)"> |
| <h3>flatMap</h3> |
| <div class="member-signature"><span class="type-parameters"><KR,<wbr> |
| VR></span> <span class="return-type"><a href="KStream.html" title="interface in org.apache.kafka.streams.kstream">KStream</a><KR,<wbr>VR></span> <span class="element-name">flatMap</span><wbr><span class="parameters">(<a href="KeyValueMapper.html" title="interface in org.apache.kafka.streams.kstream">KeyValueMapper</a><? super <a href="KStream.html" title="type parameter in KStream">K</a>,<wbr>? super <a href="KStream.html" title="type parameter in KStream">V</a>,<wbr>? extends <a href="https://docs.oracle.com/en/java/javase/17/docs/api/java.base/java/lang/Iterable.html" title="class or interface in java.lang" class="external-link">Iterable</a><? extends <a href="../KeyValue.html" title="class in org.apache.kafka.streams">KeyValue</a><? extends KR,<wbr>? extends VR>>> mapper, |
| <a href="Named.html" title="class in org.apache.kafka.streams.kstream">Named</a> named)</span></div> |
| <div class="block">Transform each record of the input stream into zero or more records in the output stream (both key and value type |
| can be altered arbitrarily). |
| The provided <a href="KeyValueMapper.html" title="interface in org.apache.kafka.streams.kstream"><code>KeyValueMapper</code></a> is applied to each input record and computes zero or more output records. |
| Thus, an input record <code><K,V></code> can be transformed into output records <code><K':V'>, <K'':V''>, ...</code>. |
| This is a stateless record-by-record operation (cf. <a href="#transform(org.apache.kafka.streams.kstream.TransformerSupplier,java.lang.String...)"><code>transform(TransformerSupplier, String...)</code></a> for |
| stateful record transformation). |
| <p> |
| The example below splits input records <code><null:String></code> containing sentences as values into their words |
| and emit a record <code><word:1></code> for each word. |
| <pre><code> |
| KStream<byte[], String> inputStream = builder.stream("topic"); |
| KStream<String, Integer> outputStream = inputStream.flatMap( |
| new KeyValueMapper<byte[], String, Iterable<KeyValue<String, Integer>>> { |
| Iterable<KeyValue<String, Integer>> apply(byte[] key, String value) { |
| String[] tokens = value.split(" "); |
| List<KeyValue<String, Integer>> result = new ArrayList<>(tokens.length); |
| |
| for(String token : tokens) { |
| result.add(new KeyValue<>(token, 1)); |
| } |
| |
| return result; |
| } |
| }); |
| </code></pre> |
| The provided <a href="KeyValueMapper.html" title="interface in org.apache.kafka.streams.kstream"><code>KeyValueMapper</code></a> must return an <a href="https://docs.oracle.com/en/java/javase/17/docs/api/java.base/java/lang/Iterable.html" title="class or interface in java.lang" class="external-link"><code>Iterable</code></a> (e.g., any <a href="https://docs.oracle.com/en/java/javase/17/docs/api/java.base/java/util/Collection.html" title="class or interface in java.util" class="external-link"><code>Collection</code></a> type) |
| and the return value must not be <code>null</code>. |
| <p> |
| Flat-mapping records might result in an internal data redistribution if a key based operator (like an aggregation |
| or join) is applied to the result <code>KStream</code>. (cf. <a href="#flatMapValues(org.apache.kafka.streams.kstream.ValueMapper)"><code>flatMapValues(ValueMapper)</code></a>)</div> |
| <dl class="notes"> |
| <dt>Type Parameters:</dt> |
| <dd><code>KR</code> - the key type of the result stream</dd> |
| <dd><code>VR</code> - the value type of the result stream</dd> |
| <dt>Parameters:</dt> |
| <dd><code>mapper</code> - a <a href="KeyValueMapper.html" title="interface in org.apache.kafka.streams.kstream"><code>KeyValueMapper</code></a> that computes the new output records</dd> |
| <dd><code>named</code> - a <a href="Named.html" title="class in org.apache.kafka.streams.kstream"><code>Named</code></a> config used to name the processor in the topology</dd> |
| <dt>Returns:</dt> |
| <dd>a <code>KStream</code> that contains more or less records with new key and value (possibly of different type)</dd> |
| <dt>See Also:</dt> |
| <dd> |
| <ul class="see-list-long"> |
| <li><a href="#selectKey(org.apache.kafka.streams.kstream.KeyValueMapper)"><code>selectKey(KeyValueMapper)</code></a></li> |
| <li><a href="#map(org.apache.kafka.streams.kstream.KeyValueMapper)"><code>map(KeyValueMapper)</code></a></li> |
| <li><a href="#mapValues(org.apache.kafka.streams.kstream.ValueMapper)"><code>mapValues(ValueMapper)</code></a></li> |
| <li><a href="#mapValues(org.apache.kafka.streams.kstream.ValueMapperWithKey)"><code>mapValues(ValueMapperWithKey)</code></a></li> |
| <li><a href="#flatMapValues(org.apache.kafka.streams.kstream.ValueMapper)"><code>flatMapValues(ValueMapper)</code></a></li> |
| <li><a href="#flatMapValues(org.apache.kafka.streams.kstream.ValueMapperWithKey)"><code>flatMapValues(ValueMapperWithKey)</code></a></li> |
| <li><a href="#transform(org.apache.kafka.streams.kstream.TransformerSupplier,java.lang.String...)"><code>transform(TransformerSupplier, String...)</code></a></li> |
| <li><a href="#flatTransform(org.apache.kafka.streams.kstream.TransformerSupplier,java.lang.String...)"><code>flatTransform(TransformerSupplier, String...)</code></a></li> |
| <li><a href="#transformValues(org.apache.kafka.streams.kstream.ValueTransformerSupplier,java.lang.String...)"><code>transformValues(ValueTransformerSupplier, String...)</code></a></li> |
| <li><a href="#transformValues(org.apache.kafka.streams.kstream.ValueTransformerWithKeySupplier,java.lang.String...)"><code>transformValues(ValueTransformerWithKeySupplier, String...)</code></a></li> |
| <li><a href="#flatTransformValues(org.apache.kafka.streams.kstream.ValueTransformerSupplier,java.lang.String...)"><code>flatTransformValues(ValueTransformerSupplier, String...)</code></a></li> |
| <li><a href="#flatTransformValues(org.apache.kafka.streams.kstream.ValueTransformerWithKeySupplier,java.lang.String...)"><code>flatTransformValues(ValueTransformerWithKeySupplier, String...)</code></a></li> |
| </ul> |
| </dd> |
| </dl> |
| </section> |
| </li> |
| <li> |
| <section class="detail" id="flatMapValues(org.apache.kafka.streams.kstream.ValueMapper)"> |
| <h3>flatMapValues</h3> |
| <div class="member-signature"><span class="type-parameters"><VR></span> <span class="return-type"><a href="KStream.html" title="interface in org.apache.kafka.streams.kstream">KStream</a><<a href="KStream.html" title="type parameter in KStream">K</a>,<wbr>VR></span> <span class="element-name">flatMapValues</span><wbr><span class="parameters">(<a href="ValueMapper.html" title="interface in org.apache.kafka.streams.kstream">ValueMapper</a><? super <a href="KStream.html" title="type parameter in KStream">V</a>,<wbr>? extends <a href="https://docs.oracle.com/en/java/javase/17/docs/api/java.base/java/lang/Iterable.html" title="class or interface in java.lang" class="external-link">Iterable</a><? extends VR>> mapper)</span></div> |
| <div class="block">Create a new <code>KStream</code> by transforming the value of each record in this stream into zero or more values |
| with the same key in the new stream. |
| Transform the value of each input record into zero or more records with the same (unmodified) key in the output |
| stream (value type can be altered arbitrarily). |
| The provided <a href="ValueMapper.html" title="interface in org.apache.kafka.streams.kstream"><code>ValueMapper</code></a> is applied to each input record and computes zero or more output values. |
| Thus, an input record <code><K,V></code> can be transformed into output records <code><K:V'>, <K:V''>, ...</code>. |
| This is a stateless record-by-record operation (cf. <a href="#transformValues(org.apache.kafka.streams.kstream.ValueTransformerSupplier,java.lang.String...)"><code>transformValues(ValueTransformerSupplier, String...)</code></a> |
| for stateful value transformation). |
| <p> |
| The example below splits input records <code><null:String></code> containing sentences as values into their words. |
| <pre><code> |
| KStream<byte[], String> inputStream = builder.stream("topic"); |
| KStream<byte[], String> outputStream = inputStream.flatMapValues(new ValueMapper<String, Iterable<String>> { |
| Iterable<String> apply(String value) { |
| return Arrays.asList(value.split(" ")); |
| } |
| }); |
| </code></pre> |
| The provided <a href="ValueMapper.html" title="interface in org.apache.kafka.streams.kstream"><code>ValueMapper</code></a> must return an <a href="https://docs.oracle.com/en/java/javase/17/docs/api/java.base/java/lang/Iterable.html" title="class or interface in java.lang" class="external-link"><code>Iterable</code></a> (e.g., any <a href="https://docs.oracle.com/en/java/javase/17/docs/api/java.base/java/util/Collection.html" title="class or interface in java.util" class="external-link"><code>Collection</code></a> type) |
| and the return value must not be <code>null</code>. |
| <p> |
| Splitting a record into multiple records with the same key preserves data co-location with respect to the key. |
| Thus, <em>no</em> internal data redistribution is required if a key based operator (like an aggregation or join) |
| is applied to the result <code>KStream</code>. (cf. <a href="#flatMap(org.apache.kafka.streams.kstream.KeyValueMapper)"><code>flatMap(KeyValueMapper)</code></a>)</div> |
| <dl class="notes"> |
| <dt>Type Parameters:</dt> |
| <dd><code>VR</code> - the value type of the result stream</dd> |
| <dt>Parameters:</dt> |
| <dd><code>mapper</code> - a <a href="ValueMapper.html" title="interface in org.apache.kafka.streams.kstream"><code>ValueMapper</code></a> the computes the new output values</dd> |
| <dt>Returns:</dt> |
| <dd>a <code>KStream</code> that contains more or less records with unmodified keys and new values of different type</dd> |
| <dt>See Also:</dt> |
| <dd> |
| <ul class="see-list-long"> |
| <li><a href="#selectKey(org.apache.kafka.streams.kstream.KeyValueMapper)"><code>selectKey(KeyValueMapper)</code></a></li> |
| <li><a href="#map(org.apache.kafka.streams.kstream.KeyValueMapper)"><code>map(KeyValueMapper)</code></a></li> |
| <li><a href="#flatMap(org.apache.kafka.streams.kstream.KeyValueMapper)"><code>flatMap(KeyValueMapper)</code></a></li> |
| <li><a href="#mapValues(org.apache.kafka.streams.kstream.ValueMapper)"><code>mapValues(ValueMapper)</code></a></li> |
| <li><a href="#mapValues(org.apache.kafka.streams.kstream.ValueMapperWithKey)"><code>mapValues(ValueMapperWithKey)</code></a></li> |
| <li><a href="#transform(org.apache.kafka.streams.kstream.TransformerSupplier,java.lang.String...)"><code>transform(TransformerSupplier, String...)</code></a></li> |
| <li><a href="#flatTransform(org.apache.kafka.streams.kstream.TransformerSupplier,java.lang.String...)"><code>flatTransform(TransformerSupplier, String...)</code></a></li> |
| <li><a href="#transformValues(org.apache.kafka.streams.kstream.ValueTransformerSupplier,java.lang.String...)"><code>transformValues(ValueTransformerSupplier, String...)</code></a></li> |
| <li><a href="#transformValues(org.apache.kafka.streams.kstream.ValueTransformerWithKeySupplier,java.lang.String...)"><code>transformValues(ValueTransformerWithKeySupplier, String...)</code></a></li> |
| <li><a href="#flatTransformValues(org.apache.kafka.streams.kstream.ValueTransformerSupplier,java.lang.String...)"><code>flatTransformValues(ValueTransformerSupplier, String...)</code></a></li> |
| <li><a href="#flatTransformValues(org.apache.kafka.streams.kstream.ValueTransformerWithKeySupplier,java.lang.String...)"><code>flatTransformValues(ValueTransformerWithKeySupplier, String...)</code></a></li> |
| </ul> |
| </dd> |
| </dl> |
| </section> |
| </li> |
| <li> |
| <section class="detail" id="flatMapValues(org.apache.kafka.streams.kstream.ValueMapper,org.apache.kafka.streams.kstream.Named)"> |
| <h3>flatMapValues</h3> |
| <div class="member-signature"><span class="type-parameters"><VR></span> <span class="return-type"><a href="KStream.html" title="interface in org.apache.kafka.streams.kstream">KStream</a><<a href="KStream.html" title="type parameter in KStream">K</a>,<wbr>VR></span> <span class="element-name">flatMapValues</span><wbr><span class="parameters">(<a href="ValueMapper.html" title="interface in org.apache.kafka.streams.kstream">ValueMapper</a><? super <a href="KStream.html" title="type parameter in KStream">V</a>,<wbr>? extends <a href="https://docs.oracle.com/en/java/javase/17/docs/api/java.base/java/lang/Iterable.html" title="class or interface in java.lang" class="external-link">Iterable</a><? extends VR>> mapper, |
| <a href="Named.html" title="class in org.apache.kafka.streams.kstream">Named</a> named)</span></div> |
| <div class="block">Create a new <code>KStream</code> by transforming the value of each record in this stream into zero or more values |
| with the same key in the new stream. |
| Transform the value of each input record into zero or more records with the same (unmodified) key in the output |
| stream (value type can be altered arbitrarily). |
| The provided <a href="ValueMapper.html" title="interface in org.apache.kafka.streams.kstream"><code>ValueMapper</code></a> is applied to each input record and computes zero or more output values. |
| Thus, an input record <code><K,V></code> can be transformed into output records <code><K:V'>, <K:V''>, ...</code>. |
| This is a stateless record-by-record operation (cf. <a href="#transformValues(org.apache.kafka.streams.kstream.ValueTransformerSupplier,java.lang.String...)"><code>transformValues(ValueTransformerSupplier, String...)</code></a> |
| for stateful value transformation). |
| <p> |
| The example below splits input records <code><null:String></code> containing sentences as values into their words. |
| <pre><code> |
| KStream<byte[], String> inputStream = builder.stream("topic"); |
| KStream<byte[], String> outputStream = inputStream.flatMapValues(new ValueMapper<String, Iterable<String>> { |
| Iterable<String> apply(String value) { |
| return Arrays.asList(value.split(" ")); |
| } |
| }); |
| </code></pre> |
| The provided <a href="ValueMapper.html" title="interface in org.apache.kafka.streams.kstream"><code>ValueMapper</code></a> must return an <a href="https://docs.oracle.com/en/java/javase/17/docs/api/java.base/java/lang/Iterable.html" title="class or interface in java.lang" class="external-link"><code>Iterable</code></a> (e.g., any <a href="https://docs.oracle.com/en/java/javase/17/docs/api/java.base/java/util/Collection.html" title="class or interface in java.util" class="external-link"><code>Collection</code></a> type) |
| and the return value must not be <code>null</code>. |
| <p> |
| Splitting a record into multiple records with the same key preserves data co-location with respect to the key. |
| Thus, <em>no</em> internal data redistribution is required if a key based operator (like an aggregation or join) |
| is applied to the result <code>KStream</code>. (cf. <a href="#flatMap(org.apache.kafka.streams.kstream.KeyValueMapper)"><code>flatMap(KeyValueMapper)</code></a>)</div> |
| <dl class="notes"> |
| <dt>Type Parameters:</dt> |
| <dd><code>VR</code> - the value type of the result stream</dd> |
| <dt>Parameters:</dt> |
| <dd><code>mapper</code> - a <a href="ValueMapper.html" title="interface in org.apache.kafka.streams.kstream"><code>ValueMapper</code></a> the computes the new output values</dd> |
| <dd><code>named</code> - a <a href="Named.html" title="class in org.apache.kafka.streams.kstream"><code>Named</code></a> config used to name the processor in the topology</dd> |
| <dt>Returns:</dt> |
| <dd>a <code>KStream</code> that contains more or less records with unmodified keys and new values of different type</dd> |
| <dt>See Also:</dt> |
| <dd> |
| <ul class="see-list-long"> |
| <li><a href="#selectKey(org.apache.kafka.streams.kstream.KeyValueMapper)"><code>selectKey(KeyValueMapper)</code></a></li> |
| <li><a href="#map(org.apache.kafka.streams.kstream.KeyValueMapper)"><code>map(KeyValueMapper)</code></a></li> |
| <li><a href="#flatMap(org.apache.kafka.streams.kstream.KeyValueMapper)"><code>flatMap(KeyValueMapper)</code></a></li> |
| <li><a href="#mapValues(org.apache.kafka.streams.kstream.ValueMapper)"><code>mapValues(ValueMapper)</code></a></li> |
| <li><a href="#mapValues(org.apache.kafka.streams.kstream.ValueMapperWithKey)"><code>mapValues(ValueMapperWithKey)</code></a></li> |
| <li><a href="#transform(org.apache.kafka.streams.kstream.TransformerSupplier,java.lang.String...)"><code>transform(TransformerSupplier, String...)</code></a></li> |
| <li><a href="#flatTransform(org.apache.kafka.streams.kstream.TransformerSupplier,java.lang.String...)"><code>flatTransform(TransformerSupplier, String...)</code></a></li> |
| <li><a href="#transformValues(org.apache.kafka.streams.kstream.ValueTransformerSupplier,java.lang.String...)"><code>transformValues(ValueTransformerSupplier, String...)</code></a></li> |
| <li><a href="#transformValues(org.apache.kafka.streams.kstream.ValueTransformerWithKeySupplier,java.lang.String...)"><code>transformValues(ValueTransformerWithKeySupplier, String...)</code></a></li> |
| <li><a href="#flatTransformValues(org.apache.kafka.streams.kstream.ValueTransformerSupplier,java.lang.String...)"><code>flatTransformValues(ValueTransformerSupplier, String...)</code></a></li> |
| <li><a href="#flatTransformValues(org.apache.kafka.streams.kstream.ValueTransformerWithKeySupplier,java.lang.String...)"><code>flatTransformValues(ValueTransformerWithKeySupplier, String...)</code></a></li> |
| </ul> |
| </dd> |
| </dl> |
| </section> |
| </li> |
| <li> |
| <section class="detail" id="flatMapValues(org.apache.kafka.streams.kstream.ValueMapperWithKey)"> |
| <h3>flatMapValues</h3> |
| <div class="member-signature"><span class="type-parameters"><VR></span> <span class="return-type"><a href="KStream.html" title="interface in org.apache.kafka.streams.kstream">KStream</a><<a href="KStream.html" title="type parameter in KStream">K</a>,<wbr>VR></span> <span class="element-name">flatMapValues</span><wbr><span class="parameters">(<a href="ValueMapperWithKey.html" title="interface in org.apache.kafka.streams.kstream">ValueMapperWithKey</a><? super <a href="KStream.html" title="type parameter in KStream">K</a>,<wbr>? super <a href="KStream.html" title="type parameter in KStream">V</a>,<wbr>? extends <a href="https://docs.oracle.com/en/java/javase/17/docs/api/java.base/java/lang/Iterable.html" title="class or interface in java.lang" class="external-link">Iterable</a><? extends VR>> mapper)</span></div> |
| <div class="block">Create a new <code>KStream</code> by transforming the value of each record in this stream into zero or more values |
| with the same key in the new stream. |
| Transform the value of each input record into zero or more records with the same (unmodified) key in the output |
| stream (value type can be altered arbitrarily). |
| The provided <a href="ValueMapperWithKey.html" title="interface in org.apache.kafka.streams.kstream"><code>ValueMapperWithKey</code></a> is applied to each input record and computes zero or more output values. |
| Thus, an input record <code><K,V></code> can be transformed into output records <code><K:V'>, <K:V''>, ...</code>. |
| This is a stateless record-by-record operation (cf. <a href="#transformValues(org.apache.kafka.streams.kstream.ValueTransformerWithKeySupplier,java.lang.String...)"><code>transformValues(ValueTransformerWithKeySupplier, String...)</code></a> |
| for stateful value transformation). |
| <p> |
| The example below splits input records <code><Integer:String></code>, with key=1, containing sentences as values |
| into their words. |
| <pre><code> |
| KStream<Integer, String> inputStream = builder.stream("topic"); |
| KStream<Integer, String> outputStream = inputStream.flatMapValues(new ValueMapper<Integer, String, Iterable<String>> { |
| Iterable<Integer, String> apply(Integer readOnlyKey, String value) { |
| if(readOnlyKey == 1) { |
| return Arrays.asList(value.split(" ")); |
| } else { |
| return Arrays.asList(value); |
| } |
| } |
| }); |
| </code></pre> |
| The provided <a href="ValueMapperWithKey.html" title="interface in org.apache.kafka.streams.kstream"><code>ValueMapperWithKey</code></a> must return an <a href="https://docs.oracle.com/en/java/javase/17/docs/api/java.base/java/lang/Iterable.html" title="class or interface in java.lang" class="external-link"><code>Iterable</code></a> (e.g., any <a href="https://docs.oracle.com/en/java/javase/17/docs/api/java.base/java/util/Collection.html" title="class or interface in java.util" class="external-link"><code>Collection</code></a> type) |
| and the return value must not be <code>null</code>. |
| <p> |
| Note that the key is read-only and should not be modified, as this can lead to corrupt partitioning. |
| So, splitting a record into multiple records with the same key preserves data co-location with respect to the key. |
| Thus, <em>no</em> internal data redistribution is required if a key based operator (like an aggregation or join) |
| is applied to the result <code>KStream</code>. (cf. <a href="#flatMap(org.apache.kafka.streams.kstream.KeyValueMapper)"><code>flatMap(KeyValueMapper)</code></a>)</div> |
| <dl class="notes"> |
| <dt>Type Parameters:</dt> |
| <dd><code>VR</code> - the value type of the result stream</dd> |
| <dt>Parameters:</dt> |
| <dd><code>mapper</code> - a <a href="ValueMapperWithKey.html" title="interface in org.apache.kafka.streams.kstream"><code>ValueMapperWithKey</code></a> the computes the new output values</dd> |
| <dt>Returns:</dt> |
| <dd>a <code>KStream</code> that contains more or less records with unmodified keys and new values of different type</dd> |
| <dt>See Also:</dt> |
| <dd> |
| <ul class="see-list-long"> |
| <li><a href="#selectKey(org.apache.kafka.streams.kstream.KeyValueMapper)"><code>selectKey(KeyValueMapper)</code></a></li> |
| <li><a href="#map(org.apache.kafka.streams.kstream.KeyValueMapper)"><code>map(KeyValueMapper)</code></a></li> |
| <li><a href="#flatMap(org.apache.kafka.streams.kstream.KeyValueMapper)"><code>flatMap(KeyValueMapper)</code></a></li> |
| <li><a href="#mapValues(org.apache.kafka.streams.kstream.ValueMapper)"><code>mapValues(ValueMapper)</code></a></li> |
| <li><a href="#mapValues(org.apache.kafka.streams.kstream.ValueMapperWithKey)"><code>mapValues(ValueMapperWithKey)</code></a></li> |
| <li><a href="#transform(org.apache.kafka.streams.kstream.TransformerSupplier,java.lang.String...)"><code>transform(TransformerSupplier, String...)</code></a></li> |
| <li><a href="#flatTransform(org.apache.kafka.streams.kstream.TransformerSupplier,java.lang.String...)"><code>flatTransform(TransformerSupplier, String...)</code></a></li> |
| <li><a href="#transformValues(org.apache.kafka.streams.kstream.ValueTransformerSupplier,java.lang.String...)"><code>transformValues(ValueTransformerSupplier, String...)</code></a></li> |
| <li><a href="#transformValues(org.apache.kafka.streams.kstream.ValueTransformerWithKeySupplier,java.lang.String...)"><code>transformValues(ValueTransformerWithKeySupplier, String...)</code></a></li> |
| <li><a href="#flatTransformValues(org.apache.kafka.streams.kstream.ValueTransformerSupplier,java.lang.String...)"><code>flatTransformValues(ValueTransformerSupplier, String...)</code></a></li> |
| <li><a href="#flatTransformValues(org.apache.kafka.streams.kstream.ValueTransformerWithKeySupplier,java.lang.String...)"><code>flatTransformValues(ValueTransformerWithKeySupplier, String...)</code></a></li> |
| </ul> |
| </dd> |
| </dl> |
| </section> |
| </li> |
| <li> |
| <section class="detail" id="flatMapValues(org.apache.kafka.streams.kstream.ValueMapperWithKey,org.apache.kafka.streams.kstream.Named)"> |
| <h3>flatMapValues</h3> |
| <div class="member-signature"><span class="type-parameters"><VR></span> <span class="return-type"><a href="KStream.html" title="interface in org.apache.kafka.streams.kstream">KStream</a><<a href="KStream.html" title="type parameter in KStream">K</a>,<wbr>VR></span> <span class="element-name">flatMapValues</span><wbr><span class="parameters">(<a href="ValueMapperWithKey.html" title="interface in org.apache.kafka.streams.kstream">ValueMapperWithKey</a><? super <a href="KStream.html" title="type parameter in KStream">K</a>,<wbr>? super <a href="KStream.html" title="type parameter in KStream">V</a>,<wbr>? extends <a href="https://docs.oracle.com/en/java/javase/17/docs/api/java.base/java/lang/Iterable.html" title="class or interface in java.lang" class="external-link">Iterable</a><? extends VR>> mapper, |
| <a href="Named.html" title="class in org.apache.kafka.streams.kstream">Named</a> named)</span></div> |
| <div class="block">Create a new <code>KStream</code> by transforming the value of each record in this stream into zero or more values |
| with the same key in the new stream. |
| Transform the value of each input record into zero or more records with the same (unmodified) key in the output |
| stream (value type can be altered arbitrarily). |
| The provided <a href="ValueMapperWithKey.html" title="interface in org.apache.kafka.streams.kstream"><code>ValueMapperWithKey</code></a> is applied to each input record and computes zero or more output values. |
| Thus, an input record <code><K,V></code> can be transformed into output records <code><K:V'>, <K:V''>, ...</code>. |
| This is a stateless record-by-record operation (cf. <a href="#transformValues(org.apache.kafka.streams.kstream.ValueTransformerWithKeySupplier,java.lang.String...)"><code>transformValues(ValueTransformerWithKeySupplier, String...)</code></a> |
| for stateful value transformation). |
| <p> |
| The example below splits input records <code><Integer:String></code>, with key=1, containing sentences as values |
| into their words. |
| <pre><code> |
| KStream<Integer, String> inputStream = builder.stream("topic"); |
| KStream<Integer, String> outputStream = inputStream.flatMapValues(new ValueMapper<Integer, String, Iterable<String>> { |
| Iterable<Integer, String> apply(Integer readOnlyKey, String value) { |
| if(readOnlyKey == 1) { |
| return Arrays.asList(value.split(" ")); |
| } else { |
| return Arrays.asList(value); |
| } |
| } |
| }); |
| </code></pre> |
| The provided <a href="ValueMapperWithKey.html" title="interface in org.apache.kafka.streams.kstream"><code>ValueMapperWithKey</code></a> must return an <a href="https://docs.oracle.com/en/java/javase/17/docs/api/java.base/java/lang/Iterable.html" title="class or interface in java.lang" class="external-link"><code>Iterable</code></a> (e.g., any <a href="https://docs.oracle.com/en/java/javase/17/docs/api/java.base/java/util/Collection.html" title="class or interface in java.util" class="external-link"><code>Collection</code></a> type) |
| and the return value must not be <code>null</code>. |
| <p> |
| Note that the key is read-only and should not be modified, as this can lead to corrupt partitioning. |
| So, splitting a record into multiple records with the same key preserves data co-location with respect to the key. |
| Thus, <em>no</em> internal data redistribution is required if a key based operator (like an aggregation or join) |
| is applied to the result <code>KStream</code>. (cf. <a href="#flatMap(org.apache.kafka.streams.kstream.KeyValueMapper)"><code>flatMap(KeyValueMapper)</code></a>)</div> |
| <dl class="notes"> |
| <dt>Type Parameters:</dt> |
| <dd><code>VR</code> - the value type of the result stream</dd> |
| <dt>Parameters:</dt> |
| <dd><code>mapper</code> - a <a href="ValueMapperWithKey.html" title="interface in org.apache.kafka.streams.kstream"><code>ValueMapperWithKey</code></a> the computes the new output values</dd> |
| <dd><code>named</code> - a <a href="Named.html" title="class in org.apache.kafka.streams.kstream"><code>Named</code></a> config used to name the processor in the topology</dd> |
| <dt>Returns:</dt> |
| <dd>a <code>KStream</code> that contains more or less records with unmodified keys and new values of different type</dd> |
| <dt>See Also:</dt> |
| <dd> |
| <ul class="see-list-long"> |
| <li><a href="#selectKey(org.apache.kafka.streams.kstream.KeyValueMapper)"><code>selectKey(KeyValueMapper)</code></a></li> |
| <li><a href="#map(org.apache.kafka.streams.kstream.KeyValueMapper)"><code>map(KeyValueMapper)</code></a></li> |
| <li><a href="#flatMap(org.apache.kafka.streams.kstream.KeyValueMapper)"><code>flatMap(KeyValueMapper)</code></a></li> |
| <li><a href="#mapValues(org.apache.kafka.streams.kstream.ValueMapper)"><code>mapValues(ValueMapper)</code></a></li> |
| <li><a href="#mapValues(org.apache.kafka.streams.kstream.ValueMapperWithKey)"><code>mapValues(ValueMapperWithKey)</code></a></li> |
| <li><a href="#transform(org.apache.kafka.streams.kstream.TransformerSupplier,java.lang.String...)"><code>transform(TransformerSupplier, String...)</code></a></li> |
| <li><a href="#flatTransform(org.apache.kafka.streams.kstream.TransformerSupplier,java.lang.String...)"><code>flatTransform(TransformerSupplier, String...)</code></a></li> |
| <li><a href="#transformValues(org.apache.kafka.streams.kstream.ValueTransformerSupplier,java.lang.String...)"><code>transformValues(ValueTransformerSupplier, String...)</code></a></li> |
| <li><a href="#transformValues(org.apache.kafka.streams.kstream.ValueTransformerWithKeySupplier,java.lang.String...)"><code>transformValues(ValueTransformerWithKeySupplier, String...)</code></a></li> |
| <li><a href="#flatTransformValues(org.apache.kafka.streams.kstream.ValueTransformerSupplier,java.lang.String...)"><code>flatTransformValues(ValueTransformerSupplier, String...)</code></a></li> |
| <li><a href="#flatTransformValues(org.apache.kafka.streams.kstream.ValueTransformerWithKeySupplier,java.lang.String...)"><code>flatTransformValues(ValueTransformerWithKeySupplier, String...)</code></a></li> |
| </ul> |
| </dd> |
| </dl> |
| </section> |
| </li> |
| <li> |
| <section class="detail" id="print(org.apache.kafka.streams.kstream.Printed)"> |
| <h3>print</h3> |
| <div class="member-signature"><span class="return-type">void</span> <span class="element-name">print</span><wbr><span class="parameters">(<a href="Printed.html" title="class in org.apache.kafka.streams.kstream">Printed</a><<a href="KStream.html" title="type parameter in KStream">K</a>,<wbr><a href="KStream.html" title="type parameter in KStream">V</a>> printed)</span></div> |
| <div class="block">Print the records of this KStream using the options provided by <a href="Printed.html" title="class in org.apache.kafka.streams.kstream"><code>Printed</code></a> |
| Note that this is mainly for debugging/testing purposes, and it will try to flush on each record print. |
| It <em>SHOULD NOT</em> be used for production usage if performance requirements are concerned.</div> |
| <dl class="notes"> |
| <dt>Parameters:</dt> |
| <dd><code>printed</code> - options for printing</dd> |
| </dl> |
| </section> |
| </li> |
| <li> |
| <section class="detail" id="foreach(org.apache.kafka.streams.kstream.ForeachAction)"> |
| <h3>foreach</h3> |
| <div class="member-signature"><span class="return-type">void</span> <span class="element-name">foreach</span><wbr><span class="parameters">(<a href="ForeachAction.html" title="interface in org.apache.kafka.streams.kstream">ForeachAction</a><? super <a href="KStream.html" title="type parameter in KStream">K</a>,<wbr>? super <a href="KStream.html" title="type parameter in KStream">V</a>> action)</span></div> |
| <div class="block">Perform an action on each record of <code>KStream</code>. |
| This is a stateless record-by-record operation (cf. <a href="#process(org.apache.kafka.streams.processor.api.ProcessorSupplier,java.lang.String...)"><code>process(ProcessorSupplier, String...)</code></a>). |
| Note that this is a terminal operation that returns void.</div> |
| <dl class="notes"> |
| <dt>Parameters:</dt> |
| <dd><code>action</code> - an action to perform on each record</dd> |
| <dt>See Also:</dt> |
| <dd> |
| <ul class="see-list-long"> |
| <li><a href="#process(org.apache.kafka.streams.processor.api.ProcessorSupplier,java.lang.String...)"><code>process(ProcessorSupplier, String...)</code></a></li> |
| </ul> |
| </dd> |
| </dl> |
| </section> |
| </li> |
| <li> |
| <section class="detail" id="foreach(org.apache.kafka.streams.kstream.ForeachAction,org.apache.kafka.streams.kstream.Named)"> |
| <h3>foreach</h3> |
| <div class="member-signature"><span class="return-type">void</span> <span class="element-name">foreach</span><wbr><span class="parameters">(<a href="ForeachAction.html" title="interface in org.apache.kafka.streams.kstream">ForeachAction</a><? super <a href="KStream.html" title="type parameter in KStream">K</a>,<wbr>? super <a href="KStream.html" title="type parameter in KStream">V</a>> action, |
| <a href="Named.html" title="class in org.apache.kafka.streams.kstream">Named</a> named)</span></div> |
| <div class="block">Perform an action on each record of <code>KStream</code>. |
| This is a stateless record-by-record operation (cf. <a href="#process(org.apache.kafka.streams.processor.api.ProcessorSupplier,java.lang.String...)"><code>process(ProcessorSupplier, String...)</code></a>). |
| Note that this is a terminal operation that returns void.</div> |
| <dl class="notes"> |
| <dt>Parameters:</dt> |
| <dd><code>action</code> - an action to perform on each record</dd> |
| <dd><code>named</code> - a <a href="Named.html" title="class in org.apache.kafka.streams.kstream"><code>Named</code></a> config used to name the processor in the topology</dd> |
| <dt>See Also:</dt> |
| <dd> |
| <ul class="see-list-long"> |
| <li><a href="#process(org.apache.kafka.streams.processor.api.ProcessorSupplier,java.lang.String...)"><code>process(ProcessorSupplier, String...)</code></a></li> |
| </ul> |
| </dd> |
| </dl> |
| </section> |
| </li> |
| <li> |
| <section class="detail" id="peek(org.apache.kafka.streams.kstream.ForeachAction)"> |
| <h3>peek</h3> |
| <div class="member-signature"><span class="return-type"><a href="KStream.html" title="interface in org.apache.kafka.streams.kstream">KStream</a><<a href="KStream.html" title="type parameter in KStream">K</a>,<wbr><a href="KStream.html" title="type parameter in KStream">V</a>></span> <span class="element-name">peek</span><wbr><span class="parameters">(<a href="ForeachAction.html" title="interface in org.apache.kafka.streams.kstream">ForeachAction</a><? super <a href="KStream.html" title="type parameter in KStream">K</a>,<wbr>? super <a href="KStream.html" title="type parameter in KStream">V</a>> action)</span></div> |
| <div class="block">Perform an action on each record of <code>KStream</code>. |
| This is a stateless record-by-record operation (cf. <a href="#process(org.apache.kafka.streams.processor.api.ProcessorSupplier,java.lang.String...)"><code>process(ProcessorSupplier, String...)</code></a>). |
| <p> |
| Peek is a non-terminal operation that triggers a side effect (such as logging or statistics collection) |
| and returns an unchanged stream. |
| <p> |
| Note that since this operation is stateless, it may execute multiple times for a single record in failure cases.</div> |
| <dl class="notes"> |
| <dt>Parameters:</dt> |
| <dd><code>action</code> - an action to perform on each record</dd> |
| <dt>Returns:</dt> |
| <dd>itself</dd> |
| <dt>See Also:</dt> |
| <dd> |
| <ul class="see-list-long"> |
| <li><a href="#process(org.apache.kafka.streams.processor.api.ProcessorSupplier,java.lang.String...)"><code>process(ProcessorSupplier, String...)</code></a></li> |
| </ul> |
| </dd> |
| </dl> |
| </section> |
| </li> |
| <li> |
| <section class="detail" id="peek(org.apache.kafka.streams.kstream.ForeachAction,org.apache.kafka.streams.kstream.Named)"> |
| <h3>peek</h3> |
| <div class="member-signature"><span class="return-type"><a href="KStream.html" title="interface in org.apache.kafka.streams.kstream">KStream</a><<a href="KStream.html" title="type parameter in KStream">K</a>,<wbr><a href="KStream.html" title="type parameter in KStream">V</a>></span> <span class="element-name">peek</span><wbr><span class="parameters">(<a href="ForeachAction.html" title="interface in org.apache.kafka.streams.kstream">ForeachAction</a><? super <a href="KStream.html" title="type parameter in KStream">K</a>,<wbr>? super <a href="KStream.html" title="type parameter in KStream">V</a>> action, |
| <a href="Named.html" title="class in org.apache.kafka.streams.kstream">Named</a> named)</span></div> |
| <div class="block">Perform an action on each record of <code>KStream</code>. |
| This is a stateless record-by-record operation (cf. <a href="#process(org.apache.kafka.streams.processor.api.ProcessorSupplier,java.lang.String...)"><code>process(ProcessorSupplier, String...)</code></a>). |
| <p> |
| Peek is a non-terminal operation that triggers a side effect (such as logging or statistics collection) |
| and returns an unchanged stream. |
| <p> |
| Note that since this operation is stateless, it may execute multiple times for a single record in failure cases.</div> |
| <dl class="notes"> |
| <dt>Parameters:</dt> |
| <dd><code>action</code> - an action to perform on each record</dd> |
| <dd><code>named</code> - a <a href="Named.html" title="class in org.apache.kafka.streams.kstream"><code>Named</code></a> config used to name the processor in the topology</dd> |
| <dt>Returns:</dt> |
| <dd>itself</dd> |
| <dt>See Also:</dt> |
| <dd> |
| <ul class="see-list-long"> |
| <li><a href="#process(org.apache.kafka.streams.processor.api.ProcessorSupplier,java.lang.String...)"><code>process(ProcessorSupplier, String...)</code></a></li> |
| </ul> |
| </dd> |
| </dl> |
| </section> |
| </li> |
| <li> |
| <section class="detail" id="branch(org.apache.kafka.streams.kstream.Predicate...)"> |
| <h3>branch</h3> |
| <div class="member-signature"><span class="annotations"><a href="https://docs.oracle.com/en/java/javase/17/docs/api/java.base/java/lang/Deprecated.html" title="class or interface in java.lang" class="external-link">@Deprecated</a> |
| </span><span class="return-type"><a href="KStream.html" title="interface in org.apache.kafka.streams.kstream">KStream</a><<a href="KStream.html" title="type parameter in KStream">K</a>,<wbr><a href="KStream.html" title="type parameter in KStream">V</a>>[]</span> <span class="element-name">branch</span><wbr><span class="parameters">(<a href="Predicate.html" title="interface in org.apache.kafka.streams.kstream">Predicate</a><? super <a href="KStream.html" title="type parameter in KStream">K</a>,<wbr>? super <a href="KStream.html" title="type parameter in KStream">V</a>>... predicates)</span></div> |
| <div class="deprecation-block"><span class="deprecated-label">Deprecated.</span> |
| <div class="deprecation-comment">since 2.8. Use <a href="#split()"><code>split()</code></a> instead.</div> |
| </div> |
| <div class="block">Creates an array of <code>KStream</code> from this stream by branching the records in the original stream based on |
| the supplied predicates. |
| Each record is evaluated against the supplied predicates, and predicates are evaluated in order. |
| Each stream in the result array corresponds position-wise (index) to the predicate in the supplied predicates. |
| The branching happens on first-match: A record in the original stream is assigned to the corresponding result |
| stream for the first predicate that evaluates to true, and is assigned to this stream only. |
| A record will be dropped if none of the predicates evaluate to true. |
| This is a stateless record-by-record operation.</div> |
| <dl class="notes"> |
| <dt>Parameters:</dt> |
| <dd><code>predicates</code> - the ordered list of <a href="Predicate.html" title="interface in org.apache.kafka.streams.kstream"><code>Predicate</code></a> instances</dd> |
| <dt>Returns:</dt> |
| <dd>multiple distinct substreams of this <code>KStream</code></dd> |
| </dl> |
| </section> |
| </li> |
| <li> |
| <section class="detail" id="branch(org.apache.kafka.streams.kstream.Named,org.apache.kafka.streams.kstream.Predicate...)"> |
| <h3>branch</h3> |
| <div class="member-signature"><span class="annotations"><a href="https://docs.oracle.com/en/java/javase/17/docs/api/java.base/java/lang/Deprecated.html" title="class or interface in java.lang" class="external-link">@Deprecated</a> |
| </span><span class="return-type"><a href="KStream.html" title="interface in org.apache.kafka.streams.kstream">KStream</a><<a href="KStream.html" title="type parameter in KStream">K</a>,<wbr><a href="KStream.html" title="type parameter in KStream">V</a>>[]</span> <span class="element-name">branch</span><wbr><span class="parameters">(<a href="Named.html" title="class in org.apache.kafka.streams.kstream">Named</a> named, |
| <a href="Predicate.html" title="interface in org.apache.kafka.streams.kstream">Predicate</a><? super <a href="KStream.html" title="type parameter in KStream">K</a>,<wbr>? super <a href="KStream.html" title="type parameter in KStream">V</a>>... predicates)</span></div> |
| <div class="deprecation-block"><span class="deprecated-label">Deprecated.</span> |
| <div class="deprecation-comment">since 2.8. Use <a href="#split(org.apache.kafka.streams.kstream.Named)"><code>split(Named)</code></a> instead.</div> |
| </div> |
| <div class="block">Creates an array of <code>KStream</code> from this stream by branching the records in the original stream based on |
| the supplied predicates. |
| Each record is evaluated against the supplied predicates, and predicates are evaluated in order. |
| Each stream in the result array corresponds position-wise (index) to the predicate in the supplied predicates. |
| The branching happens on first-match: A record in the original stream is assigned to the corresponding result |
| stream for the first predicate that evaluates to true, and is assigned to this stream only. |
| A record will be dropped if none of the predicates evaluate to true. |
| This is a stateless record-by-record operation.</div> |
| <dl class="notes"> |
| <dt>Parameters:</dt> |
| <dd><code>named</code> - a <a href="Named.html" title="class in org.apache.kafka.streams.kstream"><code>Named</code></a> config used to name the processor in the topology</dd> |
| <dd><code>predicates</code> - the ordered list of <a href="Predicate.html" title="interface in org.apache.kafka.streams.kstream"><code>Predicate</code></a> instances</dd> |
| <dt>Returns:</dt> |
| <dd>multiple distinct substreams of this <code>KStream</code></dd> |
| </dl> |
| </section> |
| </li> |
| <li> |
| <section class="detail" id="split()"> |
| <h3>split</h3> |
| <div class="member-signature"><span class="return-type"><a href="BranchedKStream.html" title="interface in org.apache.kafka.streams.kstream">BranchedKStream</a><<a href="KStream.html" title="type parameter in KStream">K</a>,<wbr><a href="KStream.html" title="type parameter in KStream">V</a>></span> <span class="element-name">split</span>()</div> |
| <div class="block">Split this stream into different branches. The returned <a href="BranchedKStream.html" title="interface in org.apache.kafka.streams.kstream"><code>BranchedKStream</code></a> instance can be used for routing |
| the records to different branches depending on evaluation against the supplied predicates. |
| <p> |
| Note: Stream branching is a stateless record-by-record operation. |
| Please check <a href="BranchedKStream.html" title="interface in org.apache.kafka.streams.kstream"><code>BranchedKStream</code></a> for detailed description and usage example</div> |
| <dl class="notes"> |
| <dt>Returns:</dt> |
| <dd><a href="BranchedKStream.html" title="interface in org.apache.kafka.streams.kstream"><code>BranchedKStream</code></a> that provides methods for routing the records to different branches.</dd> |
| </dl> |
| </section> |
| </li> |
| <li> |
| <section class="detail" id="split(org.apache.kafka.streams.kstream.Named)"> |
| <h3>split</h3> |
| <div class="member-signature"><span class="return-type"><a href="BranchedKStream.html" title="interface in org.apache.kafka.streams.kstream">BranchedKStream</a><<a href="KStream.html" title="type parameter in KStream">K</a>,<wbr><a href="KStream.html" title="type parameter in KStream">V</a>></span> <span class="element-name">split</span><wbr><span class="parameters">(<a href="Named.html" title="class in org.apache.kafka.streams.kstream">Named</a> named)</span></div> |
| <div class="block">Split this stream into different branches. The returned <a href="BranchedKStream.html" title="interface in org.apache.kafka.streams.kstream"><code>BranchedKStream</code></a> instance can be used for routing |
| the records to different branches depending on evaluation against the supplied predicates. |
| <p> |
| Note: Stream branching is a stateless record-by-record operation. |
| Please check <a href="BranchedKStream.html" title="interface in org.apache.kafka.streams.kstream"><code>BranchedKStream</code></a> for detailed description and usage example</div> |
| <dl class="notes"> |
| <dt>Parameters:</dt> |
| <dd><code>named</code> - a <a href="Named.html" title="class in org.apache.kafka.streams.kstream"><code>Named</code></a> config used to name the processor in the topology and also to set the name prefix |
| for the resulting branches (see <a href="BranchedKStream.html" title="interface in org.apache.kafka.streams.kstream"><code>BranchedKStream</code></a>)</dd> |
| <dt>Returns:</dt> |
| <dd><a href="BranchedKStream.html" title="interface in org.apache.kafka.streams.kstream"><code>BranchedKStream</code></a> that provides methods for routing the records to different branches.</dd> |
| </dl> |
| </section> |
| </li> |
| <li> |
| <section class="detail" id="merge(org.apache.kafka.streams.kstream.KStream)"> |
| <h3>merge</h3> |
| <div class="member-signature"><span class="return-type"><a href="KStream.html" title="interface in org.apache.kafka.streams.kstream">KStream</a><<a href="KStream.html" title="type parameter in KStream">K</a>,<wbr><a href="KStream.html" title="type parameter in KStream">V</a>></span> <span class="element-name">merge</span><wbr><span class="parameters">(<a href="KStream.html" title="interface in org.apache.kafka.streams.kstream">KStream</a><<a href="KStream.html" title="type parameter in KStream">K</a>,<wbr><a href="KStream.html" title="type parameter in KStream">V</a>> stream)</span></div> |
| <div class="block">Merge this stream and the given stream into one larger stream. |
| <p> |
| There is no ordering guarantee between records from this <code>KStream</code> and records from |
| the provided <code>KStream</code> in the merged stream. |
| Relative order is preserved within each input stream though (ie, records within one input |
| stream are processed in order).</div> |
| <dl class="notes"> |
| <dt>Parameters:</dt> |
| <dd><code>stream</code> - a stream which is to be merged into this stream</dd> |
| <dt>Returns:</dt> |
| <dd>a merged stream containing all records from this and the provided <code>KStream</code></dd> |
| </dl> |
| </section> |
| </li> |
| <li> |
| <section class="detail" id="merge(org.apache.kafka.streams.kstream.KStream,org.apache.kafka.streams.kstream.Named)"> |
| <h3>merge</h3> |
| <div class="member-signature"><span class="return-type"><a href="KStream.html" title="interface in org.apache.kafka.streams.kstream">KStream</a><<a href="KStream.html" title="type parameter in KStream">K</a>,<wbr><a href="KStream.html" title="type parameter in KStream">V</a>></span> <span class="element-name">merge</span><wbr><span class="parameters">(<a href="KStream.html" title="interface in org.apache.kafka.streams.kstream">KStream</a><<a href="KStream.html" title="type parameter in KStream">K</a>,<wbr><a href="KStream.html" title="type parameter in KStream">V</a>> stream, |
| <a href="Named.html" title="class in org.apache.kafka.streams.kstream">Named</a> named)</span></div> |
| <div class="block">Merge this stream and the given stream into one larger stream. |
| <p> |
| There is no ordering guarantee between records from this <code>KStream</code> and records from |
| the provided <code>KStream</code> in the merged stream. |
| Relative order is preserved within each input stream though (ie, records within one input |
| stream are processed in order).</div> |
| <dl class="notes"> |
| <dt>Parameters:</dt> |
| <dd><code>stream</code> - a stream which is to be merged into this stream</dd> |
| <dd><code>named</code> - a <a href="Named.html" title="class in org.apache.kafka.streams.kstream"><code>Named</code></a> config used to name the processor in the topology</dd> |
| <dt>Returns:</dt> |
| <dd>a merged stream containing all records from this and the provided <code>KStream</code></dd> |
| </dl> |
| </section> |
| </li> |
| <li> |
| <section class="detail" id="through(java.lang.String)"> |
| <h3>through</h3> |
| <div class="member-signature"><span class="annotations"><a href="https://docs.oracle.com/en/java/javase/17/docs/api/java.base/java/lang/Deprecated.html" title="class or interface in java.lang" class="external-link">@Deprecated</a> |
| </span><span class="return-type"><a href="KStream.html" title="interface in org.apache.kafka.streams.kstream">KStream</a><<a href="KStream.html" title="type parameter in KStream">K</a>,<wbr><a href="KStream.html" title="type parameter in KStream">V</a>></span> <span class="element-name">through</span><wbr><span class="parameters">(<a href="https://docs.oracle.com/en/java/javase/17/docs/api/java.base/java/lang/String.html" title="class or interface in java.lang" class="external-link">String</a> topic)</span></div> |
| <div class="deprecation-block"><span class="deprecated-label">Deprecated.</span> |
| <div class="deprecation-comment">since 2.6; use <a href="#repartition()"><code>repartition()</code></a> instead</div> |
| </div> |
| <div class="block">Materialize this stream to a topic and creates a new <code>KStream</code> from the topic using default serializers, |
| deserializers, and producer's <code>DefaultPartitioner</code>. |
| The specified topic should be manually created before it is used (i.e., before the Kafka Streams application is |
| started). |
| <p> |
| This is similar to calling <a href="#to(java.lang.String)"><code>#to(someTopicName)</code></a> and |
| <a href="../StreamsBuilder.html#stream(java.lang.String)"><code>StreamsBuilder#stream(someTopicName)</code></a>. |
| Note that <code>through()</code> uses a hard coded <a href="../processor/FailOnInvalidTimestamp.html" title="class in org.apache.kafka.streams.processor"><code>timestamp extractor</code></a> and does not allow to customize it, to ensure correct timestamp propagation.</div> |
| <dl class="notes"> |
| <dt>Parameters:</dt> |
| <dd><code>topic</code> - the topic name</dd> |
| <dt>Returns:</dt> |
| <dd>a <code>KStream</code> that contains the exact same (and potentially repartitioned) records as this <code>KStream</code></dd> |
| </dl> |
| </section> |
| </li> |
| <li> |
| <section class="detail" id="through(java.lang.String,org.apache.kafka.streams.kstream.Produced)"> |
| <h3>through</h3> |
| <div class="member-signature"><span class="annotations"><a href="https://docs.oracle.com/en/java/javase/17/docs/api/java.base/java/lang/Deprecated.html" title="class or interface in java.lang" class="external-link">@Deprecated</a> |
| </span><span class="return-type"><a href="KStream.html" title="interface in org.apache.kafka.streams.kstream">KStream</a><<a href="KStream.html" title="type parameter in KStream">K</a>,<wbr><a href="KStream.html" title="type parameter in KStream">V</a>></span> <span class="element-name">through</span><wbr><span class="parameters">(<a href="https://docs.oracle.com/en/java/javase/17/docs/api/java.base/java/lang/String.html" title="class or interface in java.lang" class="external-link">String</a> topic, |
| <a href="Produced.html" title="class in org.apache.kafka.streams.kstream">Produced</a><<a href="KStream.html" title="type parameter in KStream">K</a>,<wbr><a href="KStream.html" title="type parameter in KStream">V</a>> produced)</span></div> |
| <div class="deprecation-block"><span class="deprecated-label">Deprecated.</span> |
| <div class="deprecation-comment">since 2.6; use <a href="#repartition(org.apache.kafka.streams.kstream.Repartitioned)"><code>repartition(Repartitioned)</code></a> instead</div> |
| </div> |
| <div class="block">Materialize this stream to a topic and creates a new <code>KStream</code> from the topic using the |
| <a href="Produced.html" title="class in org.apache.kafka.streams.kstream"><code>Produced</code></a> instance for configuration of the <a href="../../common/serialization/Serde.html" title="interface in org.apache.kafka.common.serialization"><code>key serde</code></a>, <a href="../../common/serialization/Serde.html" title="interface in org.apache.kafka.common.serialization"><code>value serde</code></a>, |
| and <a href="../processor/StreamPartitioner.html" title="interface in org.apache.kafka.streams.processor"><code>StreamPartitioner</code></a>. |
| The specified topic should be manually created before it is used (i.e., before the Kafka Streams application is |
| started). |
| <p> |
| This is similar to calling <a href="#to(java.lang.String,org.apache.kafka.streams.kstream.Produced)"><code>to(someTopic, Produced.with(keySerde, valueSerde)</code></a> |
| and <a href="../StreamsBuilder.html#stream(java.lang.String,org.apache.kafka.streams.kstream.Consumed)"><code>StreamsBuilder#stream(someTopicName, Consumed.with(keySerde, valueSerde))</code></a>. |
| Note that <code>through()</code> uses a hard coded <a href="../processor/FailOnInvalidTimestamp.html" title="class in org.apache.kafka.streams.processor"><code>timestamp extractor</code></a> and does not allow to customize it, to ensure correct timestamp propagation.</div> |
| <dl class="notes"> |
| <dt>Parameters:</dt> |
| <dd><code>topic</code> - the topic name</dd> |
| <dd><code>produced</code> - the options to use when producing to the topic</dd> |
| <dt>Returns:</dt> |
| <dd>a <code>KStream</code> that contains the exact same (and potentially repartitioned) records as this <code>KStream</code></dd> |
| </dl> |
| </section> |
| </li> |
| <li> |
| <section class="detail" id="repartition()"> |
| <h3>repartition</h3> |
| <div class="member-signature"><span class="return-type"><a href="KStream.html" title="interface in org.apache.kafka.streams.kstream">KStream</a><<a href="KStream.html" title="type parameter in KStream">K</a>,<wbr><a href="KStream.html" title="type parameter in KStream">V</a>></span> <span class="element-name">repartition</span>()</div> |
| <div class="block">Materialize this stream to an auto-generated repartition topic and create a new <code>KStream</code> |
| from the auto-generated topic using default serializers, deserializers, and producer's <code>DefaultPartitioner</code>. |
| The number of partitions is determined based on the upstream topics partition numbers. |
| <p> |
| The created topic is considered as an internal topic and is meant to be used only by the current Kafka Streams instance. |
| Similar to auto-repartitioning, the topic will be created with infinite retention time and data will be automatically purged by Kafka Streams. |
| The topic will be named as "${applicationId}-<name>-repartition", where "applicationId" is user-specified in |
| <a href="../StreamsConfig.html" title="class in org.apache.kafka.streams"><code>StreamsConfig</code></a> via parameter <a href="../StreamsConfig.html#APPLICATION_ID_CONFIG"><code>APPLICATION_ID_CONFIG</code></a>, |
| "<name>" is an internally generated name, and "-repartition" is a fixed suffix.</div> |
| <dl class="notes"> |
| <dt>Returns:</dt> |
| <dd><code>KStream</code> that contains the exact same repartitioned records as this <code>KStream</code>.</dd> |
| </dl> |
| </section> |
| </li> |
| <li> |
| <section class="detail" id="repartition(org.apache.kafka.streams.kstream.Repartitioned)"> |
| <h3>repartition</h3> |
| <div class="member-signature"><span class="return-type"><a href="KStream.html" title="interface in org.apache.kafka.streams.kstream">KStream</a><<a href="KStream.html" title="type parameter in KStream">K</a>,<wbr><a href="KStream.html" title="type parameter in KStream">V</a>></span> <span class="element-name">repartition</span><wbr><span class="parameters">(<a href="Repartitioned.html" title="class in org.apache.kafka.streams.kstream">Repartitioned</a><<a href="KStream.html" title="type parameter in KStream">K</a>,<wbr><a href="KStream.html" title="type parameter in KStream">V</a>> repartitioned)</span></div> |
| <div class="block">Materialize this stream to an auto-generated repartition topic and create a new <code>KStream</code> |
| from the auto-generated topic using <a href="../../common/serialization/Serde.html" title="interface in org.apache.kafka.common.serialization"><code>key serde</code></a>, <a href="../../common/serialization/Serde.html" title="interface in org.apache.kafka.common.serialization"><code>value serde</code></a>, <a href="../processor/StreamPartitioner.html" title="interface in org.apache.kafka.streams.processor"><code>StreamPartitioner</code></a>, |
| number of partitions, and topic name part as defined by <a href="Repartitioned.html" title="class in org.apache.kafka.streams.kstream"><code>Repartitioned</code></a>. |
| <p> |
| The created topic is considered as an internal topic and is meant to be used only by the current Kafka Streams instance. |
| Similar to auto-repartitioning, the topic will be created with infinite retention time and data will be automatically purged by Kafka Streams. |
| The topic will be named as "${applicationId}-<name>-repartition", where "applicationId" is user-specified in |
| <a href="../StreamsConfig.html" title="class in org.apache.kafka.streams"><code>StreamsConfig</code></a> via parameter <a href="../StreamsConfig.html#APPLICATION_ID_CONFIG"><code>APPLICATION_ID_CONFIG</code></a>, |
| "<name>" is either provided via <a href="Repartitioned.html#as(java.lang.String)"><code>Repartitioned.as(String)</code></a> or an internally |
| generated name, and "-repartition" is a fixed suffix.</div> |
| <dl class="notes"> |
| <dt>Parameters:</dt> |
| <dd><code>repartitioned</code> - the <a href="Repartitioned.html" title="class in org.apache.kafka.streams.kstream"><code>Repartitioned</code></a> instance used to specify <a href="../../common/serialization/Serdes.html" title="class in org.apache.kafka.common.serialization"><code>Serdes</code></a>, |
| <a href="../processor/StreamPartitioner.html" title="interface in org.apache.kafka.streams.processor"><code>StreamPartitioner</code></a> which determines how records are distributed among partitions of the topic, |
| part of the topic name, and number of partitions for a repartition topic.</dd> |
| <dt>Returns:</dt> |
| <dd>a <code>KStream</code> that contains the exact same repartitioned records as this <code>KStream</code>.</dd> |
| </dl> |
| </section> |
| </li> |
| <li> |
| <section class="detail" id="to(java.lang.String)"> |
| <h3>to</h3> |
| <div class="member-signature"><span class="return-type">void</span> <span class="element-name">to</span><wbr><span class="parameters">(<a href="https://docs.oracle.com/en/java/javase/17/docs/api/java.base/java/lang/String.html" title="class or interface in java.lang" class="external-link">String</a> topic)</span></div> |
| <div class="block">Materialize this stream to a topic using default serializers specified in the config and producer's |
| <code>DefaultPartitioner</code>. |
| The specified topic should be manually created before it is used (i.e., before the Kafka Streams application is |
| started).</div> |
| <dl class="notes"> |
| <dt>Parameters:</dt> |
| <dd><code>topic</code> - the topic name</dd> |
| </dl> |
| </section> |
| </li> |
| <li> |
| <section class="detail" id="to(java.lang.String,org.apache.kafka.streams.kstream.Produced)"> |
| <h3>to</h3> |
| <div class="member-signature"><span class="return-type">void</span> <span class="element-name">to</span><wbr><span class="parameters">(<a href="https://docs.oracle.com/en/java/javase/17/docs/api/java.base/java/lang/String.html" title="class or interface in java.lang" class="external-link">String</a> topic, |
| <a href="Produced.html" title="class in org.apache.kafka.streams.kstream">Produced</a><<a href="KStream.html" title="type parameter in KStream">K</a>,<wbr><a href="KStream.html" title="type parameter in KStream">V</a>> produced)</span></div> |
| <div class="block">Materialize this stream to a topic using the provided <a href="Produced.html" title="class in org.apache.kafka.streams.kstream"><code>Produced</code></a> instance. |
| The specified topic should be manually created before it is used (i.e., before the Kafka Streams application is |
| started).</div> |
| <dl class="notes"> |
| <dt>Parameters:</dt> |
| <dd><code>topic</code> - the topic name</dd> |
| <dd><code>produced</code> - the options to use when producing to the topic</dd> |
| </dl> |
| </section> |
| </li> |
| <li> |
| <section class="detail" id="to(org.apache.kafka.streams.processor.TopicNameExtractor)"> |
| <h3>to</h3> |
| <div class="member-signature"><span class="return-type">void</span> <span class="element-name">to</span><wbr><span class="parameters">(<a href="../processor/TopicNameExtractor.html" title="interface in org.apache.kafka.streams.processor">TopicNameExtractor</a><<a href="KStream.html" title="type parameter in KStream">K</a>,<wbr><a href="KStream.html" title="type parameter in KStream">V</a>> topicExtractor)</span></div> |
| <div class="block">Dynamically materialize this stream to topics using default serializers specified in the config and producer's |
| <code>DefaultPartitioner</code>. |
| The topic names for each record to send to is dynamically determined based on the <a href="../processor/TopicNameExtractor.html" title="interface in org.apache.kafka.streams.processor"><code>TopicNameExtractor</code></a>.</div> |
| <dl class="notes"> |
| <dt>Parameters:</dt> |
| <dd><code>topicExtractor</code> - the extractor to determine the name of the Kafka topic to write to for each record</dd> |
| </dl> |
| </section> |
| </li> |
| <li> |
| <section class="detail" id="to(org.apache.kafka.streams.processor.TopicNameExtractor,org.apache.kafka.streams.kstream.Produced)"> |
| <h3>to</h3> |
| <div class="member-signature"><span class="return-type">void</span> <span class="element-name">to</span><wbr><span class="parameters">(<a href="../processor/TopicNameExtractor.html" title="interface in org.apache.kafka.streams.processor">TopicNameExtractor</a><<a href="KStream.html" title="type parameter in KStream">K</a>,<wbr><a href="KStream.html" title="type parameter in KStream">V</a>> topicExtractor, |
| <a href="Produced.html" title="class in org.apache.kafka.streams.kstream">Produced</a><<a href="KStream.html" title="type parameter in KStream">K</a>,<wbr><a href="KStream.html" title="type parameter in KStream">V</a>> produced)</span></div> |
| <div class="block">Dynamically materialize this stream to topics using the provided <a href="Produced.html" title="class in org.apache.kafka.streams.kstream"><code>Produced</code></a> instance. |
| The topic names for each record to send to is dynamically determined based on the <a href="../processor/TopicNameExtractor.html" title="interface in org.apache.kafka.streams.processor"><code>TopicNameExtractor</code></a>.</div> |
| <dl class="notes"> |
| <dt>Parameters:</dt> |
| <dd><code>topicExtractor</code> - the extractor to determine the name of the Kafka topic to write to for each record</dd> |
| <dd><code>produced</code> - the options to use when producing to the topic</dd> |
| </dl> |
| </section> |
| </li> |
| <li> |
| <section class="detail" id="toTable()"> |
| <h3>toTable</h3> |
| <div class="member-signature"><span class="return-type"><a href="KTable.html" title="interface in org.apache.kafka.streams.kstream">KTable</a><<a href="KStream.html" title="type parameter in KStream">K</a>,<wbr><a href="KStream.html" title="type parameter in KStream">V</a>></span> <span class="element-name">toTable</span>()</div> |
| <div class="block">Convert this stream to a <a href="KTable.html" title="interface in org.apache.kafka.streams.kstream"><code>KTable</code></a>. |
| <p> |
| If a key changing operator was used before this operation (e.g., <a href="#selectKey(org.apache.kafka.streams.kstream.KeyValueMapper)"><code>selectKey(KeyValueMapper)</code></a>, |
| <a href="#map(org.apache.kafka.streams.kstream.KeyValueMapper)"><code>map(KeyValueMapper)</code></a>, <a href="#flatMap(org.apache.kafka.streams.kstream.KeyValueMapper)"><code>flatMap(KeyValueMapper)</code></a> or |
| <a href="#transform(org.apache.kafka.streams.kstream.TransformerSupplier,java.lang.String...)"><code>transform(TransformerSupplier, String...)</code></a>) an internal repartitioning topic will be created in Kafka. |
| This topic will be named "${applicationId}-<name>-repartition", where "applicationId" is user-specified in |
| <a href="../StreamsConfig.html" title="class in org.apache.kafka.streams"><code>StreamsConfig</code></a> via parameter <a href="../StreamsConfig.html#APPLICATION_ID_CONFIG"><code>APPLICATION_ID_CONFIG</code></a>, |
| "<name>" is an internally generated name, and "-repartition" is a fixed suffix. |
| <p> |
| You can retrieve all generated internal topic names via <a href="../Topology.html#describe()"><code>Topology.describe()</code></a>. |
| <p> |
| For this case, all data of this stream will be redistributed through the repartitioning topic by writing all |
| records to it, and rereading all records from it, such that the resulting <a href="KTable.html" title="interface in org.apache.kafka.streams.kstream"><code>KTable</code></a> is partitioned |
| correctly on its key. |
| Note that you cannot enable <a href="../StreamsConfig.html#TOPOLOGY_OPTIMIZATION_CONFIG"><code>StreamsConfig.TOPOLOGY_OPTIMIZATION_CONFIG</code></a> config for this case, because |
| repartition topics are considered transient and don't allow to recover the result <a href="KTable.html" title="interface in org.apache.kafka.streams.kstream"><code>KTable</code></a> in cause of |
| a failure; hence, a dedicated changelog topic is required to guarantee fault-tolerance. |
| <p> |
| Note that this is a logical operation and only changes the "interpretation" of the stream, i.e., each record of |
| it was a "fact/event" and is re-interpreted as update now (cf. <a href="KStream.html" title="interface in org.apache.kafka.streams.kstream"><code>KStream</code></a> vs <code>KTable</code>).</div> |
| <dl class="notes"> |
| <dt>Returns:</dt> |
| <dd>a <a href="KTable.html" title="interface in org.apache.kafka.streams.kstream"><code>KTable</code></a> that contains the same records as this <code>KStream</code></dd> |
| </dl> |
| </section> |
| </li> |
| <li> |
| <section class="detail" id="toTable(org.apache.kafka.streams.kstream.Named)"> |
| <h3>toTable</h3> |
| <div class="member-signature"><span class="return-type"><a href="KTable.html" title="interface in org.apache.kafka.streams.kstream">KTable</a><<a href="KStream.html" title="type parameter in KStream">K</a>,<wbr><a href="KStream.html" title="type parameter in KStream">V</a>></span> <span class="element-name">toTable</span><wbr><span class="parameters">(<a href="Named.html" title="class in org.apache.kafka.streams.kstream">Named</a> named)</span></div> |
| <div class="block">Convert this stream to a <a href="KTable.html" title="interface in org.apache.kafka.streams.kstream"><code>KTable</code></a>. |
| <p> |
| If a key changing operator was used before this operation (e.g., <a href="#selectKey(org.apache.kafka.streams.kstream.KeyValueMapper)"><code>selectKey(KeyValueMapper)</code></a>, |
| <a href="#map(org.apache.kafka.streams.kstream.KeyValueMapper)"><code>map(KeyValueMapper)</code></a>, <a href="#flatMap(org.apache.kafka.streams.kstream.KeyValueMapper)"><code>flatMap(KeyValueMapper)</code></a> or |
| <a href="#transform(org.apache.kafka.streams.kstream.TransformerSupplier,java.lang.String...)"><code>transform(TransformerSupplier, String...)</code></a>) an internal repartitioning topic will be created in Kafka. |
| This topic will be named "${applicationId}-<name>-repartition", where "applicationId" is user-specified in |
| <a href="../StreamsConfig.html" title="class in org.apache.kafka.streams"><code>StreamsConfig</code></a> via parameter <a href="../StreamsConfig.html#APPLICATION_ID_CONFIG"><code>APPLICATION_ID_CONFIG</code></a>, |
| "<name>" is an internally generated name, and "-repartition" is a fixed suffix. |
| <p> |
| You can retrieve all generated internal topic names via <a href="../Topology.html#describe()"><code>Topology.describe()</code></a>. |
| <p> |
| For this case, all data of this stream will be redistributed through the repartitioning topic by writing all |
| records to it, and rereading all records from it, such that the resulting <a href="KTable.html" title="interface in org.apache.kafka.streams.kstream"><code>KTable</code></a> is partitioned |
| correctly on its key. |
| Note that you cannot enable <a href="../StreamsConfig.html#TOPOLOGY_OPTIMIZATION_CONFIG"><code>StreamsConfig.TOPOLOGY_OPTIMIZATION_CONFIG</code></a> config for this case, because |
| repartition topics are considered transient and don't allow to recover the result <a href="KTable.html" title="interface in org.apache.kafka.streams.kstream"><code>KTable</code></a> in cause of |
| a failure; hence, a dedicated changelog topic is required to guarantee fault-tolerance. |
| <p> |
| Note that this is a logical operation and only changes the "interpretation" of the stream, i.e., each record of |
| it was a "fact/event" and is re-interpreted as update now (cf. <a href="KStream.html" title="interface in org.apache.kafka.streams.kstream"><code>KStream</code></a> vs <code>KTable</code>).</div> |
| <dl class="notes"> |
| <dt>Parameters:</dt> |
| <dd><code>named</code> - a <a href="Named.html" title="class in org.apache.kafka.streams.kstream"><code>Named</code></a> config used to name the processor in the topology</dd> |
| <dt>Returns:</dt> |
| <dd>a <a href="KTable.html" title="interface in org.apache.kafka.streams.kstream"><code>KTable</code></a> that contains the same records as this <code>KStream</code></dd> |
| </dl> |
| </section> |
| </li> |
| <li> |
| <section class="detail" id="toTable(org.apache.kafka.streams.kstream.Materialized)"> |
| <h3>toTable</h3> |
| <div class="member-signature"><span class="return-type"><a href="KTable.html" title="interface in org.apache.kafka.streams.kstream">KTable</a><<a href="KStream.html" title="type parameter in KStream">K</a>,<wbr><a href="KStream.html" title="type parameter in KStream">V</a>></span> <span class="element-name">toTable</span><wbr><span class="parameters">(<a href="Materialized.html" title="class in org.apache.kafka.streams.kstream">Materialized</a><<a href="KStream.html" title="type parameter in KStream">K</a>,<wbr><a href="KStream.html" title="type parameter in KStream">V</a>,<wbr><a href="../state/KeyValueStore.html" title="interface in org.apache.kafka.streams.state">KeyValueStore</a><org.apache.kafka.common.utils.Bytes,<wbr>byte[]>> materialized)</span></div> |
| <div class="block">Convert this stream to a <a href="KTable.html" title="interface in org.apache.kafka.streams.kstream"><code>KTable</code></a>. |
| <p> |
| If a key changing operator was used before this operation (e.g., <a href="#selectKey(org.apache.kafka.streams.kstream.KeyValueMapper)"><code>selectKey(KeyValueMapper)</code></a>, |
| <a href="#map(org.apache.kafka.streams.kstream.KeyValueMapper)"><code>map(KeyValueMapper)</code></a>, <a href="#flatMap(org.apache.kafka.streams.kstream.KeyValueMapper)"><code>flatMap(KeyValueMapper)</code></a> or |
| <a href="#transform(org.apache.kafka.streams.kstream.TransformerSupplier,java.lang.String...)"><code>transform(TransformerSupplier, String...)</code></a>) an internal repartitioning topic will be created in Kafka. |
| This topic will be named "${applicationId}-<name>-repartition", where "applicationId" is user-specified in |
| <a href="../StreamsConfig.html" title="class in org.apache.kafka.streams"><code>StreamsConfig</code></a> via parameter <a href="../StreamsConfig.html#APPLICATION_ID_CONFIG"><code>APPLICATION_ID_CONFIG</code></a>, |
| "<name>" is an internally generated name, and "-repartition" is a fixed suffix. |
| <p> |
| You can retrieve all generated internal topic names via <a href="../Topology.html#describe()"><code>Topology.describe()</code></a>. |
| <p> |
| For this case, all data of this stream will be redistributed through the repartitioning topic by writing all |
| records to it, and rereading all records from it, such that the resulting <a href="KTable.html" title="interface in org.apache.kafka.streams.kstream"><code>KTable</code></a> is partitioned |
| correctly on its key. |
| Note that you cannot enable <a href="../StreamsConfig.html#TOPOLOGY_OPTIMIZATION_CONFIG"><code>StreamsConfig.TOPOLOGY_OPTIMIZATION_CONFIG</code></a> config for this case, because |
| repartition topics are considered transient and don't allow to recover the result <a href="KTable.html" title="interface in org.apache.kafka.streams.kstream"><code>KTable</code></a> in cause of |
| a failure; hence, a dedicated changelog topic is required to guarantee fault-tolerance. |
| <p> |
| Note that this is a logical operation and only changes the "interpretation" of the stream, i.e., each record of |
| it was a "fact/event" and is re-interpreted as update now (cf. <a href="KStream.html" title="interface in org.apache.kafka.streams.kstream"><code>KStream</code></a> vs <code>KTable</code>).</div> |
| <dl class="notes"> |
| <dt>Parameters:</dt> |
| <dd><code>materialized</code> - an instance of <a href="Materialized.html" title="class in org.apache.kafka.streams.kstream"><code>Materialized</code></a> used to describe how the state store of the |
| resulting table should be materialized.</dd> |
| <dt>Returns:</dt> |
| <dd>a <a href="KTable.html" title="interface in org.apache.kafka.streams.kstream"><code>KTable</code></a> that contains the same records as this <code>KStream</code></dd> |
| </dl> |
| </section> |
| </li> |
| <li> |
| <section class="detail" id="toTable(org.apache.kafka.streams.kstream.Named,org.apache.kafka.streams.kstream.Materialized)"> |
| <h3>toTable</h3> |
| <div class="member-signature"><span class="return-type"><a href="KTable.html" title="interface in org.apache.kafka.streams.kstream">KTable</a><<a href="KStream.html" title="type parameter in KStream">K</a>,<wbr><a href="KStream.html" title="type parameter in KStream">V</a>></span> <span class="element-name">toTable</span><wbr><span class="parameters">(<a href="Named.html" title="class in org.apache.kafka.streams.kstream">Named</a> named, |
| <a href="Materialized.html" title="class in org.apache.kafka.streams.kstream">Materialized</a><<a href="KStream.html" title="type parameter in KStream">K</a>,<wbr><a href="KStream.html" title="type parameter in KStream">V</a>,<wbr><a href="../state/KeyValueStore.html" title="interface in org.apache.kafka.streams.state">KeyValueStore</a><org.apache.kafka.common.utils.Bytes,<wbr>byte[]>> materialized)</span></div> |
| <div class="block">Convert this stream to a <a href="KTable.html" title="interface in org.apache.kafka.streams.kstream"><code>KTable</code></a>. |
| <p> |
| If a key changing operator was used before this operation (e.g., <a href="#selectKey(org.apache.kafka.streams.kstream.KeyValueMapper)"><code>selectKey(KeyValueMapper)</code></a>, |
| <a href="#map(org.apache.kafka.streams.kstream.KeyValueMapper)"><code>map(KeyValueMapper)</code></a>, <a href="#flatMap(org.apache.kafka.streams.kstream.KeyValueMapper)"><code>flatMap(KeyValueMapper)</code></a> or |
| <a href="#transform(org.apache.kafka.streams.kstream.TransformerSupplier,java.lang.String...)"><code>transform(TransformerSupplier, String...)</code></a>) an internal repartitioning topic will be created in Kafka. |
| This topic will be named "${applicationId}-<name>-repartition", where "applicationId" is user-specified in |
| <a href="../StreamsConfig.html" title="class in org.apache.kafka.streams"><code>StreamsConfig</code></a> via parameter <a href="../StreamsConfig.html#APPLICATION_ID_CONFIG"><code>APPLICATION_ID_CONFIG</code></a>, |
| "<name>" is an internally generated name, and "-repartition" is a fixed suffix. |
| <p> |
| You can retrieve all generated internal topic names via <a href="../Topology.html#describe()"><code>Topology.describe()</code></a>. |
| <p> |
| For this case, all data of this stream will be redistributed through the repartitioning topic by writing all |
| records to it, and rereading all records from it, such that the resulting <a href="KTable.html" title="interface in org.apache.kafka.streams.kstream"><code>KTable</code></a> is partitioned |
| correctly on its key. |
| Note that you cannot enable <a href="../StreamsConfig.html#TOPOLOGY_OPTIMIZATION_CONFIG"><code>StreamsConfig.TOPOLOGY_OPTIMIZATION_CONFIG</code></a> config for this case, because |
| repartition topics are considered transient and don't allow to recover the result <a href="KTable.html" title="interface in org.apache.kafka.streams.kstream"><code>KTable</code></a> in cause of |
| a failure; hence, a dedicated changelog topic is required to guarantee fault-tolerance. |
| <p> |
| Note that this is a logical operation and only changes the "interpretation" of the stream, i.e., each record of |
| it was a "fact/event" and is re-interpreted as update now (cf. <a href="KStream.html" title="interface in org.apache.kafka.streams.kstream"><code>KStream</code></a> vs <code>KTable</code>).</div> |
| <dl class="notes"> |
| <dt>Parameters:</dt> |
| <dd><code>named</code> - a <a href="Named.html" title="class in org.apache.kafka.streams.kstream"><code>Named</code></a> config used to name the processor in the topology</dd> |
| <dd><code>materialized</code> - an instance of <a href="Materialized.html" title="class in org.apache.kafka.streams.kstream"><code>Materialized</code></a> used to describe how the state store of the |
| resulting table should be materialized.</dd> |
| <dt>Returns:</dt> |
| <dd>a <a href="KTable.html" title="interface in org.apache.kafka.streams.kstream"><code>KTable</code></a> that contains the same records as this <code>KStream</code></dd> |
| </dl> |
| </section> |
| </li> |
| <li> |
| <section class="detail" id="groupBy(org.apache.kafka.streams.kstream.KeyValueMapper)"> |
| <h3>groupBy</h3> |
| <div class="member-signature"><span class="type-parameters"><KR></span> <span class="return-type"><a href="KGroupedStream.html" title="interface in org.apache.kafka.streams.kstream">KGroupedStream</a><KR,<wbr><a href="KStream.html" title="type parameter in KStream">V</a>></span> <span class="element-name">groupBy</span><wbr><span class="parameters">(<a href="KeyValueMapper.html" title="interface in org.apache.kafka.streams.kstream">KeyValueMapper</a><? super <a href="KStream.html" title="type parameter in KStream">K</a>,<wbr>? super <a href="KStream.html" title="type parameter in KStream">V</a>,<wbr>KR> keySelector)</span></div> |
| <div class="block">Group the records of this <code>KStream</code> on a new key that is selected using the provided <a href="KeyValueMapper.html" title="interface in org.apache.kafka.streams.kstream"><code>KeyValueMapper</code></a> |
| and default serializers and deserializers. |
| <a href="KGroupedStream.html" title="interface in org.apache.kafka.streams.kstream"><code>KGroupedStream</code></a> can be further grouped with other streams to form a <a href="CogroupedKStream.html" title="interface in org.apache.kafka.streams.kstream"><code>CogroupedKStream</code></a>. |
| Grouping a stream on the record key is required before an aggregation operator can be applied to the data |
| (cf. <a href="KGroupedStream.html" title="interface in org.apache.kafka.streams.kstream"><code>KGroupedStream</code></a>). |
| The <a href="KeyValueMapper.html" title="interface in org.apache.kafka.streams.kstream"><code>KeyValueMapper</code></a> selects a new key (which may or may not be of the same type) while preserving the |
| original values. |
| If the new record key is <code>null</code> the record will not be included in the resulting <a href="KGroupedStream.html" title="interface in org.apache.kafka.streams.kstream"><code>KGroupedStream</code></a> |
| <p> |
| Because a new key is selected, an internal repartitioning topic may need to be created in Kafka if a |
| later operator depends on the newly selected key. |
| This topic will be named "${applicationId}-<name>-repartition", where "applicationId" is user-specified in |
| <a href="../StreamsConfig.html" title="class in org.apache.kafka.streams"><code>StreamsConfig</code></a> via parameter <a href="../StreamsConfig.html#APPLICATION_ID_CONFIG"><code>APPLICATION_ID_CONFIG</code></a>, |
| "<name>" is an internally generated name, and "-repartition" is a fixed suffix. |
| <p> |
| You can retrieve all generated internal topic names via <a href="../Topology.html#describe()"><code>Topology.describe()</code></a>. |
| <p> |
| All data of this stream will be redistributed through the repartitioning topic by writing all records to it, |
| and rereading all records from it, such that the resulting <a href="KGroupedStream.html" title="interface in org.apache.kafka.streams.kstream"><code>KGroupedStream</code></a> is partitioned on the new key. |
| <p> |
| This operation is equivalent to calling <a href="#selectKey(org.apache.kafka.streams.kstream.KeyValueMapper)"><code>selectKey(KeyValueMapper)</code></a> followed by <a href="#groupByKey()"><code>groupByKey()</code></a>. |
| If the key type is changed, it is recommended to use <a href="#groupBy(org.apache.kafka.streams.kstream.KeyValueMapper,org.apache.kafka.streams.kstream.Grouped)"><code>groupBy(KeyValueMapper, Grouped)</code></a> instead.</div> |
| <dl class="notes"> |
| <dt>Type Parameters:</dt> |
| <dd><code>KR</code> - the key type of the result <a href="KGroupedStream.html" title="interface in org.apache.kafka.streams.kstream"><code>KGroupedStream</code></a></dd> |
| <dt>Parameters:</dt> |
| <dd><code>keySelector</code> - a <a href="KeyValueMapper.html" title="interface in org.apache.kafka.streams.kstream"><code>KeyValueMapper</code></a> that computes a new key for grouping</dd> |
| <dt>Returns:</dt> |
| <dd>a <a href="KGroupedStream.html" title="interface in org.apache.kafka.streams.kstream"><code>KGroupedStream</code></a> that contains the grouped records of the original <code>KStream</code></dd> |
| </dl> |
| </section> |
| </li> |
| <li> |
| <section class="detail" id="groupBy(org.apache.kafka.streams.kstream.KeyValueMapper,org.apache.kafka.streams.kstream.Grouped)"> |
| <h3>groupBy</h3> |
| <div class="member-signature"><span class="type-parameters"><KR></span> <span class="return-type"><a href="KGroupedStream.html" title="interface in org.apache.kafka.streams.kstream">KGroupedStream</a><KR,<wbr><a href="KStream.html" title="type parameter in KStream">V</a>></span> <span class="element-name">groupBy</span><wbr><span class="parameters">(<a href="KeyValueMapper.html" title="interface in org.apache.kafka.streams.kstream">KeyValueMapper</a><? super <a href="KStream.html" title="type parameter in KStream">K</a>,<wbr>? super <a href="KStream.html" title="type parameter in KStream">V</a>,<wbr>KR> keySelector, |
| <a href="Grouped.html" title="class in org.apache.kafka.streams.kstream">Grouped</a><KR,<wbr><a href="KStream.html" title="type parameter in KStream">V</a>> grouped)</span></div> |
| <div class="block">Group the records of this <code>KStream</code> on a new key that is selected using the provided <a href="KeyValueMapper.html" title="interface in org.apache.kafka.streams.kstream"><code>KeyValueMapper</code></a> |
| and <a href="../../common/serialization/Serde.html" title="interface in org.apache.kafka.common.serialization"><code>Serde</code></a>s as specified by <a href="Grouped.html" title="class in org.apache.kafka.streams.kstream"><code>Grouped</code></a>. |
| <a href="KGroupedStream.html" title="interface in org.apache.kafka.streams.kstream"><code>KGroupedStream</code></a> can be further grouped with other streams to form a <a href="CogroupedKStream.html" title="interface in org.apache.kafka.streams.kstream"><code>CogroupedKStream</code></a>. |
| Grouping a stream on the record key is required before an aggregation operator can be applied to the data |
| (cf. <a href="KGroupedStream.html" title="interface in org.apache.kafka.streams.kstream"><code>KGroupedStream</code></a>). |
| The <a href="KeyValueMapper.html" title="interface in org.apache.kafka.streams.kstream"><code>KeyValueMapper</code></a> selects a new key (which may or may not be of the same type) while preserving the |
| original values. |
| If the new record key is <code>null</code> the record will not be included in the resulting <a href="KGroupedStream.html" title="interface in org.apache.kafka.streams.kstream"><code>KGroupedStream</code></a>. |
| <p> |
| Because a new key is selected, an internal repartitioning topic may need to be created in Kafka if a later |
| operator depends on the newly selected key. |
| This topic will be named "${applicationId}-<name>-repartition", where "applicationId" is user-specified in |
| <a href="../StreamsConfig.html" title="class in org.apache.kafka.streams"><code>StreamsConfig</code></a> via parameter <a href="../StreamsConfig.html#APPLICATION_ID_CONFIG"><code>APPLICATION_ID_CONFIG</code></a>, |
| "<name>" is either provided via <a href="Grouped.html#as(java.lang.String)"><code>Grouped.as(String)</code></a> or an |
| internally generated name. |
| <p> |
| You can retrieve all generated internal topic names via <a href="../Topology.html#describe()"><code>Topology.describe()</code></a>. |
| <p> |
| All data of this stream will be redistributed through the repartitioning topic by writing all records to it, |
| and rereading all records from it, such that the resulting <a href="KGroupedStream.html" title="interface in org.apache.kafka.streams.kstream"><code>KGroupedStream</code></a> is partitioned on the new key. |
| <p> |
| This operation is equivalent to calling <a href="#selectKey(org.apache.kafka.streams.kstream.KeyValueMapper)"><code>selectKey(KeyValueMapper)</code></a> followed by <a href="#groupByKey()"><code>groupByKey()</code></a>.</div> |
| <dl class="notes"> |
| <dt>Type Parameters:</dt> |
| <dd><code>KR</code> - the key type of the result <a href="KGroupedStream.html" title="interface in org.apache.kafka.streams.kstream"><code>KGroupedStream</code></a></dd> |
| <dt>Parameters:</dt> |
| <dd><code>keySelector</code> - a <a href="KeyValueMapper.html" title="interface in org.apache.kafka.streams.kstream"><code>KeyValueMapper</code></a> that computes a new key for grouping</dd> |
| <dd><code>grouped</code> - the <a href="Grouped.html" title="class in org.apache.kafka.streams.kstream"><code>Grouped</code></a> instance used to specify <a href="../../common/serialization/Serdes.html" title="class in org.apache.kafka.common.serialization"><code>Serdes</code></a> |
| and part of the name for a repartition topic if repartitioning is required.</dd> |
| <dt>Returns:</dt> |
| <dd>a <a href="KGroupedStream.html" title="interface in org.apache.kafka.streams.kstream"><code>KGroupedStream</code></a> that contains the grouped records of the original <code>KStream</code></dd> |
| </dl> |
| </section> |
| </li> |
| <li> |
| <section class="detail" id="groupByKey()"> |
| <h3>groupByKey</h3> |
| <div class="member-signature"><span class="return-type"><a href="KGroupedStream.html" title="interface in org.apache.kafka.streams.kstream">KGroupedStream</a><<a href="KStream.html" title="type parameter in KStream">K</a>,<wbr><a href="KStream.html" title="type parameter in KStream">V</a>></span> <span class="element-name">groupByKey</span>()</div> |
| <div class="block">Group the records by their current key into a <a href="KGroupedStream.html" title="interface in org.apache.kafka.streams.kstream"><code>KGroupedStream</code></a> while preserving the original values |
| and default serializers and deserializers. |
| <a href="KGroupedStream.html" title="interface in org.apache.kafka.streams.kstream"><code>KGroupedStream</code></a> can be further grouped with other streams to form a <a href="CogroupedKStream.html" title="interface in org.apache.kafka.streams.kstream"><code>CogroupedKStream</code></a>. |
| Grouping a stream on the record key is required before an aggregation operator can be applied to the data |
| (cf. <a href="KGroupedStream.html" title="interface in org.apache.kafka.streams.kstream"><code>KGroupedStream</code></a>). |
| If a record key is <code>null</code> the record will not be included in the resulting <a href="KGroupedStream.html" title="interface in org.apache.kafka.streams.kstream"><code>KGroupedStream</code></a>. |
| <p> |
| If a key changing operator was used before this operation (e.g., <a href="#selectKey(org.apache.kafka.streams.kstream.KeyValueMapper)"><code>selectKey(KeyValueMapper)</code></a>, |
| <a href="#map(org.apache.kafka.streams.kstream.KeyValueMapper)"><code>map(KeyValueMapper)</code></a>, <a href="#flatMap(org.apache.kafka.streams.kstream.KeyValueMapper)"><code>flatMap(KeyValueMapper)</code></a> or |
| <a href="#transform(org.apache.kafka.streams.kstream.TransformerSupplier,java.lang.String...)"><code>transform(TransformerSupplier, String...)</code></a>) an internal repartitioning topic may need to be created in |
| Kafka if a later operator depends on the newly selected key. |
| This topic will be named "${applicationId}-<name>-repartition", where "applicationId" is user-specified in |
| <a href="../StreamsConfig.html" title="class in org.apache.kafka.streams"><code>StreamsConfig</code></a> via parameter <a href="../StreamsConfig.html#APPLICATION_ID_CONFIG"><code>APPLICATION_ID_CONFIG</code></a>, |
| "<name>" is an internally generated name, and "-repartition" is a fixed suffix. |
| <p> |
| You can retrieve all generated internal topic names via <a href="../Topology.html#describe()"><code>Topology.describe()</code></a>. |
| <p> |
| For this case, all data of this stream will be redistributed through the repartitioning topic by writing all |
| records to it, and rereading all records from it, such that the resulting <a href="KGroupedStream.html" title="interface in org.apache.kafka.streams.kstream"><code>KGroupedStream</code></a> is partitioned |
| correctly on its key. |
| If the last key changing operator changed the key type, it is recommended to use |
| <a href="#groupByKey(org.apache.kafka.streams.kstream.Grouped)"><code>groupByKey(org.apache.kafka.streams.kstream.Grouped)</code></a> instead.</div> |
| <dl class="notes"> |
| <dt>Returns:</dt> |
| <dd>a <a href="KGroupedStream.html" title="interface in org.apache.kafka.streams.kstream"><code>KGroupedStream</code></a> that contains the grouped records of the original <code>KStream</code></dd> |
| <dt>See Also:</dt> |
| <dd> |
| <ul class="see-list"> |
| <li><a href="#groupBy(org.apache.kafka.streams.kstream.KeyValueMapper)"><code>groupBy(KeyValueMapper)</code></a></li> |
| </ul> |
| </dd> |
| </dl> |
| </section> |
| </li> |
| <li> |
| <section class="detail" id="groupByKey(org.apache.kafka.streams.kstream.Grouped)"> |
| <h3>groupByKey</h3> |
| <div class="member-signature"><span class="return-type"><a href="KGroupedStream.html" title="interface in org.apache.kafka.streams.kstream">KGroupedStream</a><<a href="KStream.html" title="type parameter in KStream">K</a>,<wbr><a href="KStream.html" title="type parameter in KStream">V</a>></span> <span class="element-name">groupByKey</span><wbr><span class="parameters">(<a href="Grouped.html" title="class in org.apache.kafka.streams.kstream">Grouped</a><<a href="KStream.html" title="type parameter in KStream">K</a>,<wbr><a href="KStream.html" title="type parameter in KStream">V</a>> grouped)</span></div> |
| <div class="block">Group the records by their current key into a <a href="KGroupedStream.html" title="interface in org.apache.kafka.streams.kstream"><code>KGroupedStream</code></a> while preserving the original values |
| and using the serializers as defined by <a href="Grouped.html" title="class in org.apache.kafka.streams.kstream"><code>Grouped</code></a>. |
| <a href="KGroupedStream.html" title="interface in org.apache.kafka.streams.kstream"><code>KGroupedStream</code></a> can be further grouped with other streams to form a <a href="CogroupedKStream.html" title="interface in org.apache.kafka.streams.kstream"><code>CogroupedKStream</code></a>. |
| Grouping a stream on the record key is required before an aggregation operator can be applied to the data |
| (cf. <a href="KGroupedStream.html" title="interface in org.apache.kafka.streams.kstream"><code>KGroupedStream</code></a>). |
| If a record key is <code>null</code> the record will not be included in the resulting <a href="KGroupedStream.html" title="interface in org.apache.kafka.streams.kstream"><code>KGroupedStream</code></a>. |
| <p> |
| If a key changing operator was used before this operation (e.g., <a href="#selectKey(org.apache.kafka.streams.kstream.KeyValueMapper)"><code>selectKey(KeyValueMapper)</code></a>, |
| <a href="#map(org.apache.kafka.streams.kstream.KeyValueMapper)"><code>map(KeyValueMapper)</code></a>, <a href="#flatMap(org.apache.kafka.streams.kstream.KeyValueMapper)"><code>flatMap(KeyValueMapper)</code></a> or |
| <a href="#transform(org.apache.kafka.streams.kstream.TransformerSupplier,java.lang.String...)"><code>transform(TransformerSupplier, String...)</code></a>) an internal repartitioning topic may need to be created in |
| Kafka if a later operator depends on the newly selected key. |
| This topic will be named "${applicationId}-<name>-repartition", where "applicationId" is user-specified in |
| <a href="../StreamsConfig.html" title="class in org.apache.kafka.streams"><code>StreamsConfig</code></a> via parameter <a href="../StreamsConfig.html#APPLICATION_ID_CONFIG"><code>APPLICATION_ID_CONFIG</code></a>, |
| <name> is either provided via <a href="Grouped.html#as(java.lang.String)"><code>Grouped.as(String)</code></a> or an internally |
| generated name, and "-repartition" is a fixed suffix. |
| <p> |
| You can retrieve all generated internal topic names via <a href="../Topology.html#describe()"><code>Topology.describe()</code></a>. |
| <p> |
| For this case, all data of this stream will be redistributed through the repartitioning topic by writing all |
| records to it, and rereading all records from it, such that the resulting <a href="KGroupedStream.html" title="interface in org.apache.kafka.streams.kstream"><code>KGroupedStream</code></a> is partitioned |
| correctly on its key.</div> |
| <dl class="notes"> |
| <dt>Parameters:</dt> |
| <dd><code>grouped</code> - the <a href="Grouped.html" title="class in org.apache.kafka.streams.kstream"><code>Grouped</code></a> instance used to specify <a href="../../common/serialization/Serdes.html" title="class in org.apache.kafka.common.serialization"><code>Serdes</code></a> |
| and part of the name for a repartition topic if repartitioning is required.</dd> |
| <dt>Returns:</dt> |
| <dd>a <a href="KGroupedStream.html" title="interface in org.apache.kafka.streams.kstream"><code>KGroupedStream</code></a> that contains the grouped records of the original <code>KStream</code></dd> |
| <dt>See Also:</dt> |
| <dd> |
| <ul class="see-list"> |
| <li><a href="#groupBy(org.apache.kafka.streams.kstream.KeyValueMapper)"><code>groupBy(KeyValueMapper)</code></a></li> |
| </ul> |
| </dd> |
| </dl> |
| </section> |
| </li> |
| <li> |
| <section class="detail" id="join(org.apache.kafka.streams.kstream.KStream,org.apache.kafka.streams.kstream.ValueJoiner,org.apache.kafka.streams.kstream.JoinWindows)"> |
| <h3>join</h3> |
| <div class="member-signature"><span class="type-parameters"><VO,<wbr> |
| VR></span> <span class="return-type"><a href="KStream.html" title="interface in org.apache.kafka.streams.kstream">KStream</a><<a href="KStream.html" title="type parameter in KStream">K</a>,<wbr>VR></span> <span class="element-name">join</span><wbr><span class="parameters">(<a href="KStream.html" title="interface in org.apache.kafka.streams.kstream">KStream</a><<a href="KStream.html" title="type parameter in KStream">K</a>,<wbr>VO> otherStream, |
| <a href="ValueJoiner.html" title="interface in org.apache.kafka.streams.kstream">ValueJoiner</a><? super <a href="KStream.html" title="type parameter in KStream">V</a>,<wbr>? super VO,<wbr>? extends VR> joiner, |
| <a href="JoinWindows.html" title="class in org.apache.kafka.streams.kstream">JoinWindows</a> windows)</span></div> |
| <div class="block">Join records of this stream with another <code>KStream</code>'s records using windowed inner equi join with default |
| serializers and deserializers. |
| The join is computed on the records' key with join attribute <code>thisKStream.key == otherKStream.key</code>. |
| Furthermore, two records are only joined if their timestamps are close to each other as defined by the given |
| <a href="JoinWindows.html" title="class in org.apache.kafka.streams.kstream"><code>JoinWindows</code></a>, i.e., the window defines an additional join predicate on the record timestamps. |
| <p> |
| For each pair of records meeting both join predicates the provided <a href="ValueJoiner.html" title="interface in org.apache.kafka.streams.kstream"><code>ValueJoiner</code></a> will be called to compute |
| a value (with arbitrary type) for the result record. |
| The key of the result record is the same as for both joining input records. |
| If an input record key or value is <code>null</code> the record will not be included in the join operation and thus no |
| output record will be added to the resulting <code>KStream</code>. |
| <p> |
| Example (assuming all input records belong to the correct windows): |
| <table border='1'> |
| <tr> |
| <th>this</th> |
| <th>other</th> |
| <th>result</th> |
| </tr> |
| <tr> |
| <td><K1:A></td> |
| <td></td> |
| <td></td> |
| </tr> |
| <tr> |
| <td><K2:B></td> |
| <td><K2:b></td> |
| <td><K2:ValueJoiner(B,b)></td> |
| </tr> |
| <tr> |
| <td></td> |
| <td><K3:c></td> |
| <td></td> |
| </tr> |
| </table> |
| Both input streams (or to be more precise, their underlying source topics) need to have the same number of |
| partitions. |
| If this is not the case, you would need to call <a href="#repartition(org.apache.kafka.streams.kstream.Repartitioned)"><code>repartition(Repartitioned)</code></a> (for one input stream) before |
| doing the join and specify the "correct" number of partitions via <a href="Repartitioned.html" title="class in org.apache.kafka.streams.kstream"><code>Repartitioned</code></a> parameter. |
| Furthermore, both input streams need to be co-partitioned on the join key (i.e., use the same partitioner). |
| If this requirement is not met, Kafka Streams will automatically repartition the data, i.e., it will create an |
| internal repartitioning topic in Kafka and write and re-read the data via this topic before the actual join. |
| The repartitioning topic will be named "${applicationId}-<name>-repartition", where "applicationId" is |
| user-specified in <a href="../StreamsConfig.html" title="class in org.apache.kafka.streams"><code>StreamsConfig</code></a> via parameter |
| <a href="../StreamsConfig.html#APPLICATION_ID_CONFIG"><code>APPLICATION_ID_CONFIG</code></a>, "<name>" is an internally generated |
| name, and "-repartition" is a fixed suffix. |
| <p> |
| Repartitioning can happen for one or both of the joining <code>KStream</code>s. |
| For this case, all data of the stream will be redistributed through the repartitioning topic by writing all |
| records to it, and rereading all records from it, such that the join input <code>KStream</code> is partitioned |
| correctly on its key. |
| <p> |
| Both of the joining <code>KStream</code>s will be materialized in local state stores with auto-generated store names. |
| For failure and recovery each store will be backed by an internal changelog topic that will be created in Kafka. |
| The changelog topic will be named "${applicationId}-<storename>-changelog", where "applicationId" is user-specified |
| in <a href="../StreamsConfig.html" title="class in org.apache.kafka.streams"><code>StreamsConfig</code></a> via parameter |
| <a href="../StreamsConfig.html#APPLICATION_ID_CONFIG"><code>APPLICATION_ID_CONFIG</code></a>, "storeName" is an |
| internally generated name, and "-changelog" is a fixed suffix. |
| <p> |
| You can retrieve all generated internal topic names via <a href="../Topology.html#describe()"><code>Topology.describe()</code></a>.</div> |
| <dl class="notes"> |
| <dt>Type Parameters:</dt> |
| <dd><code>VO</code> - the value type of the other stream</dd> |
| <dd><code>VR</code> - the value type of the result stream</dd> |
| <dt>Parameters:</dt> |
| <dd><code>otherStream</code> - the <code>KStream</code> to be joined with this stream</dd> |
| <dd><code>joiner</code> - a <a href="ValueJoiner.html" title="interface in org.apache.kafka.streams.kstream"><code>ValueJoiner</code></a> that computes the join result for a pair of matching records</dd> |
| <dd><code>windows</code> - the specification of the <a href="JoinWindows.html" title="class in org.apache.kafka.streams.kstream"><code>JoinWindows</code></a></dd> |
| <dt>Returns:</dt> |
| <dd>a <code>KStream</code> that contains join-records for each key and values computed by the given |
| <a href="ValueJoiner.html" title="interface in org.apache.kafka.streams.kstream"><code>ValueJoiner</code></a>, one for each matched record-pair with the same key and within the joining window intervals</dd> |
| <dt>See Also:</dt> |
| <dd> |
| <ul class="see-list-long"> |
| <li><a href="#leftJoin(org.apache.kafka.streams.kstream.KStream,org.apache.kafka.streams.kstream.ValueJoiner,org.apache.kafka.streams.kstream.JoinWindows)"><code>leftJoin(KStream, ValueJoiner, JoinWindows)</code></a></li> |
| <li><a href="#outerJoin(org.apache.kafka.streams.kstream.KStream,org.apache.kafka.streams.kstream.ValueJoiner,org.apache.kafka.streams.kstream.JoinWindows)"><code>outerJoin(KStream, ValueJoiner, JoinWindows)</code></a></li> |
| </ul> |
| </dd> |
| </dl> |
| </section> |
| </li> |
| <li> |
| <section class="detail" id="join(org.apache.kafka.streams.kstream.KStream,org.apache.kafka.streams.kstream.ValueJoinerWithKey,org.apache.kafka.streams.kstream.JoinWindows)"> |
| <h3>join</h3> |
| <div class="member-signature"><span class="type-parameters"><VO,<wbr> |
| VR></span> <span class="return-type"><a href="KStream.html" title="interface in org.apache.kafka.streams.kstream">KStream</a><<a href="KStream.html" title="type parameter in KStream">K</a>,<wbr>VR></span> <span class="element-name">join</span><wbr><span class="parameters">(<a href="KStream.html" title="interface in org.apache.kafka.streams.kstream">KStream</a><<a href="KStream.html" title="type parameter in KStream">K</a>,<wbr>VO> otherStream, |
| <a href="ValueJoinerWithKey.html" title="interface in org.apache.kafka.streams.kstream">ValueJoinerWithKey</a><? super <a href="KStream.html" title="type parameter in KStream">K</a>,<wbr>? super <a href="KStream.html" title="type parameter in KStream">V</a>,<wbr>? super VO,<wbr>? extends VR> joiner, |
| <a href="JoinWindows.html" title="class in org.apache.kafka.streams.kstream">JoinWindows</a> windows)</span></div> |
| <div class="block">Join records of this stream with another <code>KStream</code>'s records using windowed inner equi join with default |
| serializers and deserializers. |
| The join is computed on the records' key with join attribute <code>thisKStream.key == otherKStream.key</code>. |
| Furthermore, two records are only joined if their timestamps are close to each other as defined by the given |
| <a href="JoinWindows.html" title="class in org.apache.kafka.streams.kstream"><code>JoinWindows</code></a>, i.e., the window defines an additional join predicate on the record timestamps. |
| <p> |
| For each pair of records meeting both join predicates the provided <a href="ValueJoinerWithKey.html" title="interface in org.apache.kafka.streams.kstream"><code>ValueJoinerWithKey</code></a> will be called to compute |
| a value (with arbitrary type) for the result record. |
| Note that the key is read-only and should not be modified, as this can lead to undefined behaviour. |
| The key of the result record is the same as for both joining input records. |
| If an input record key or value is <code>null</code> the record will not be included in the join operation and thus no |
| output record will be added to the resulting <code>KStream</code>. |
| <p> |
| Example (assuming all input records belong to the correct windows): |
| <table border='1'> |
| <tr> |
| <th>this</th> |
| <th>other</th> |
| <th>result</th> |
| </tr> |
| <tr> |
| <td><K1:A></td> |
| <td></td> |
| <td></td> |
| </tr> |
| <tr> |
| <td><K2:B></td> |
| <td><K2:b></td> |
| <td><K2:ValueJoinerWithKey(K1,B,b)></td> |
| </tr> |
| <tr> |
| <td></td> |
| <td><K3:c></td> |
| <td></td> |
| </tr> |
| </table> |
| Both input streams (or to be more precise, their underlying source topics) need to have the same number of |
| partitions. |
| If this is not the case, you would need to call <a href="#repartition(org.apache.kafka.streams.kstream.Repartitioned)"><code>repartition(Repartitioned)</code></a> (for one input stream) before |
| doing the join and specify the "correct" number of partitions via <a href="Repartitioned.html" title="class in org.apache.kafka.streams.kstream"><code>Repartitioned</code></a> parameter. |
| Furthermore, both input streams need to be co-partitioned on the join key (i.e., use the same partitioner). |
| If this requirement is not met, Kafka Streams will automatically repartition the data, i.e., it will create an |
| internal repartitioning topic in Kafka and write and re-read the data via this topic before the actual join. |
| The repartitioning topic will be named "${applicationId}-<name>-repartition", where "applicationId" is |
| user-specified in <a href="../StreamsConfig.html" title="class in org.apache.kafka.streams"><code>StreamsConfig</code></a> via parameter |
| <a href="../StreamsConfig.html#APPLICATION_ID_CONFIG"><code>APPLICATION_ID_CONFIG</code></a>, "<name>" is an internally generated |
| name, and "-repartition" is a fixed suffix. |
| <p> |
| Repartitioning can happen for one or both of the joining <code>KStream</code>s. |
| For this case, all data of the stream will be redistributed through the repartitioning topic by writing all |
| records to it, and rereading all records from it, such that the join input <code>KStream</code> is partitioned |
| correctly on its key. |
| <p> |
| Both of the joining <code>KStream</code>s will be materialized in local state stores with auto-generated store names. |
| For failure and recovery each store will be backed by an internal changelog topic that will be created in Kafka. |
| The changelog topic will be named "${applicationId}-<storename>-changelog", where "applicationId" is user-specified |
| in <a href="../StreamsConfig.html" title="class in org.apache.kafka.streams"><code>StreamsConfig</code></a> via parameter |
| <a href="../StreamsConfig.html#APPLICATION_ID_CONFIG"><code>APPLICATION_ID_CONFIG</code></a>, "storeName" is an |
| internally generated name, and "-changelog" is a fixed suffix. |
| <p> |
| You can retrieve all generated internal topic names via <a href="../Topology.html#describe()"><code>Topology.describe()</code></a>.</div> |
| <dl class="notes"> |
| <dt>Type Parameters:</dt> |
| <dd><code>VO</code> - the value type of the other stream</dd> |
| <dd><code>VR</code> - the value type of the result stream</dd> |
| <dt>Parameters:</dt> |
| <dd><code>otherStream</code> - the <code>KStream</code> to be joined with this stream</dd> |
| <dd><code>joiner</code> - a <a href="ValueJoinerWithKey.html" title="interface in org.apache.kafka.streams.kstream"><code>ValueJoinerWithKey</code></a> that computes the join result for a pair of matching records</dd> |
| <dd><code>windows</code> - the specification of the <a href="JoinWindows.html" title="class in org.apache.kafka.streams.kstream"><code>JoinWindows</code></a></dd> |
| <dt>Returns:</dt> |
| <dd>a <code>KStream</code> that contains join-records for each key and values computed by the given |
| <a href="ValueJoinerWithKey.html" title="interface in org.apache.kafka.streams.kstream"><code>ValueJoinerWithKey</code></a>, one for each matched record-pair with the same key and within the joining window intervals</dd> |
| <dt>See Also:</dt> |
| <dd> |
| <ul class="see-list-long"> |
| <li><a href="#leftJoin(org.apache.kafka.streams.kstream.KStream,org.apache.kafka.streams.kstream.ValueJoinerWithKey,org.apache.kafka.streams.kstream.JoinWindows)"><code>leftJoin(KStream, ValueJoinerWithKey, JoinWindows)</code></a></li> |
| <li><a href="#outerJoin(org.apache.kafka.streams.kstream.KStream,org.apache.kafka.streams.kstream.ValueJoinerWithKey,org.apache.kafka.streams.kstream.JoinWindows)"><code>outerJoin(KStream, ValueJoinerWithKey, JoinWindows)</code></a></li> |
| </ul> |
| </dd> |
| </dl> |
| </section> |
| </li> |
| <li> |
| <section class="detail" id="join(org.apache.kafka.streams.kstream.KStream,org.apache.kafka.streams.kstream.ValueJoiner,org.apache.kafka.streams.kstream.JoinWindows,org.apache.kafka.streams.kstream.StreamJoined)"> |
| <h3>join</h3> |
| <div class="member-signature"><span class="type-parameters"><VO,<wbr> |
| VR></span> <span class="return-type"><a href="KStream.html" title="interface in org.apache.kafka.streams.kstream">KStream</a><<a href="KStream.html" title="type parameter in KStream">K</a>,<wbr>VR></span> <span class="element-name">join</span><wbr><span class="parameters">(<a href="KStream.html" title="interface in org.apache.kafka.streams.kstream">KStream</a><<a href="KStream.html" title="type parameter in KStream">K</a>,<wbr>VO> otherStream, |
| <a href="ValueJoiner.html" title="interface in org.apache.kafka.streams.kstream">ValueJoiner</a><? super <a href="KStream.html" title="type parameter in KStream">V</a>,<wbr>? super VO,<wbr>? extends VR> joiner, |
| <a href="JoinWindows.html" title="class in org.apache.kafka.streams.kstream">JoinWindows</a> windows, |
| <a href="StreamJoined.html" title="class in org.apache.kafka.streams.kstream">StreamJoined</a><<a href="KStream.html" title="type parameter in KStream">K</a>,<wbr><a href="KStream.html" title="type parameter in KStream">V</a>,<wbr>VO> streamJoined)</span></div> |
| <div class="block">Join records of this stream with another <code>KStream</code>'s records using windowed inner equi join using the |
| <a href="StreamJoined.html" title="class in org.apache.kafka.streams.kstream"><code>StreamJoined</code></a> instance for configuration of the <a href="../../common/serialization/Serde.html" title="interface in org.apache.kafka.common.serialization"><code>key serde</code></a>, <a href="../../common/serialization/Serde.html" title="interface in org.apache.kafka.common.serialization"><code>this stream's value |
| serde</code></a>, <a href="../../common/serialization/Serde.html" title="interface in org.apache.kafka.common.serialization"><code>the other stream's value serde</code></a>, and used state stores. |
| The join is computed on the records' key with join attribute <code>thisKStream.key == otherKStream.key</code>. |
| Furthermore, two records are only joined if their timestamps are close to each other as defined by the given |
| <a href="JoinWindows.html" title="class in org.apache.kafka.streams.kstream"><code>JoinWindows</code></a>, i.e., the window defines an additional join predicate on the record timestamps. |
| <p> |
| For each pair of records meeting both join predicates the provided <a href="ValueJoiner.html" title="interface in org.apache.kafka.streams.kstream"><code>ValueJoiner</code></a> will be called to compute |
| a value (with arbitrary type) for the result record. |
| The key of the result record is the same as for both joining input records. |
| If an input record key or value is <code>null</code> the record will not be included in the join operation and thus no |
| output record will be added to the resulting <code>KStream</code>. |
| <p> |
| Example (assuming all input records belong to the correct windows): |
| <table border='1'> |
| <tr> |
| <th>this</th> |
| <th>other</th> |
| <th>result</th> |
| </tr> |
| <tr> |
| <td><K1:A></td> |
| <td></td> |
| <td></td> |
| </tr> |
| <tr> |
| <td><K2:B></td> |
| <td><K2:b></td> |
| <td><K2:ValueJoiner(B,b)></td> |
| </tr> |
| <tr> |
| <td></td> |
| <td><K3:c></td> |
| <td></td> |
| </tr> |
| </table> |
| Both input streams (or to be more precise, their underlying source topics) need to have the same number of |
| partitions. |
| If this is not the case, you would need to call <a href="#repartition(org.apache.kafka.streams.kstream.Repartitioned)"><code>repartition(Repartitioned)</code></a> (for one input stream) before |
| doing the join and specify the "correct" number of partitions via <a href="Repartitioned.html" title="class in org.apache.kafka.streams.kstream"><code>Repartitioned</code></a> parameter. |
| Furthermore, both input streams need to be co-partitioned on the join key (i.e., use the same partitioner). |
| If this requirement is not met, Kafka Streams will automatically repartition the data, i.e., it will create an |
| internal repartitioning topic in Kafka and write and re-read the data via this topic before the actual join. |
| The repartitioning topic will be named "${applicationId}-<name>-repartition", where "applicationId" is |
| user-specified in <a href="../StreamsConfig.html" title="class in org.apache.kafka.streams"><code>StreamsConfig</code></a> via parameter |
| <a href="../StreamsConfig.html#APPLICATION_ID_CONFIG"><code>APPLICATION_ID_CONFIG</code></a>, "<name>" is an internally generated |
| name, and "-repartition" is a fixed suffix. |
| <p> |
| Repartitioning can happen for one or both of the joining <code>KStream</code>s. |
| For this case, all data of the stream will be redistributed through the repartitioning topic by writing all |
| records to it, and rereading all records from it, such that the join input <code>KStream</code> is partitioned |
| correctly on its key. |
| <p> |
| Both of the joining <code>KStream</code>s will be materialized in local state stores with auto-generated store names, |
| unless a name is provided via a <code>Materialized</code> instance. |
| For failure and recovery each store will be backed by an internal changelog topic that will be created in Kafka. |
| The changelog topic will be named "${applicationId}-<storename>-changelog", where "applicationId" is user-specified |
| in <a href="../StreamsConfig.html" title="class in org.apache.kafka.streams"><code>StreamsConfig</code></a> via parameter |
| <a href="../StreamsConfig.html#APPLICATION_ID_CONFIG"><code>APPLICATION_ID_CONFIG</code></a>, "storeName" is an |
| internally generated name, and "-changelog" is a fixed suffix. |
| <p> |
| You can retrieve all generated internal topic names via <a href="../Topology.html#describe()"><code>Topology.describe()</code></a>.</div> |
| <dl class="notes"> |
| <dt>Type Parameters:</dt> |
| <dd><code>VO</code> - the value type of the other stream</dd> |
| <dd><code>VR</code> - the value type of the result stream</dd> |
| <dt>Parameters:</dt> |
| <dd><code>otherStream</code> - the <code>KStream</code> to be joined with this stream</dd> |
| <dd><code>joiner</code> - a <a href="ValueJoiner.html" title="interface in org.apache.kafka.streams.kstream"><code>ValueJoiner</code></a> that computes the join result for a pair of matching records</dd> |
| <dd><code>windows</code> - the specification of the <a href="JoinWindows.html" title="class in org.apache.kafka.streams.kstream"><code>JoinWindows</code></a></dd> |
| <dd><code>streamJoined</code> - a <a href="StreamJoined.html" title="class in org.apache.kafka.streams.kstream"><code>StreamJoined</code></a> used to configure join stores</dd> |
| <dt>Returns:</dt> |
| <dd>a <code>KStream</code> that contains join-records for each key and values computed by the given |
| <a href="ValueJoiner.html" title="interface in org.apache.kafka.streams.kstream"><code>ValueJoiner</code></a>, one for each matched record-pair with the same key and within the joining window intervals</dd> |
| <dt>See Also:</dt> |
| <dd> |
| <ul class="see-list-long"> |
| <li><a href="#leftJoin(org.apache.kafka.streams.kstream.KStream,org.apache.kafka.streams.kstream.ValueJoiner,org.apache.kafka.streams.kstream.JoinWindows,org.apache.kafka.streams.kstream.StreamJoined)"><code>leftJoin(KStream, ValueJoiner, JoinWindows, StreamJoined)</code></a></li> |
| <li><a href="#outerJoin(org.apache.kafka.streams.kstream.KStream,org.apache.kafka.streams.kstream.ValueJoiner,org.apache.kafka.streams.kstream.JoinWindows,org.apache.kafka.streams.kstream.StreamJoined)"><code>outerJoin(KStream, ValueJoiner, JoinWindows, StreamJoined)</code></a></li> |
| </ul> |
| </dd> |
| </dl> |
| </section> |
| </li> |
| <li> |
| <section class="detail" id="join(org.apache.kafka.streams.kstream.KStream,org.apache.kafka.streams.kstream.ValueJoinerWithKey,org.apache.kafka.streams.kstream.JoinWindows,org.apache.kafka.streams.kstream.StreamJoined)"> |
| <h3>join</h3> |
| <div class="member-signature"><span class="type-parameters"><VO,<wbr> |
| VR></span> <span class="return-type"><a href="KStream.html" title="interface in org.apache.kafka.streams.kstream">KStream</a><<a href="KStream.html" title="type parameter in KStream">K</a>,<wbr>VR></span> <span class="element-name">join</span><wbr><span class="parameters">(<a href="KStream.html" title="interface in org.apache.kafka.streams.kstream">KStream</a><<a href="KStream.html" title="type parameter in KStream">K</a>,<wbr>VO> otherStream, |
| <a href="ValueJoinerWithKey.html" title="interface in org.apache.kafka.streams.kstream">ValueJoinerWithKey</a><? super <a href="KStream.html" title="type parameter in KStream">K</a>,<wbr>? super <a href="KStream.html" title="type parameter in KStream">V</a>,<wbr>? super VO,<wbr>? extends VR> joiner, |
| <a href="JoinWindows.html" title="class in org.apache.kafka.streams.kstream">JoinWindows</a> windows, |
| <a href="StreamJoined.html" title="class in org.apache.kafka.streams.kstream">StreamJoined</a><<a href="KStream.html" title="type parameter in KStream">K</a>,<wbr><a href="KStream.html" title="type parameter in KStream">V</a>,<wbr>VO> streamJoined)</span></div> |
| <div class="block">Join records of this stream with another <code>KStream</code>'s records using windowed inner equi join using the |
| <a href="StreamJoined.html" title="class in org.apache.kafka.streams.kstream"><code>StreamJoined</code></a> instance for configuration of the <a href="../../common/serialization/Serde.html" title="interface in org.apache.kafka.common.serialization"><code>key serde</code></a>, <a href="../../common/serialization/Serde.html" title="interface in org.apache.kafka.common.serialization"><code>this stream's value |
| serde</code></a>, <a href="../../common/serialization/Serde.html" title="interface in org.apache.kafka.common.serialization"><code>the other stream's value serde</code></a>, and used state stores. |
| The join is computed on the records' key with join attribute <code>thisKStream.key == otherKStream.key</code>. |
| Furthermore, two records are only joined if their timestamps are close to each other as defined by the given |
| <a href="JoinWindows.html" title="class in org.apache.kafka.streams.kstream"><code>JoinWindows</code></a>, i.e., the window defines an additional join predicate on the record timestamps. |
| <p> |
| For each pair of records meeting both join predicates the provided <a href="ValueJoinerWithKey.html" title="interface in org.apache.kafka.streams.kstream"><code>ValueJoinerWithKey</code></a> will be called to compute |
| a value (with arbitrary type) for the result record. |
| Note that the key is read-only and should not be modified, as this can lead to undefined behaviour. |
| The key of the result record is the same as for both joining input records. |
| If an input record key or value is <code>null</code> the record will not be included in the join operation and thus no |
| output record will be added to the resulting <code>KStream</code>. |
| <p> |
| Example (assuming all input records belong to the correct windows): |
| <table border='1'> |
| <tr> |
| <th>this</th> |
| <th>other</th> |
| <th>result</th> |
| </tr> |
| <tr> |
| <td><K1:A></td> |
| <td></td> |
| <td></td> |
| </tr> |
| <tr> |
| <td><K2:B></td> |
| <td><K2:b></td> |
| <td><K2:ValueJoinerWithKey(K1,B,b)></td> |
| </tr> |
| <tr> |
| <td></td> |
| <td><K3:c></td> |
| <td></td> |
| </tr> |
| </table> |
| Both input streams (or to be more precise, their underlying source topics) need to have the same number of |
| partitions. |
| If this is not the case, you would need to call <a href="#repartition(org.apache.kafka.streams.kstream.Repartitioned)"><code>repartition(Repartitioned)</code></a> (for one input stream) before |
| doing the join and specify the "correct" number of partitions via <a href="Repartitioned.html" title="class in org.apache.kafka.streams.kstream"><code>Repartitioned</code></a> parameter. |
| Furthermore, both input streams need to be co-partitioned on the join key (i.e., use the same partitioner). |
| If this requirement is not met, Kafka Streams will automatically repartition the data, i.e., it will create an |
| internal repartitioning topic in Kafka and write and re-read the data via this topic before the actual join. |
| The repartitioning topic will be named "${applicationId}-<name>-repartition", where "applicationId" is |
| user-specified in <a href="../StreamsConfig.html" title="class in org.apache.kafka.streams"><code>StreamsConfig</code></a> via parameter |
| <a href="../StreamsConfig.html#APPLICATION_ID_CONFIG"><code>APPLICATION_ID_CONFIG</code></a>, "<name>" is an internally generated |
| name, and "-repartition" is a fixed suffix. |
| <p> |
| Repartitioning can happen for one or both of the joining <code>KStream</code>s. |
| For this case, all data of the stream will be redistributed through the repartitioning topic by writing all |
| records to it, and rereading all records from it, such that the join input <code>KStream</code> is partitioned |
| correctly on its key. |
| <p> |
| Both of the joining <code>KStream</code>s will be materialized in local state stores with auto-generated store names, |
| unless a name is provided via a <code>Materialized</code> instance. |
| For failure and recovery each store will be backed by an internal changelog topic that will be created in Kafka. |
| The changelog topic will be named "${applicationId}-<storename>-changelog", where "applicationId" is user-specified |
| in <a href="../StreamsConfig.html" title="class in org.apache.kafka.streams"><code>StreamsConfig</code></a> via parameter |
| <a href="../StreamsConfig.html#APPLICATION_ID_CONFIG"><code>APPLICATION_ID_CONFIG</code></a>, "storeName" is an |
| internally generated name, and "-changelog" is a fixed suffix. |
| <p> |
| You can retrieve all generated internal topic names via <a href="../Topology.html#describe()"><code>Topology.describe()</code></a>.</div> |
| <dl class="notes"> |
| <dt>Type Parameters:</dt> |
| <dd><code>VO</code> - the value type of the other stream</dd> |
| <dd><code>VR</code> - the value type of the result stream</dd> |
| <dt>Parameters:</dt> |
| <dd><code>otherStream</code> - the <code>KStream</code> to be joined with this stream</dd> |
| <dd><code>joiner</code> - a <a href="ValueJoinerWithKey.html" title="interface in org.apache.kafka.streams.kstream"><code>ValueJoinerWithKey</code></a> that computes the join result for a pair of matching records</dd> |
| <dd><code>windows</code> - the specification of the <a href="JoinWindows.html" title="class in org.apache.kafka.streams.kstream"><code>JoinWindows</code></a></dd> |
| <dd><code>streamJoined</code> - a <a href="StreamJoined.html" title="class in org.apache.kafka.streams.kstream"><code>StreamJoined</code></a> used to configure join stores</dd> |
| <dt>Returns:</dt> |
| <dd>a <code>KStream</code> that contains join-records for each key and values computed by the given |
| <a href="ValueJoinerWithKey.html" title="interface in org.apache.kafka.streams.kstream"><code>ValueJoinerWithKey</code></a>, one for each matched record-pair with the same key and within the joining window intervals</dd> |
| <dt>See Also:</dt> |
| <dd> |
| <ul class="see-list-long"> |
| <li><a href="#leftJoin(org.apache.kafka.streams.kstream.KStream,org.apache.kafka.streams.kstream.ValueJoinerWithKey,org.apache.kafka.streams.kstream.JoinWindows,org.apache.kafka.streams.kstream.StreamJoined)"><code>leftJoin(KStream, ValueJoinerWithKey, JoinWindows, StreamJoined)</code></a></li> |
| <li><a href="#outerJoin(org.apache.kafka.streams.kstream.KStream,org.apache.kafka.streams.kstream.ValueJoinerWithKey,org.apache.kafka.streams.kstream.JoinWindows,org.apache.kafka.streams.kstream.StreamJoined)"><code>outerJoin(KStream, ValueJoinerWithKey, JoinWindows, StreamJoined)</code></a></li> |
| </ul> |
| </dd> |
| </dl> |
| </section> |
| </li> |
| <li> |
| <section class="detail" id="leftJoin(org.apache.kafka.streams.kstream.KStream,org.apache.kafka.streams.kstream.ValueJoiner,org.apache.kafka.streams.kstream.JoinWindows)"> |
| <h3>leftJoin</h3> |
| <div class="member-signature"><span class="type-parameters"><VO,<wbr> |
| VR></span> <span class="return-type"><a href="KStream.html" title="interface in org.apache.kafka.streams.kstream">KStream</a><<a href="KStream.html" title="type parameter in KStream">K</a>,<wbr>VR></span> <span class="element-name">leftJoin</span><wbr><span class="parameters">(<a href="KStream.html" title="interface in org.apache.kafka.streams.kstream">KStream</a><<a href="KStream.html" title="type parameter in KStream">K</a>,<wbr>VO> otherStream, |
| <a href="ValueJoiner.html" title="interface in org.apache.kafka.streams.kstream">ValueJoiner</a><? super <a href="KStream.html" title="type parameter in KStream">V</a>,<wbr>? super VO,<wbr>? extends VR> joiner, |
| <a href="JoinWindows.html" title="class in org.apache.kafka.streams.kstream">JoinWindows</a> windows)</span></div> |
| <div class="block">Join records of this stream with another <code>KStream</code>'s records using windowed left equi join with default |
| serializers and deserializers. |
| In contrast to <a href="#join(org.apache.kafka.streams.kstream.KStream,org.apache.kafka.streams.kstream.ValueJoiner,org.apache.kafka.streams.kstream.JoinWindows)"><code>inner-join</code></a>, all records from this stream will |
| produce at least one output record (cf. below). |
| The join is computed on the records' key with join attribute <code>thisKStream.key == otherKStream.key</code>. |
| Furthermore, two records are only joined if their timestamps are close to each other as defined by the given |
| <a href="JoinWindows.html" title="class in org.apache.kafka.streams.kstream"><code>JoinWindows</code></a>, i.e., the window defines an additional join predicate on the record timestamps. |
| <p> |
| For each pair of records meeting both join predicates the provided <a href="ValueJoiner.html" title="interface in org.apache.kafka.streams.kstream"><code>ValueJoiner</code></a> will be called to compute |
| a value (with arbitrary type) for the result record. |
| The key of the result record is the same as for both joining input records. |
| Furthermore, for each input record of this <code>KStream</code> that does not satisfy the join predicate the provided |
| <a href="ValueJoiner.html" title="interface in org.apache.kafka.streams.kstream"><code>ValueJoiner</code></a> will be called with a <code>null</code> value for the other stream. |
| If an input record key or value is <code>null</code> the record will not be included in the join operation and thus no |
| output record will be added to the resulting <code>KStream</code>. |
| <p> |
| Example (assuming all input records belong to the correct windows): |
| <table border='1'> |
| <tr> |
| <th>this</th> |
| <th>other</th> |
| <th>result</th> |
| </tr> |
| <tr> |
| <td><K1:A></td> |
| <td></td> |
| <td><K1:ValueJoiner(A,null)></td> |
| </tr> |
| <tr> |
| <td><K2:B></td> |
| <td><K2:b></td> |
| <td><K2:ValueJoiner(B,b)></td> |
| </tr> |
| <tr> |
| <td></td> |
| <td><K3:c></td> |
| <td></td> |
| </tr> |
| </table> |
| Both input streams (or to be more precise, their underlying source topics) need to have the same number of |
| partitions. |
| If this is not the case, you would need to call <a href="#repartition(org.apache.kafka.streams.kstream.Repartitioned)"><code>repartition(Repartitioned)</code></a> (for one input stream) before |
| doing the join and specify the "correct" number of partitions via <a href="Repartitioned.html" title="class in org.apache.kafka.streams.kstream"><code>Repartitioned</code></a> parameter. |
| Furthermore, both input streams need to be co-partitioned on the join key (i.e., use the same partitioner). |
| If this requirement is not met, Kafka Streams will automatically repartition the data, i.e., it will create an |
| internal repartitioning topic in Kafka and write and re-read the data via this topic before the actual join. |
| The repartitioning topic will be named "${applicationId}-<name>-repartition", where "applicationId" is |
| user-specified in <a href="../StreamsConfig.html" title="class in org.apache.kafka.streams"><code>StreamsConfig</code></a> via parameter |
| <a href="../StreamsConfig.html#APPLICATION_ID_CONFIG"><code>APPLICATION_ID_CONFIG</code></a>, "<name>" is an internally generated |
| name, and "-repartition" is a fixed suffix. |
| <p> |
| Repartitioning can happen for one or both of the joining <code>KStream</code>s. |
| For this case, all data of the stream will be redistributed through the repartitioning topic by writing all |
| records to it, and rereading all records from it, such that the join input <code>KStream</code> is partitioned |
| correctly on its key. |
| <p> |
| Both of the joining <code>KStream</code>s will be materialized in local state stores with auto-generated store names. |
| For failure and recovery each store will be backed by an internal changelog topic that will be created in Kafka. |
| The changelog topic will be named "${applicationId}-<storename>-changelog", where "applicationId" is user-specified |
| in <a href="../StreamsConfig.html" title="class in org.apache.kafka.streams"><code>StreamsConfig</code></a> via parameter <a href="../StreamsConfig.html#APPLICATION_ID_CONFIG"><code>APPLICATION_ID_CONFIG</code></a>, |
| "storeName" is an internally generated name, and "-changelog" is a fixed suffix. |
| <p> |
| You can retrieve all generated internal topic names via <a href="../Topology.html#describe()"><code>Topology.describe()</code></a>.</div> |
| <dl class="notes"> |
| <dt>Type Parameters:</dt> |
| <dd><code>VO</code> - the value type of the other stream</dd> |
| <dd><code>VR</code> - the value type of the result stream</dd> |
| <dt>Parameters:</dt> |
| <dd><code>otherStream</code> - the <code>KStream</code> to be joined with this stream</dd> |
| <dd><code>joiner</code> - a <a href="ValueJoiner.html" title="interface in org.apache.kafka.streams.kstream"><code>ValueJoiner</code></a> that computes the join result for a pair of matching records</dd> |
| <dd><code>windows</code> - the specification of the <a href="JoinWindows.html" title="class in org.apache.kafka.streams.kstream"><code>JoinWindows</code></a></dd> |
| <dt>Returns:</dt> |
| <dd>a <code>KStream</code> that contains join-records for each key and values computed by the given |
| <a href="ValueJoiner.html" title="interface in org.apache.kafka.streams.kstream"><code>ValueJoiner</code></a>, one for each matched record-pair with the same key plus one for each non-matching record of |
| this <code>KStream</code> and within the joining window intervals</dd> |
| <dt>See Also:</dt> |
| <dd> |
| <ul class="see-list-long"> |
| <li><a href="#join(org.apache.kafka.streams.kstream.KStream,org.apache.kafka.streams.kstream.ValueJoiner,org.apache.kafka.streams.kstream.JoinWindows)"><code>join(KStream, ValueJoiner, JoinWindows)</code></a></li> |
| <li><a href="#outerJoin(org.apache.kafka.streams.kstream.KStream,org.apache.kafka.streams.kstream.ValueJoiner,org.apache.kafka.streams.kstream.JoinWindows)"><code>outerJoin(KStream, ValueJoiner, JoinWindows)</code></a></li> |
| </ul> |
| </dd> |
| </dl> |
| </section> |
| </li> |
| <li> |
| <section class="detail" id="leftJoin(org.apache.kafka.streams.kstream.KStream,org.apache.kafka.streams.kstream.ValueJoinerWithKey,org.apache.kafka.streams.kstream.JoinWindows)"> |
| <h3>leftJoin</h3> |
| <div class="member-signature"><span class="type-parameters"><VO,<wbr> |
| VR></span> <span class="return-type"><a href="KStream.html" title="interface in org.apache.kafka.streams.kstream">KStream</a><<a href="KStream.html" title="type parameter in KStream">K</a>,<wbr>VR></span> <span class="element-name">leftJoin</span><wbr><span class="parameters">(<a href="KStream.html" title="interface in org.apache.kafka.streams.kstream">KStream</a><<a href="KStream.html" title="type parameter in KStream">K</a>,<wbr>VO> otherStream, |
| <a href="ValueJoinerWithKey.html" title="interface in org.apache.kafka.streams.kstream">ValueJoinerWithKey</a><? super <a href="KStream.html" title="type parameter in KStream">K</a>,<wbr>? super <a href="KStream.html" title="type parameter in KStream">V</a>,<wbr>? super VO,<wbr>? extends VR> joiner, |
| <a href="JoinWindows.html" title="class in org.apache.kafka.streams.kstream">JoinWindows</a> windows)</span></div> |
| <div class="block">Join records of this stream with another <code>KStream</code>'s records using windowed left equi join with default |
| serializers and deserializers. |
| In contrast to <a href="#join(org.apache.kafka.streams.kstream.KStream,org.apache.kafka.streams.kstream.ValueJoinerWithKey,org.apache.kafka.streams.kstream.JoinWindows)"><code>inner-join</code></a>, all records from this stream will |
| produce at least one output record (cf. below). |
| The join is computed on the records' key with join attribute <code>thisKStream.key == otherKStream.key</code>. |
| Furthermore, two records are only joined if their timestamps are close to each other as defined by the given |
| <a href="JoinWindows.html" title="class in org.apache.kafka.streams.kstream"><code>JoinWindows</code></a>, i.e., the window defines an additional join predicate on the record timestamps. |
| <p> |
| For each pair of records meeting both join predicates the provided <a href="ValueJoinerWithKey.html" title="interface in org.apache.kafka.streams.kstream"><code>ValueJoinerWithKey</code></a> will be called to compute |
| a value (with arbitrary type) for the result record. |
| Note that the key is read-only and should not be modified, as this can lead to undefined behaviour. |
| The key of the result record is the same as for both joining input records. |
| Furthermore, for each input record of this <code>KStream</code> that does not satisfy the join predicate the provided |
| <a href="ValueJoinerWithKey.html" title="interface in org.apache.kafka.streams.kstream"><code>ValueJoinerWithKey</code></a> will be called with a <code>null</code> value for the other stream. |
| If an input record key or value is <code>null</code> the record will not be included in the join operation and thus no |
| output record will be added to the resulting <code>KStream</code>. |
| <p> |
| Example (assuming all input records belong to the correct windows): |
| <table border='1'> |
| <tr> |
| <th>this</th> |
| <th>other</th> |
| <th>result</th> |
| </tr> |
| <tr> |
| <td><K1:A></td> |
| <td></td> |
| <td><K1:ValueJoinerWithKey(K1, A,null)></td> |
| </tr> |
| <tr> |
| <td><K2:B></td> |
| <td><K2:b></td> |
| <td><K2:ValueJoinerWithKey(K2, B,b)></td> |
| </tr> |
| <tr> |
| <td></td> |
| <td><K3:c></td> |
| <td></td> |
| </tr> |
| </table> |
| Both input streams (or to be more precise, their underlying source topics) need to have the same number of |
| partitions. |
| If this is not the case, you would need to call <a href="#repartition(org.apache.kafka.streams.kstream.Repartitioned)"><code>repartition(Repartitioned)</code></a> (for one input stream) before |
| doing the join and specify the "correct" number of partitions via <a href="Repartitioned.html" title="class in org.apache.kafka.streams.kstream"><code>Repartitioned</code></a> parameter. |
| Furthermore, both input streams need to be co-partitioned on the join key (i.e., use the same partitioner). |
| If this requirement is not met, Kafka Streams will automatically repartition the data, i.e., it will create an |
| internal repartitioning topic in Kafka and write and re-read the data via this topic before the actual join. |
| The repartitioning topic will be named "${applicationId}-<name>-repartition", where "applicationId" is |
| user-specified in <a href="../StreamsConfig.html" title="class in org.apache.kafka.streams"><code>StreamsConfig</code></a> via parameter |
| <a href="../StreamsConfig.html#APPLICATION_ID_CONFIG"><code>APPLICATION_ID_CONFIG</code></a>, "<name>" is an internally generated |
| name, and "-repartition" is a fixed suffix. |
| <p> |
| Repartitioning can happen for one or both of the joining <code>KStream</code>s. |
| For this case, all data of the stream will be redistributed through the repartitioning topic by writing all |
| records to it, and rereading all records from it, such that the join input <code>KStream</code> is partitioned |
| correctly on its key. |
| <p> |
| Both of the joining <code>KStream</code>s will be materialized in local state stores with auto-generated store names. |
| For failure and recovery each store will be backed by an internal changelog topic that will be created in Kafka. |
| The changelog topic will be named "${applicationId}-<storename>-changelog", where "applicationId" is user-specified |
| in <a href="../StreamsConfig.html" title="class in org.apache.kafka.streams"><code>StreamsConfig</code></a> via parameter <a href="../StreamsConfig.html#APPLICATION_ID_CONFIG"><code>APPLICATION_ID_CONFIG</code></a>, |
| "storeName" is an internally generated name, and "-changelog" is a fixed suffix. |
| <p> |
| You can retrieve all generated internal topic names via <a href="../Topology.html#describe()"><code>Topology.describe()</code></a>.</div> |
| <dl class="notes"> |
| <dt>Type Parameters:</dt> |
| <dd><code>VO</code> - the value type of the other stream</dd> |
| <dd><code>VR</code> - the value type of the result stream</dd> |
| <dt>Parameters:</dt> |
| <dd><code>otherStream</code> - the <code>KStream</code> to be joined with this stream</dd> |
| <dd><code>joiner</code> - a <a href="ValueJoinerWithKey.html" title="interface in org.apache.kafka.streams.kstream"><code>ValueJoinerWithKey</code></a> that computes the join result for a pair of matching records</dd> |
| <dd><code>windows</code> - the specification of the <a href="JoinWindows.html" title="class in org.apache.kafka.streams.kstream"><code>JoinWindows</code></a></dd> |
| <dt>Returns:</dt> |
| <dd>a <code>KStream</code> that contains join-records for each key and values computed by the given |
| <a href="ValueJoinerWithKey.html" title="interface in org.apache.kafka.streams.kstream"><code>ValueJoinerWithKey</code></a>, one for each matched record-pair with the same key plus one for each non-matching record of |
| this <code>KStream</code> and within the joining window intervals</dd> |
| <dt>See Also:</dt> |
| <dd> |
| <ul class="see-list-long"> |
| <li><a href="#join(org.apache.kafka.streams.kstream.KStream,org.apache.kafka.streams.kstream.ValueJoinerWithKey,org.apache.kafka.streams.kstream.JoinWindows)"><code>join(KStream, ValueJoinerWithKey, JoinWindows)</code></a></li> |
| <li><a href="#outerJoin(org.apache.kafka.streams.kstream.KStream,org.apache.kafka.streams.kstream.ValueJoinerWithKey,org.apache.kafka.streams.kstream.JoinWindows)"><code>outerJoin(KStream, ValueJoinerWithKey, JoinWindows)</code></a></li> |
| </ul> |
| </dd> |
| </dl> |
| </section> |
| </li> |
| <li> |
| <section class="detail" id="leftJoin(org.apache.kafka.streams.kstream.KStream,org.apache.kafka.streams.kstream.ValueJoiner,org.apache.kafka.streams.kstream.JoinWindows,org.apache.kafka.streams.kstream.StreamJoined)"> |
| <h3>leftJoin</h3> |
| <div class="member-signature"><span class="type-parameters"><VO,<wbr> |
| VR></span> <span class="return-type"><a href="KStream.html" title="interface in org.apache.kafka.streams.kstream">KStream</a><<a href="KStream.html" title="type parameter in KStream">K</a>,<wbr>VR></span> <span class="element-name">leftJoin</span><wbr><span class="parameters">(<a href="KStream.html" title="interface in org.apache.kafka.streams.kstream">KStream</a><<a href="KStream.html" title="type parameter in KStream">K</a>,<wbr>VO> otherStream, |
| <a href="ValueJoiner.html" title="interface in org.apache.kafka.streams.kstream">ValueJoiner</a><? super <a href="KStream.html" title="type parameter in KStream">V</a>,<wbr>? super VO,<wbr>? extends VR> joiner, |
| <a href="JoinWindows.html" title="class in org.apache.kafka.streams.kstream">JoinWindows</a> windows, |
| <a href="StreamJoined.html" title="class in org.apache.kafka.streams.kstream">StreamJoined</a><<a href="KStream.html" title="type parameter in KStream">K</a>,<wbr><a href="KStream.html" title="type parameter in KStream">V</a>,<wbr>VO> streamJoined)</span></div> |
| <div class="block">Join records of this stream with another <code>KStream</code>'s records using windowed left equi join using the |
| <a href="StreamJoined.html" title="class in org.apache.kafka.streams.kstream"><code>StreamJoined</code></a> instance for configuration of the <a href="../../common/serialization/Serde.html" title="interface in org.apache.kafka.common.serialization"><code>key serde</code></a>, <a href="../../common/serialization/Serde.html" title="interface in org.apache.kafka.common.serialization"><code>this stream's value |
| serde</code></a>, <a href="../../common/serialization/Serde.html" title="interface in org.apache.kafka.common.serialization"><code>the other stream's value serde</code></a>, and used state stores. |
| In contrast to <a href="#join(org.apache.kafka.streams.kstream.KStream,org.apache.kafka.streams.kstream.ValueJoiner,org.apache.kafka.streams.kstream.JoinWindows)"><code>inner-join</code></a>, all records from this stream will |
| produce at least one output record (cf. below). |
| The join is computed on the records' key with join attribute <code>thisKStream.key == otherKStream.key</code>. |
| Furthermore, two records are only joined if their timestamps are close to each other as defined by the given |
| <a href="JoinWindows.html" title="class in org.apache.kafka.streams.kstream"><code>JoinWindows</code></a>, i.e., the window defines an additional join predicate on the record timestamps. |
| <p> |
| For each pair of records meeting both join predicates the provided <a href="ValueJoiner.html" title="interface in org.apache.kafka.streams.kstream"><code>ValueJoiner</code></a> will be called to compute |
| a value (with arbitrary type) for the result record. |
| The key of the result record is the same as for both joining input records. |
| Furthermore, for each input record of this <code>KStream</code> that does not satisfy the join predicate the provided |
| <a href="ValueJoiner.html" title="interface in org.apache.kafka.streams.kstream"><code>ValueJoiner</code></a> will be called with a <code>null</code> value for the other stream. |
| If an input record key or value is <code>null</code> the record will not be included in the join operation and thus no |
| output record will be added to the resulting <code>KStream</code>. |
| <p> |
| Example (assuming all input records belong to the correct windows): |
| <table border='1'> |
| <tr> |
| <th>this</th> |
| <th>other</th> |
| <th>result</th> |
| </tr> |
| <tr> |
| <td><K1:A></td> |
| <td></td> |
| <td><K1:ValueJoiner(A,null)></td> |
| </tr> |
| <tr> |
| <td><K2:B></td> |
| <td><K2:b></td> |
| <td><K2:ValueJoiner(B,b)></td> |
| </tr> |
| <tr> |
| <td></td> |
| <td><K3:c></td> |
| <td></td> |
| </tr> |
| </table> |
| Both input streams (or to be more precise, their underlying source topics) need to have the same number of |
| partitions. |
| If this is not the case, you would need to call <a href="#repartition(org.apache.kafka.streams.kstream.Repartitioned)"><code>repartition(Repartitioned)</code></a> (for one input stream) before |
| doing the join and specify the "correct" number of partitions via <a href="Repartitioned.html" title="class in org.apache.kafka.streams.kstream"><code>Repartitioned</code></a> parameter. |
| Furthermore, both input streams need to be co-partitioned on the join key (i.e., use the same partitioner). |
| If this requirement is not met, Kafka Streams will automatically repartition the data, i.e., it will create an |
| internal repartitioning topic in Kafka and write and re-read the data via this topic before the actual join. |
| The repartitioning topic will be named "${applicationId}-<name>-repartition", where "applicationId" is |
| user-specified in <a href="../StreamsConfig.html" title="class in org.apache.kafka.streams"><code>StreamsConfig</code></a> via parameter |
| <a href="../StreamsConfig.html#APPLICATION_ID_CONFIG"><code>APPLICATION_ID_CONFIG</code></a>, "<name>" is an internally generated |
| name, and "-repartition" is a fixed suffix. |
| <p> |
| Repartitioning can happen for one or both of the joining <code>KStream</code>s. |
| For this case, all data of the stream will be redistributed through the repartitioning topic by writing all |
| records to it, and rereading all records from it, such that the join input <code>KStream</code> is partitioned |
| correctly on its key. |
| <p> |
| Both of the joining <code>KStream</code>s will be materialized in local state stores with auto-generated store names, |
| unless a name is provided via a <code>Materialized</code> instance. |
| For failure and recovery each store will be backed by an internal changelog topic that will be created in Kafka. |
| The changelog topic will be named "${applicationId}-<storename>-changelog", where "applicationId" is user-specified |
| in <a href="../StreamsConfig.html" title="class in org.apache.kafka.streams"><code>StreamsConfig</code></a> via parameter <a href="../StreamsConfig.html#APPLICATION_ID_CONFIG"><code>APPLICATION_ID_CONFIG</code></a>, |
| "storeName" is an internally generated name, and "-changelog" is a fixed suffix. |
| <p> |
| You can retrieve all generated internal topic names via <a href="../Topology.html#describe()"><code>Topology.describe()</code></a>.</div> |
| <dl class="notes"> |
| <dt>Type Parameters:</dt> |
| <dd><code>VO</code> - the value type of the other stream</dd> |
| <dd><code>VR</code> - the value type of the result stream</dd> |
| <dt>Parameters:</dt> |
| <dd><code>otherStream</code> - the <code>KStream</code> to be joined with this stream</dd> |
| <dd><code>joiner</code> - a <a href="ValueJoiner.html" title="interface in org.apache.kafka.streams.kstream"><code>ValueJoiner</code></a> that computes the join result for a pair of matching records</dd> |
| <dd><code>windows</code> - the specification of the <a href="JoinWindows.html" title="class in org.apache.kafka.streams.kstream"><code>JoinWindows</code></a></dd> |
| <dd><code>streamJoined</code> - a <a href="StreamJoined.html" title="class in org.apache.kafka.streams.kstream"><code>StreamJoined</code></a> instance to configure serdes and state stores</dd> |
| <dt>Returns:</dt> |
| <dd>a <code>KStream</code> that contains join-records for each key and values computed by the given |
| <a href="ValueJoiner.html" title="interface in org.apache.kafka.streams.kstream"><code>ValueJoiner</code></a>, one for each matched record-pair with the same key plus one for each non-matching record of |
| this <code>KStream</code> and within the joining window intervals</dd> |
| <dt>See Also:</dt> |
| <dd> |
| <ul class="see-list-long"> |
| <li><a href="#join(org.apache.kafka.streams.kstream.KStream,org.apache.kafka.streams.kstream.ValueJoiner,org.apache.kafka.streams.kstream.JoinWindows,org.apache.kafka.streams.kstream.StreamJoined)"><code>join(KStream, ValueJoiner, JoinWindows, StreamJoined)</code></a></li> |
| <li><a href="#outerJoin(org.apache.kafka.streams.kstream.KStream,org.apache.kafka.streams.kstream.ValueJoiner,org.apache.kafka.streams.kstream.JoinWindows,org.apache.kafka.streams.kstream.StreamJoined)"><code>outerJoin(KStream, ValueJoiner, JoinWindows, StreamJoined)</code></a></li> |
| </ul> |
| </dd> |
| </dl> |
| </section> |
| </li> |
| <li> |
| <section class="detail" id="leftJoin(org.apache.kafka.streams.kstream.KStream,org.apache.kafka.streams.kstream.ValueJoinerWithKey,org.apache.kafka.streams.kstream.JoinWindows,org.apache.kafka.streams.kstream.StreamJoined)"> |
| <h3>leftJoin</h3> |
| <div class="member-signature"><span class="type-parameters"><VO,<wbr> |
| VR></span> <span class="return-type"><a href="KStream.html" title="interface in org.apache.kafka.streams.kstream">KStream</a><<a href="KStream.html" title="type parameter in KStream">K</a>,<wbr>VR></span> <span class="element-name">leftJoin</span><wbr><span class="parameters">(<a href="KStream.html" title="interface in org.apache.kafka.streams.kstream">KStream</a><<a href="KStream.html" title="type parameter in KStream">K</a>,<wbr>VO> otherStream, |
| <a href="ValueJoinerWithKey.html" title="interface in org.apache.kafka.streams.kstream">ValueJoinerWithKey</a><? super <a href="KStream.html" title="type parameter in KStream">K</a>,<wbr>? super <a href="KStream.html" title="type parameter in KStream">V</a>,<wbr>? super VO,<wbr>? extends VR> joiner, |
| <a href="JoinWindows.html" title="class in org.apache.kafka.streams.kstream">JoinWindows</a> windows, |
| <a href="StreamJoined.html" title="class in org.apache.kafka.streams.kstream">StreamJoined</a><<a href="KStream.html" title="type parameter in KStream">K</a>,<wbr><a href="KStream.html" title="type parameter in KStream">V</a>,<wbr>VO> streamJoined)</span></div> |
| <div class="block">Join records of this stream with another <code>KStream</code>'s records using windowed left equi join using the |
| <a href="StreamJoined.html" title="class in org.apache.kafka.streams.kstream"><code>StreamJoined</code></a> instance for configuration of the <a href="../../common/serialization/Serde.html" title="interface in org.apache.kafka.common.serialization"><code>key serde</code></a>, <a href="../../common/serialization/Serde.html" title="interface in org.apache.kafka.common.serialization"><code>this stream's value |
| serde</code></a>, <a href="../../common/serialization/Serde.html" title="interface in org.apache.kafka.common.serialization"><code>the other stream's value serde</code></a>, and used state stores. |
| In contrast to <a href="#join(org.apache.kafka.streams.kstream.KStream,org.apache.kafka.streams.kstream.ValueJoinerWithKey,org.apache.kafka.streams.kstream.JoinWindows)"><code>inner-join</code></a>, all records from this stream will |
| produce at least one output record (cf. below). |
| The join is computed on the records' key with join attribute <code>thisKStream.key == otherKStream.key</code>. |
| Furthermore, two records are only joined if their timestamps are close to each other as defined by the given |
| <a href="JoinWindows.html" title="class in org.apache.kafka.streams.kstream"><code>JoinWindows</code></a>, i.e., the window defines an additional join predicate on the record timestamps. |
| <p> |
| For each pair of records meeting both join predicates the provided <a href="ValueJoinerWithKey.html" title="interface in org.apache.kafka.streams.kstream"><code>ValueJoinerWithKey</code></a> will be called to compute |
| a value (with arbitrary type) for the result record. |
| Note that the key is read-only and should not be modified, as this can lead to undefined behaviour. |
| The key of the result record is the same as for both joining input records. |
| Furthermore, for each input record of this <code>KStream</code> that does not satisfy the join predicate the provided |
| <a href="ValueJoinerWithKey.html" title="interface in org.apache.kafka.streams.kstream"><code>ValueJoinerWithKey</code></a> will be called with a <code>null</code> value for the other stream. |
| If an input record key or value is <code>null</code> the record will not be included in the join operation and thus no |
| output record will be added to the resulting <code>KStream</code>. |
| <p> |
| Example (assuming all input records belong to the correct windows): |
| <table border='1'> |
| <tr> |
| <th>this</th> |
| <th>other</th> |
| <th>result</th> |
| </tr> |
| <tr> |
| <td><K1:A></td> |
| <td></td> |
| <td><K1:ValueJoinerWithKey(K1,A,null)></td> |
| </tr> |
| <tr> |
| <td><K2:B></td> |
| <td><K2:b></td> |
| <td><K2:ValueJoinerWithKey(K2,B,b)></td> |
| </tr> |
| <tr> |
| <td></td> |
| <td><K3:c></td> |
| <td></td> |
| </tr> |
| </table> |
| Both input streams (or to be more precise, their underlying source topics) need to have the same number of |
| partitions. |
| If this is not the case, you would need to call <a href="#repartition(org.apache.kafka.streams.kstream.Repartitioned)"><code>repartition(Repartitioned)</code></a> (for one input stream) before |
| doing the join and specify the "correct" number of partitions via <a href="Repartitioned.html" title="class in org.apache.kafka.streams.kstream"><code>Repartitioned</code></a> parameter. |
| Furthermore, both input streams need to be co-partitioned on the join key (i.e., use the same partitioner). |
| If this requirement is not met, Kafka Streams will automatically repartition the data, i.e., it will create an |
| internal repartitioning topic in Kafka and write and re-read the data via this topic before the actual join. |
| The repartitioning topic will be named "${applicationId}-<name>-repartition", where "applicationId" is |
| user-specified in <a href="../StreamsConfig.html" title="class in org.apache.kafka.streams"><code>StreamsConfig</code></a> via parameter |
| <a href="../StreamsConfig.html#APPLICATION_ID_CONFIG"><code>APPLICATION_ID_CONFIG</code></a>, "<name>" is an internally generated |
| name, and "-repartition" is a fixed suffix. |
| <p> |
| Repartitioning can happen for one or both of the joining <code>KStream</code>s. |
| For this case, all data of the stream will be redistributed through the repartitioning topic by writing all |
| records to it, and rereading all records from it, such that the join input <code>KStream</code> is partitioned |
| correctly on its key. |
| <p> |
| Both of the joining <code>KStream</code>s will be materialized in local state stores with auto-generated store names, |
| unless a name is provided via a <code>Materialized</code> instance. |
| For failure and recovery each store will be backed by an internal changelog topic that will be created in Kafka. |
| The changelog topic will be named "${applicationId}-<storename>-changelog", where "applicationId" is user-specified |
| in <a href="../StreamsConfig.html" title="class in org.apache.kafka.streams"><code>StreamsConfig</code></a> via parameter <a href="../StreamsConfig.html#APPLICATION_ID_CONFIG"><code>APPLICATION_ID_CONFIG</code></a>, |
| "storeName" is an internally generated name, and "-changelog" is a fixed suffix. |
| <p> |
| You can retrieve all generated internal topic names via <a href="../Topology.html#describe()"><code>Topology.describe()</code></a>.</div> |
| <dl class="notes"> |
| <dt>Type Parameters:</dt> |
| <dd><code>VO</code> - the value type of the other stream</dd> |
| <dd><code>VR</code> - the value type of the result stream</dd> |
| <dt>Parameters:</dt> |
| <dd><code>otherStream</code> - the <code>KStream</code> to be joined with this stream</dd> |
| <dd><code>joiner</code> - a <a href="ValueJoinerWithKey.html" title="interface in org.apache.kafka.streams.kstream"><code>ValueJoinerWithKey</code></a> that computes the join result for a pair of matching records</dd> |
| <dd><code>windows</code> - the specification of the <a href="JoinWindows.html" title="class in org.apache.kafka.streams.kstream"><code>JoinWindows</code></a></dd> |
| <dd><code>streamJoined</code> - a <a href="StreamJoined.html" title="class in org.apache.kafka.streams.kstream"><code>StreamJoined</code></a> instance to configure serdes and state stores</dd> |
| <dt>Returns:</dt> |
| <dd>a <code>KStream</code> that contains join-records for each key and values computed by the given |
| <a href="ValueJoinerWithKey.html" title="interface in org.apache.kafka.streams.kstream"><code>ValueJoinerWithKey</code></a>, one for each matched record-pair with the same key plus one for each non-matching record of |
| this <code>KStream</code> and within the joining window intervals</dd> |
| <dt>See Also:</dt> |
| <dd> |
| <ul class="see-list-long"> |
| <li><a href="#join(org.apache.kafka.streams.kstream.KStream,org.apache.kafka.streams.kstream.ValueJoinerWithKey,org.apache.kafka.streams.kstream.JoinWindows,org.apache.kafka.streams.kstream.StreamJoined)"><code>join(KStream, ValueJoinerWithKey, JoinWindows, StreamJoined)</code></a></li> |
| <li><a href="#outerJoin(org.apache.kafka.streams.kstream.KStream,org.apache.kafka.streams.kstream.ValueJoinerWithKey,org.apache.kafka.streams.kstream.JoinWindows,org.apache.kafka.streams.kstream.StreamJoined)"><code>outerJoin(KStream, ValueJoinerWithKey, JoinWindows, StreamJoined)</code></a></li> |
| </ul> |
| </dd> |
| </dl> |
| </section> |
| </li> |
| <li> |
| <section class="detail" id="outerJoin(org.apache.kafka.streams.kstream.KStream,org.apache.kafka.streams.kstream.ValueJoiner,org.apache.kafka.streams.kstream.JoinWindows)"> |
| <h3>outerJoin</h3> |
| <div class="member-signature"><span class="type-parameters"><VO,<wbr> |
| VR></span> <span class="return-type"><a href="KStream.html" title="interface in org.apache.kafka.streams.kstream">KStream</a><<a href="KStream.html" title="type parameter in KStream">K</a>,<wbr>VR></span> <span class="element-name">outerJoin</span><wbr><span class="parameters">(<a href="KStream.html" title="interface in org.apache.kafka.streams.kstream">KStream</a><<a href="KStream.html" title="type parameter in KStream">K</a>,<wbr>VO> otherStream, |
| <a href="ValueJoiner.html" title="interface in org.apache.kafka.streams.kstream">ValueJoiner</a><? super <a href="KStream.html" title="type parameter in KStream">V</a>,<wbr>? super VO,<wbr>? extends VR> joiner, |
| <a href="JoinWindows.html" title="class in org.apache.kafka.streams.kstream">JoinWindows</a> windows)</span></div> |
| <div class="block">Join records of this stream with another <code>KStream</code>'s records using windowed outer equi join with default |
| serializers and deserializers. |
| In contrast to <a href="#join(org.apache.kafka.streams.kstream.KStream,org.apache.kafka.streams.kstream.ValueJoiner,org.apache.kafka.streams.kstream.JoinWindows)"><code>inner-join</code></a> or |
| <a href="#leftJoin(org.apache.kafka.streams.kstream.KStream,org.apache.kafka.streams.kstream.ValueJoiner,org.apache.kafka.streams.kstream.JoinWindows)"><code>left-join</code></a>, all records from both streams will produce at |
| least one output record (cf. below). |
| The join is computed on the records' key with join attribute <code>thisKStream.key == otherKStream.key</code>. |
| Furthermore, two records are only joined if their timestamps are close to each other as defined by the given |
| <a href="JoinWindows.html" title="class in org.apache.kafka.streams.kstream"><code>JoinWindows</code></a>, i.e., the window defines an additional join predicate on the record timestamps. |
| <p> |
| For each pair of records meeting both join predicates the provided <a href="ValueJoiner.html" title="interface in org.apache.kafka.streams.kstream"><code>ValueJoiner</code></a> will be called to compute |
| a value (with arbitrary type) for the result record. |
| The key of the result record is the same as for both joining input records. |
| Furthermore, for each input record of both <code>KStream</code>s that does not satisfy the join predicate the provided |
| <a href="ValueJoiner.html" title="interface in org.apache.kafka.streams.kstream"><code>ValueJoiner</code></a> will be called with a <code>null</code> value for the this/other stream, respectively. |
| If an input record key or value is <code>null</code> the record will not be included in the join operation and thus no |
| output record will be added to the resulting <code>KStream</code>. |
| <p> |
| Example (assuming all input records belong to the correct windows): |
| <table border='1'> |
| <tr> |
| <th>this</th> |
| <th>other</th> |
| <th>result</th> |
| </tr> |
| <tr> |
| <td><K1:A></td> |
| <td></td> |
| <td><K1:ValueJoiner(A,null)></td> |
| </tr> |
| <tr> |
| <td><K2:B></td> |
| <td><K2:b></td> |
| <td><K2:ValueJoiner(null,b)><br></br><K2:ValueJoiner(B,b)></td> |
| </tr> |
| <tr> |
| <td></td> |
| <td><K3:c></td> |
| <td><K3:ValueJoiner(null,c)></td> |
| </tr> |
| </table> |
| Both input streams (or to be more precise, their underlying source topics) need to have the same number of |
| partitions. |
| If this is not the case, you would need to call <a href="#repartition(org.apache.kafka.streams.kstream.Repartitioned)"><code>repartition(Repartitioned)</code></a> (for one input stream) before |
| doing the join and specify the "correct" number of partitions via <a href="Repartitioned.html" title="class in org.apache.kafka.streams.kstream"><code>Repartitioned</code></a> parameter. |
| Furthermore, both input streams need to be co-partitioned on the join key (i.e., use the same partitioner). |
| If this requirement is not met, Kafka Streams will automatically repartition the data, i.e., it will create an |
| internal repartitioning topic in Kafka and write and re-read the data via this topic before the actual join. |
| The repartitioning topic will be named "${applicationId}-<name>-repartition", where "applicationId" is |
| user-specified in <a href="../StreamsConfig.html" title="class in org.apache.kafka.streams"><code>StreamsConfig</code></a> via parameter |
| <a href="../StreamsConfig.html#APPLICATION_ID_CONFIG"><code>APPLICATION_ID_CONFIG</code></a>, "<name>" is an internally generated |
| name, and "-repartition" is a fixed suffix. |
| <p> |
| Repartitioning can happen for one or both of the joining <code>KStream</code>s. |
| For this case, all data of the stream will be redistributed through the repartitioning topic by writing all |
| records to it, and rereading all records from it, such that the join input <code>KStream</code> is partitioned |
| correctly on its key. |
| <p> |
| Both of the joining <code>KStream</code>s will be materialized in local state stores with auto-generated store names. |
| For failure and recovery each store will be backed by an internal changelog topic that will be created in Kafka. |
| The changelog topic will be named "${applicationId}-<storename>-changelog", where "applicationId" is user-specified |
| in <a href="../StreamsConfig.html" title="class in org.apache.kafka.streams"><code>StreamsConfig</code></a> via parameter <a href="../StreamsConfig.html#APPLICATION_ID_CONFIG"><code>APPLICATION_ID_CONFIG</code></a>, |
| "storeName" is an internally generated name, and "-changelog" is a fixed suffix. |
| <p> |
| You can retrieve all generated internal topic names via <a href="../Topology.html#describe()"><code>Topology.describe()</code></a>.</div> |
| <dl class="notes"> |
| <dt>Type Parameters:</dt> |
| <dd><code>VO</code> - the value type of the other stream</dd> |
| <dd><code>VR</code> - the value type of the result stream</dd> |
| <dt>Parameters:</dt> |
| <dd><code>otherStream</code> - the <code>KStream</code> to be joined with this stream</dd> |
| <dd><code>joiner</code> - a <a href="ValueJoiner.html" title="interface in org.apache.kafka.streams.kstream"><code>ValueJoiner</code></a> that computes the join result for a pair of matching records</dd> |
| <dd><code>windows</code> - the specification of the <a href="JoinWindows.html" title="class in org.apache.kafka.streams.kstream"><code>JoinWindows</code></a></dd> |
| <dt>Returns:</dt> |
| <dd>a <code>KStream</code> that contains join-records for each key and values computed by the given |
| <a href="ValueJoiner.html" title="interface in org.apache.kafka.streams.kstream"><code>ValueJoiner</code></a>, one for each matched record-pair with the same key plus one for each non-matching record of |
| both <code>KStream</code> and within the joining window intervals</dd> |
| <dt>See Also:</dt> |
| <dd> |
| <ul class="see-list-long"> |
| <li><a href="#join(org.apache.kafka.streams.kstream.KStream,org.apache.kafka.streams.kstream.ValueJoiner,org.apache.kafka.streams.kstream.JoinWindows)"><code>join(KStream, ValueJoiner, JoinWindows)</code></a></li> |
| <li><a href="#leftJoin(org.apache.kafka.streams.kstream.KStream,org.apache.kafka.streams.kstream.ValueJoiner,org.apache.kafka.streams.kstream.JoinWindows)"><code>leftJoin(KStream, ValueJoiner, JoinWindows)</code></a></li> |
| </ul> |
| </dd> |
| </dl> |
| </section> |
| </li> |
| <li> |
| <section class="detail" id="outerJoin(org.apache.kafka.streams.kstream.KStream,org.apache.kafka.streams.kstream.ValueJoinerWithKey,org.apache.kafka.streams.kstream.JoinWindows)"> |
| <h3>outerJoin</h3> |
| <div class="member-signature"><span class="type-parameters"><VO,<wbr> |
| VR></span> <span class="return-type"><a href="KStream.html" title="interface in org.apache.kafka.streams.kstream">KStream</a><<a href="KStream.html" title="type parameter in KStream">K</a>,<wbr>VR></span> <span class="element-name">outerJoin</span><wbr><span class="parameters">(<a href="KStream.html" title="interface in org.apache.kafka.streams.kstream">KStream</a><<a href="KStream.html" title="type parameter in KStream">K</a>,<wbr>VO> otherStream, |
| <a href="ValueJoinerWithKey.html" title="interface in org.apache.kafka.streams.kstream">ValueJoinerWithKey</a><? super <a href="KStream.html" title="type parameter in KStream">K</a>,<wbr>? super <a href="KStream.html" title="type parameter in KStream">V</a>,<wbr>? super VO,<wbr>? extends VR> joiner, |
| <a href="JoinWindows.html" title="class in org.apache.kafka.streams.kstream">JoinWindows</a> windows)</span></div> |
| <div class="block">Join records of this stream with another <code>KStream</code>'s records using windowed outer equi join with default |
| serializers and deserializers. |
| In contrast to <a href="#join(org.apache.kafka.streams.kstream.KStream,org.apache.kafka.streams.kstream.ValueJoinerWithKey,org.apache.kafka.streams.kstream.JoinWindows)"><code>inner-join</code></a> or |
| <a href="#leftJoin(org.apache.kafka.streams.kstream.KStream,org.apache.kafka.streams.kstream.ValueJoinerWithKey,org.apache.kafka.streams.kstream.JoinWindows)"><code>left-join</code></a>, all records from both streams will produce at |
| least one output record (cf. below). |
| The join is computed on the records' key with join attribute <code>thisKStream.key == otherKStream.key</code>. |
| Furthermore, two records are only joined if their timestamps are close to each other as defined by the given |
| <a href="JoinWindows.html" title="class in org.apache.kafka.streams.kstream"><code>JoinWindows</code></a>, i.e., the window defines an additional join predicate on the record timestamps. |
| <p> |
| For each pair of records meeting both join predicates the provided <a href="ValueJoinerWithKey.html" title="interface in org.apache.kafka.streams.kstream"><code>ValueJoinerWithKey</code></a> will be called to compute |
| a value (with arbitrary type) for the result record. |
| Note that the key is read-only and should not be modified, as this can lead to undefined behaviour. |
| The key of the result record is the same as for both joining input records. |
| Furthermore, for each input record of both <code>KStream</code>s that does not satisfy the join predicate the provided |
| <a href="ValueJoinerWithKey.html" title="interface in org.apache.kafka.streams.kstream"><code>ValueJoinerWithKey</code></a> will be called with a <code>null</code> value for the this/other stream, respectively. |
| If an input record key or value is <code>null</code> the record will not be included in the join operation and thus no |
| output record will be added to the resulting <code>KStream</code>. |
| <p> |
| Example (assuming all input records belong to the correct windows): |
| <table border='1'> |
| <tr> |
| <th>this</th> |
| <th>other</th> |
| <th>result</th> |
| </tr> |
| <tr> |
| <td><K1:A></td> |
| <td></td> |
| <td><K1:ValueJoinerWithKey(K1,A,null)></td> |
| </tr> |
| <tr> |
| <td><K2:B></td> |
| <td><K2:b></td> |
| <td><K2:ValueJoinerWithKey(K2,null,b)><br></br><K2:ValueJoinerWithKey(K2,B,b)></td> |
| </tr> |
| <tr> |
| <td></td> |
| <td><K3:c></td> |
| <td><K3:ValueJoinerWithKey(K3,null,c)></td> |
| </tr> |
| </table> |
| Both input streams (or to be more precise, their underlying source topics) need to have the same number of |
| partitions. |
| If this is not the case, you would need to call <a href="#repartition(org.apache.kafka.streams.kstream.Repartitioned)"><code>repartition(Repartitioned)</code></a> (for one input stream) before |
| doing the join and specify the "correct" number of partitions via <a href="Repartitioned.html" title="class in org.apache.kafka.streams.kstream"><code>Repartitioned</code></a> parameter. |
| Furthermore, both input streams need to be co-partitioned on the join key (i.e., use the same partitioner). |
| If this requirement is not met, Kafka Streams will automatically repartition the data, i.e., it will create an |
| internal repartitioning topic in Kafka and write and re-read the data via this topic before the actual join. |
| The repartitioning topic will be named "${applicationId}-<name>-repartition", where "applicationId" is |
| user-specified in <a href="../StreamsConfig.html" title="class in org.apache.kafka.streams"><code>StreamsConfig</code></a> via parameter |
| <a href="../StreamsConfig.html#APPLICATION_ID_CONFIG"><code>APPLICATION_ID_CONFIG</code></a>, "<name>" is an internally generated |
| name, and "-repartition" is a fixed suffix. |
| <p> |
| Repartitioning can happen for one or both of the joining <code>KStream</code>s. |
| For this case, all data of the stream will be redistributed through the repartitioning topic by writing all |
| records to it, and rereading all records from it, such that the join input <code>KStream</code> is partitioned |
| correctly on its key. |
| <p> |
| Both of the joining <code>KStream</code>s will be materialized in local state stores with auto-generated store names. |
| For failure and recovery each store will be backed by an internal changelog topic that will be created in Kafka. |
| The changelog topic will be named "${applicationId}-<storename>-changelog", where "applicationId" is user-specified |
| in <a href="../StreamsConfig.html" title="class in org.apache.kafka.streams"><code>StreamsConfig</code></a> via parameter <a href="../StreamsConfig.html#APPLICATION_ID_CONFIG"><code>APPLICATION_ID_CONFIG</code></a>, |
| "storeName" is an internally generated name, and "-changelog" is a fixed suffix. |
| <p> |
| You can retrieve all generated internal topic names via <a href="../Topology.html#describe()"><code>Topology.describe()</code></a>.</div> |
| <dl class="notes"> |
| <dt>Type Parameters:</dt> |
| <dd><code>VO</code> - the value type of the other stream</dd> |
| <dd><code>VR</code> - the value type of the result stream</dd> |
| <dt>Parameters:</dt> |
| <dd><code>otherStream</code> - the <code>KStream</code> to be joined with this stream</dd> |
| <dd><code>joiner</code> - a <a href="ValueJoinerWithKey.html" title="interface in org.apache.kafka.streams.kstream"><code>ValueJoinerWithKey</code></a> that computes the join result for a pair of matching records</dd> |
| <dd><code>windows</code> - the specification of the <a href="JoinWindows.html" title="class in org.apache.kafka.streams.kstream"><code>JoinWindows</code></a></dd> |
| <dt>Returns:</dt> |
| <dd>a <code>KStream</code> that contains join-records for each key and values computed by the given |
| <a href="ValueJoinerWithKey.html" title="interface in org.apache.kafka.streams.kstream"><code>ValueJoinerWithKey</code></a>, one for each matched record-pair with the same key plus one for each non-matching record of |
| both <code>KStream</code> and within the joining window intervals</dd> |
| <dt>See Also:</dt> |
| <dd> |
| <ul class="see-list-long"> |
| <li><a href="#join(org.apache.kafka.streams.kstream.KStream,org.apache.kafka.streams.kstream.ValueJoinerWithKey,org.apache.kafka.streams.kstream.JoinWindows)"><code>join(KStream, ValueJoinerWithKey, JoinWindows)</code></a></li> |
| <li><a href="#leftJoin(org.apache.kafka.streams.kstream.KStream,org.apache.kafka.streams.kstream.ValueJoinerWithKey,org.apache.kafka.streams.kstream.JoinWindows)"><code>leftJoin(KStream, ValueJoinerWithKey, JoinWindows)</code></a></li> |
| </ul> |
| </dd> |
| </dl> |
| </section> |
| </li> |
| <li> |
| <section class="detail" id="outerJoin(org.apache.kafka.streams.kstream.KStream,org.apache.kafka.streams.kstream.ValueJoiner,org.apache.kafka.streams.kstream.JoinWindows,org.apache.kafka.streams.kstream.StreamJoined)"> |
| <h3>outerJoin</h3> |
| <div class="member-signature"><span class="type-parameters"><VO,<wbr> |
| VR></span> <span class="return-type"><a href="KStream.html" title="interface in org.apache.kafka.streams.kstream">KStream</a><<a href="KStream.html" title="type parameter in KStream">K</a>,<wbr>VR></span> <span class="element-name">outerJoin</span><wbr><span class="parameters">(<a href="KStream.html" title="interface in org.apache.kafka.streams.kstream">KStream</a><<a href="KStream.html" title="type parameter in KStream">K</a>,<wbr>VO> otherStream, |
| <a href="ValueJoiner.html" title="interface in org.apache.kafka.streams.kstream">ValueJoiner</a><? super <a href="KStream.html" title="type parameter in KStream">V</a>,<wbr>? super VO,<wbr>? extends VR> joiner, |
| <a href="JoinWindows.html" title="class in org.apache.kafka.streams.kstream">JoinWindows</a> windows, |
| <a href="StreamJoined.html" title="class in org.apache.kafka.streams.kstream">StreamJoined</a><<a href="KStream.html" title="type parameter in KStream">K</a>,<wbr><a href="KStream.html" title="type parameter in KStream">V</a>,<wbr>VO> streamJoined)</span></div> |
| <div class="block">Join records of this stream with another <code>KStream</code>'s records using windowed outer equi join using the |
| <a href="StreamJoined.html" title="class in org.apache.kafka.streams.kstream"><code>StreamJoined</code></a> instance for configuration of the <a href="../../common/serialization/Serde.html" title="interface in org.apache.kafka.common.serialization"><code>key serde</code></a>, <a href="../../common/serialization/Serde.html" title="interface in org.apache.kafka.common.serialization"><code>this stream's value |
| serde</code></a>, <a href="../../common/serialization/Serde.html" title="interface in org.apache.kafka.common.serialization"><code>the other stream's value serde</code></a>, and used state stores. |
| In contrast to <a href="#join(org.apache.kafka.streams.kstream.KStream,org.apache.kafka.streams.kstream.ValueJoiner,org.apache.kafka.streams.kstream.JoinWindows)"><code>inner-join</code></a> or |
| <a href="#leftJoin(org.apache.kafka.streams.kstream.KStream,org.apache.kafka.streams.kstream.ValueJoiner,org.apache.kafka.streams.kstream.JoinWindows)"><code>left-join</code></a>, all records from both streams will produce at |
| least one output record (cf. below). |
| The join is computed on the records' key with join attribute <code>thisKStream.key == otherKStream.key</code>. |
| Furthermore, two records are only joined if their timestamps are close to each other as defined by the given |
| <a href="JoinWindows.html" title="class in org.apache.kafka.streams.kstream"><code>JoinWindows</code></a>, i.e., the window defines an additional join predicate on the record timestamps. |
| <p> |
| For each pair of records meeting both join predicates the provided <a href="ValueJoiner.html" title="interface in org.apache.kafka.streams.kstream"><code>ValueJoiner</code></a> will be called to compute |
| a value (with arbitrary type) for the result record. |
| The key of the result record is the same as for both joining input records. |
| Furthermore, for each input record of both <code>KStream</code>s that does not satisfy the join predicate the provided |
| <a href="ValueJoiner.html" title="interface in org.apache.kafka.streams.kstream"><code>ValueJoiner</code></a> will be called with a <code>null</code> value for this/other stream, respectively. |
| If an input record key or value is <code>null</code> the record will not be included in the join operation and thus no |
| output record will be added to the resulting <code>KStream</code>. |
| <p> |
| Example (assuming all input records belong to the correct windows): |
| <table border='1'> |
| <tr> |
| <th>this</th> |
| <th>other</th> |
| <th>result</th> |
| </tr> |
| <tr> |
| <td><K1:A></td> |
| <td></td> |
| <td><K1:ValueJoiner(A,null)></td> |
| </tr> |
| <tr> |
| <td><K2:B></td> |
| <td><K2:b></td> |
| <td><K2:ValueJoiner(null,b)><br></br><K2:ValueJoiner(B,b)></td> |
| </tr> |
| <tr> |
| <td></td> |
| <td><K3:c></td> |
| <td><K3:ValueJoiner(null,c)></td> |
| </tr> |
| </table> |
| Both input streams (or to be more precise, their underlying source topics) need to have the same number of |
| partitions. |
| If this is not the case, you would need to call <a href="#repartition(org.apache.kafka.streams.kstream.Repartitioned)"><code>repartition(Repartitioned)</code></a> (for one input stream) before |
| doing the join and specify the "correct" number of partitions via <a href="Repartitioned.html" title="class in org.apache.kafka.streams.kstream"><code>Repartitioned</code></a> parameter. |
| Furthermore, both input streams need to be co-partitioned on the join key (i.e., use the same partitioner). |
| If this requirement is not met, Kafka Streams will automatically repartition the data, i.e., it will create an |
| internal repartitioning topic in Kafka and write and re-read the data via this topic before the actual join. |
| The repartitioning topic will be named "${applicationId}-<name>-repartition", where "applicationId" is |
| user-specified in <a href="../StreamsConfig.html" title="class in org.apache.kafka.streams"><code>StreamsConfig</code></a> via parameter |
| <a href="../StreamsConfig.html#APPLICATION_ID_CONFIG"><code>APPLICATION_ID_CONFIG</code></a>, "<name>" is an internally generated |
| name, and "-repartition" is a fixed suffix. |
| <p> |
| Repartitioning can happen for one or both of the joining <code>KStream</code>s. |
| For this case, all data of the stream will be redistributed through the repartitioning topic by writing all |
| records to it, and rereading all records from it, such that the join input <code>KStream</code> is partitioned |
| correctly on its key. |
| <p> |
| Both of the joining <code>KStream</code>s will be materialized in local state stores with auto-generated store names, |
| unless a name is provided via a <code>Materialized</code> instance. |
| For failure and recovery each store will be backed by an internal changelog topic that will be created in Kafka. |
| The changelog topic will be named "${applicationId}-<storename>-changelog", where "applicationId" is user-specified |
| in <a href="../StreamsConfig.html" title="class in org.apache.kafka.streams"><code>StreamsConfig</code></a> via parameter <a href="../StreamsConfig.html#APPLICATION_ID_CONFIG"><code>APPLICATION_ID_CONFIG</code></a>, |
| "storeName" is an internally generated name, and "-changelog" is a fixed suffix. |
| <p> |
| You can retrieve all generated internal topic names via <a href="../Topology.html#describe()"><code>Topology.describe()</code></a>.</div> |
| <dl class="notes"> |
| <dt>Type Parameters:</dt> |
| <dd><code>VO</code> - the value type of the other stream</dd> |
| <dd><code>VR</code> - the value type of the result stream</dd> |
| <dt>Parameters:</dt> |
| <dd><code>otherStream</code> - the <code>KStream</code> to be joined with this stream</dd> |
| <dd><code>joiner</code> - a <a href="ValueJoiner.html" title="interface in org.apache.kafka.streams.kstream"><code>ValueJoiner</code></a> that computes the join result for a pair of matching records</dd> |
| <dd><code>windows</code> - the specification of the <a href="JoinWindows.html" title="class in org.apache.kafka.streams.kstream"><code>JoinWindows</code></a></dd> |
| <dd><code>streamJoined</code> - a <a href="StreamJoined.html" title="class in org.apache.kafka.streams.kstream"><code>StreamJoined</code></a> instance to configure serdes and state stores</dd> |
| <dt>Returns:</dt> |
| <dd>a <code>KStream</code> that contains join-records for each key and values computed by the given |
| <a href="ValueJoiner.html" title="interface in org.apache.kafka.streams.kstream"><code>ValueJoiner</code></a>, one for each matched record-pair with the same key plus one for each non-matching record of |
| both <code>KStream</code> and within the joining window intervals</dd> |
| <dt>See Also:</dt> |
| <dd> |
| <ul class="see-list-long"> |
| <li><a href="#join(org.apache.kafka.streams.kstream.KStream,org.apache.kafka.streams.kstream.ValueJoiner,org.apache.kafka.streams.kstream.JoinWindows,org.apache.kafka.streams.kstream.StreamJoined)"><code>join(KStream, ValueJoiner, JoinWindows, StreamJoined)</code></a></li> |
| <li><a href="#leftJoin(org.apache.kafka.streams.kstream.KStream,org.apache.kafka.streams.kstream.ValueJoiner,org.apache.kafka.streams.kstream.JoinWindows,org.apache.kafka.streams.kstream.StreamJoined)"><code>leftJoin(KStream, ValueJoiner, JoinWindows, StreamJoined)</code></a></li> |
| </ul> |
| </dd> |
| </dl> |
| </section> |
| </li> |
| <li> |
| <section class="detail" id="outerJoin(org.apache.kafka.streams.kstream.KStream,org.apache.kafka.streams.kstream.ValueJoinerWithKey,org.apache.kafka.streams.kstream.JoinWindows,org.apache.kafka.streams.kstream.StreamJoined)"> |
| <h3>outerJoin</h3> |
| <div class="member-signature"><span class="type-parameters"><VO,<wbr> |
| VR></span> <span class="return-type"><a href="KStream.html" title="interface in org.apache.kafka.streams.kstream">KStream</a><<a href="KStream.html" title="type parameter in KStream">K</a>,<wbr>VR></span> <span class="element-name">outerJoin</span><wbr><span class="parameters">(<a href="KStream.html" title="interface in org.apache.kafka.streams.kstream">KStream</a><<a href="KStream.html" title="type parameter in KStream">K</a>,<wbr>VO> otherStream, |
| <a href="ValueJoinerWithKey.html" title="interface in org.apache.kafka.streams.kstream">ValueJoinerWithKey</a><? super <a href="KStream.html" title="type parameter in KStream">K</a>,<wbr>? super <a href="KStream.html" title="type parameter in KStream">V</a>,<wbr>? super VO,<wbr>? extends VR> joiner, |
| <a href="JoinWindows.html" title="class in org.apache.kafka.streams.kstream">JoinWindows</a> windows, |
| <a href="StreamJoined.html" title="class in org.apache.kafka.streams.kstream">StreamJoined</a><<a href="KStream.html" title="type parameter in KStream">K</a>,<wbr><a href="KStream.html" title="type parameter in KStream">V</a>,<wbr>VO> streamJoined)</span></div> |
| <div class="block">Join records of this stream with another <code>KStream</code>'s records using windowed outer equi join using the |
| <a href="StreamJoined.html" title="class in org.apache.kafka.streams.kstream"><code>StreamJoined</code></a> instance for configuration of the <a href="../../common/serialization/Serde.html" title="interface in org.apache.kafka.common.serialization"><code>key serde</code></a>, <a href="../../common/serialization/Serde.html" title="interface in org.apache.kafka.common.serialization"><code>this stream's value |
| serde</code></a>, <a href="../../common/serialization/Serde.html" title="interface in org.apache.kafka.common.serialization"><code>the other stream's value serde</code></a>, and used state stores. |
| In contrast to <a href="#join(org.apache.kafka.streams.kstream.KStream,org.apache.kafka.streams.kstream.ValueJoinerWithKey,org.apache.kafka.streams.kstream.JoinWindows)"><code>inner-join</code></a> or |
| <a href="#leftJoin(org.apache.kafka.streams.kstream.KStream,org.apache.kafka.streams.kstream.ValueJoinerWithKey,org.apache.kafka.streams.kstream.JoinWindows)"><code>left-join</code></a>, all records from both streams will produce at |
| least one output record (cf. below). |
| The join is computed on the records' key with join attribute <code>thisKStream.key == otherKStream.key</code>. |
| Furthermore, two records are only joined if their timestamps are close to each other as defined by the given |
| <a href="JoinWindows.html" title="class in org.apache.kafka.streams.kstream"><code>JoinWindows</code></a>, i.e., the window defines an additional join predicate on the record timestamps. |
| <p> |
| For each pair of records meeting both join predicates the provided <a href="ValueJoinerWithKey.html" title="interface in org.apache.kafka.streams.kstream"><code>ValueJoinerWithKey</code></a> will be called to compute |
| a value (with arbitrary type) for the result record. |
| Note that the key is read-only and should not be modified, as this can lead to undefined behaviour. |
| The key of the result record is the same as for both joining input records. |
| Furthermore, for each input record of both <code>KStream</code>s that does not satisfy the join predicate the provided |
| <a href="ValueJoinerWithKey.html" title="interface in org.apache.kafka.streams.kstream"><code>ValueJoinerWithKey</code></a> will be called with a <code>null</code> value for this/other stream, respectively. |
| If an input record key or value is <code>null</code> the record will not be included in the join operation and thus no |
| output record will be added to the resulting <code>KStream</code>. |
| <p> |
| Example (assuming all input records belong to the correct windows): |
| <table border='1'> |
| <tr> |
| <th>this</th> |
| <th>other</th> |
| <th>result</th> |
| </tr> |
| <tr> |
| <td><K1:A></td> |
| <td></td> |
| <td><K1:ValueJoinerWithKey(K1,A,null)></td> |
| </tr> |
| <tr> |
| <td><K2:B></td> |
| <td><K2:b></td> |
| <td><K2:ValueJoinerWithKey(K2,null,b)><br></br><K2:ValueJoinerWithKey(K2,B,b)></td> |
| </tr> |
| <tr> |
| <td></td> |
| <td><K3:c></td> |
| <td><K3:ValueJoinerWithKey(K3,null,c)></td> |
| </tr> |
| </table> |
| Both input streams (or to be more precise, their underlying source topics) need to have the same number of |
| partitions. |
| If this is not the case, you would need to call <a href="#repartition(org.apache.kafka.streams.kstream.Repartitioned)"><code>repartition(Repartitioned)</code></a> (for one input stream) before |
| doing the join and specify the "correct" number of partitions via <a href="Repartitioned.html" title="class in org.apache.kafka.streams.kstream"><code>Repartitioned</code></a> parameter. |
| Furthermore, both input streams need to be co-partitioned on the join key (i.e., use the same partitioner). |
| If this requirement is not met, Kafka Streams will automatically repartition the data, i.e., it will create an |
| internal repartitioning topic in Kafka and write and re-read the data via this topic before the actual join. |
| The repartitioning topic will be named "${applicationId}-<name>-repartition", where "applicationId" is |
| user-specified in <a href="../StreamsConfig.html" title="class in org.apache.kafka.streams"><code>StreamsConfig</code></a> via parameter |
| <a href="../StreamsConfig.html#APPLICATION_ID_CONFIG"><code>APPLICATION_ID_CONFIG</code></a>, "<name>" is an internally generated |
| name, and "-repartition" is a fixed suffix. |
| <p> |
| Repartitioning can happen for one or both of the joining <code>KStream</code>s. |
| For this case, all data of the stream will be redistributed through the repartitioning topic by writing all |
| records to it, and rereading all records from it, such that the join input <code>KStream</code> is partitioned |
| correctly on its key. |
| <p> |
| Both of the joining <code>KStream</code>s will be materialized in local state stores with auto-generated store names, |
| unless a name is provided via a <code>Materialized</code> instance. |
| For failure and recovery each store will be backed by an internal changelog topic that will be created in Kafka. |
| The changelog topic will be named "${applicationId}-<storename>-changelog", where "applicationId" is user-specified |
| in <a href="../StreamsConfig.html" title="class in org.apache.kafka.streams"><code>StreamsConfig</code></a> via parameter <a href="../StreamsConfig.html#APPLICATION_ID_CONFIG"><code>APPLICATION_ID_CONFIG</code></a>, |
| "storeName" is an internally generated name, and "-changelog" is a fixed suffix. |
| <p> |
| You can retrieve all generated internal topic names via <a href="../Topology.html#describe()"><code>Topology.describe()</code></a>.</div> |
| <dl class="notes"> |
| <dt>Type Parameters:</dt> |
| <dd><code>VO</code> - the value type of the other stream</dd> |
| <dd><code>VR</code> - the value type of the result stream</dd> |
| <dt>Parameters:</dt> |
| <dd><code>otherStream</code> - the <code>KStream</code> to be joined with this stream</dd> |
| <dd><code>joiner</code> - a <a href="ValueJoinerWithKey.html" title="interface in org.apache.kafka.streams.kstream"><code>ValueJoinerWithKey</code></a> that computes the join result for a pair of matching records</dd> |
| <dd><code>windows</code> - the specification of the <a href="JoinWindows.html" title="class in org.apache.kafka.streams.kstream"><code>JoinWindows</code></a></dd> |
| <dd><code>streamJoined</code> - a <a href="StreamJoined.html" title="class in org.apache.kafka.streams.kstream"><code>StreamJoined</code></a> instance to configure serdes and state stores</dd> |
| <dt>Returns:</dt> |
| <dd>a <code>KStream</code> that contains join-records for each key and values computed by the given |
| <a href="ValueJoinerWithKey.html" title="interface in org.apache.kafka.streams.kstream"><code>ValueJoinerWithKey</code></a>, one for each matched record-pair with the same key plus one for each non-matching record of |
| both <code>KStream</code> and within the joining window intervals</dd> |
| <dt>See Also:</dt> |
| <dd> |
| <ul class="see-list-long"> |
| <li><a href="#join(org.apache.kafka.streams.kstream.KStream,org.apache.kafka.streams.kstream.ValueJoinerWithKey,org.apache.kafka.streams.kstream.JoinWindows,org.apache.kafka.streams.kstream.StreamJoined)"><code>join(KStream, ValueJoinerWithKey, JoinWindows, StreamJoined)</code></a></li> |
| <li><a href="#leftJoin(org.apache.kafka.streams.kstream.KStream,org.apache.kafka.streams.kstream.ValueJoinerWithKey,org.apache.kafka.streams.kstream.JoinWindows,org.apache.kafka.streams.kstream.StreamJoined)"><code>leftJoin(KStream, ValueJoinerWithKey, JoinWindows, StreamJoined)</code></a></li> |
| </ul> |
| </dd> |
| </dl> |
| </section> |
| </li> |
| <li> |
| <section class="detail" id="join(org.apache.kafka.streams.kstream.KTable,org.apache.kafka.streams.kstream.ValueJoiner)"> |
| <h3>join</h3> |
| <div class="member-signature"><span class="type-parameters"><VT,<wbr> |
| VR></span> <span class="return-type"><a href="KStream.html" title="interface in org.apache.kafka.streams.kstream">KStream</a><<a href="KStream.html" title="type parameter in KStream">K</a>,<wbr>VR></span> <span class="element-name">join</span><wbr><span class="parameters">(<a href="KTable.html" title="interface in org.apache.kafka.streams.kstream">KTable</a><<a href="KStream.html" title="type parameter in KStream">K</a>,<wbr>VT> table, |
| <a href="ValueJoiner.html" title="interface in org.apache.kafka.streams.kstream">ValueJoiner</a><? super <a href="KStream.html" title="type parameter in KStream">V</a>,<wbr>? super VT,<wbr>? extends VR> joiner)</span></div> |
| <div class="block">Join records of this stream with <a href="KTable.html" title="interface in org.apache.kafka.streams.kstream"><code>KTable</code></a>'s records using non-windowed inner equi join with default |
| serializers and deserializers. |
| The join is a primary key table lookup join with join attribute <code>stream.key == table.key</code>. |
| "Table lookup join" means, that results are only computed if <code>KStream</code> records are processed. |
| This is done by performing a lookup for matching records in the <em>current</em> (i.e., processing time) internal |
| <a href="KTable.html" title="interface in org.apache.kafka.streams.kstream"><code>KTable</code></a> state. |
| In contrast, processing <a href="KTable.html" title="interface in org.apache.kafka.streams.kstream"><code>KTable</code></a> input records will only update the internal <a href="KTable.html" title="interface in org.apache.kafka.streams.kstream"><code>KTable</code></a> state and |
| will not produce any result records. |
| <p> |
| For each <code>KStream</code> record that finds a corresponding record in <a href="KTable.html" title="interface in org.apache.kafka.streams.kstream"><code>KTable</code></a> the provided |
| <a href="ValueJoiner.html" title="interface in org.apache.kafka.streams.kstream"><code>ValueJoiner</code></a> will be called to compute a value (with arbitrary type) for the result record. |
| The key of the result record is the same as for both joining input records. |
| If an <code>KStream</code> input record key or value is <code>null</code> the record will not be included in the join |
| operation and thus no output record will be added to the resulting <code>KStream</code>. |
| <p> |
| Example: |
| <table border='1'> |
| <tr> |
| <th>KStream</th> |
| <th>KTable</th> |
| <th>state</th> |
| <th>result</th> |
| </tr> |
| <tr> |
| <td><K1:A></td> |
| <td></td> |
| <td></td> |
| <td></td> |
| </tr> |
| <tr> |
| <td></td> |
| <td><K1:b></td> |
| <td><K1:b></td> |
| <td></td> |
| </tr> |
| <tr> |
| <td><K1:C></td> |
| <td></td> |
| <td><K1:b></td> |
| <td><K1:ValueJoiner(C,b)></td> |
| </tr> |
| </table> |
| Both input streams (or to be more precise, their underlying source topics) need to have the same number of |
| partitions. |
| If this is not the case, you would need to call <a href="#repartition(org.apache.kafka.streams.kstream.Repartitioned)"><code>repartition(Repartitioned)</code></a> for this <code>KStream</code> |
| before doing the join, specifying the same number of partitions via <a href="Repartitioned.html" title="class in org.apache.kafka.streams.kstream"><code>Repartitioned</code></a> parameter as the given |
| <a href="KTable.html" title="interface in org.apache.kafka.streams.kstream"><code>KTable</code></a>. |
| Furthermore, both input streams need to be co-partitioned on the join key (i.e., use the same partitioner); |
| cf. <a href="#join(org.apache.kafka.streams.kstream.GlobalKTable,org.apache.kafka.streams.kstream.KeyValueMapper,org.apache.kafka.streams.kstream.ValueJoiner)"><code>join(GlobalKTable, KeyValueMapper, ValueJoiner)</code></a>. |
| If this requirement is not met, Kafka Streams will automatically repartition the data, i.e., it will create an |
| internal repartitioning topic in Kafka and write and re-read the data via this topic before the actual join. |
| The repartitioning topic will be named "${applicationId}-<name>-repartition", where "applicationId" is |
| user-specified in <a href="../StreamsConfig.html" title="class in org.apache.kafka.streams"><code>StreamsConfig</code></a> via parameter |
| <a href="../StreamsConfig.html#APPLICATION_ID_CONFIG"><code>APPLICATION_ID_CONFIG</code></a>, "<name>" is an internally generated |
| name, and "-repartition" is a fixed suffix. |
| <p> |
| You can retrieve all generated internal topic names via <a href="../Topology.html#describe()"><code>Topology.describe()</code></a>. |
| <p> |
| Repartitioning can happen only for this <code>KStream</code> but not for the provided <a href="KTable.html" title="interface in org.apache.kafka.streams.kstream"><code>KTable</code></a>. |
| For this case, all data of the stream will be redistributed through the repartitioning topic by writing all |
| records to it, and rereading all records from it, such that the join input <code>KStream</code> is partitioned |
| correctly on its key.</div> |
| <dl class="notes"> |
| <dt>Type Parameters:</dt> |
| <dd><code>VT</code> - the value type of the table</dd> |
| <dd><code>VR</code> - the value type of the result stream</dd> |
| <dt>Parameters:</dt> |
| <dd><code>table</code> - the <a href="KTable.html" title="interface in org.apache.kafka.streams.kstream"><code>KTable</code></a> to be joined with this stream</dd> |
| <dd><code>joiner</code> - a <a href="ValueJoiner.html" title="interface in org.apache.kafka.streams.kstream"><code>ValueJoiner</code></a> that computes the join result for a pair of matching records</dd> |
| <dt>Returns:</dt> |
| <dd>a <code>KStream</code> that contains join-records for each key and values computed by the given |
| <a href="ValueJoiner.html" title="interface in org.apache.kafka.streams.kstream"><code>ValueJoiner</code></a>, one for each matched record-pair with the same key</dd> |
| <dt>See Also:</dt> |
| <dd> |
| <ul class="see-list-long"> |
| <li><a href="#leftJoin(org.apache.kafka.streams.kstream.KTable,org.apache.kafka.streams.kstream.ValueJoiner)"><code>leftJoin(KTable, ValueJoiner)</code></a></li> |
| <li><a href="#join(org.apache.kafka.streams.kstream.GlobalKTable,org.apache.kafka.streams.kstream.KeyValueMapper,org.apache.kafka.streams.kstream.ValueJoiner)"><code>join(GlobalKTable, KeyValueMapper, ValueJoiner)</code></a></li> |
| </ul> |
| </dd> |
| </dl> |
| </section> |
| </li> |
| <li> |
| <section class="detail" id="join(org.apache.kafka.streams.kstream.KTable,org.apache.kafka.streams.kstream.ValueJoinerWithKey)"> |
| <h3>join</h3> |
| <div class="member-signature"><span class="type-parameters"><VT,<wbr> |
| VR></span> <span class="return-type"><a href="KStream.html" title="interface in org.apache.kafka.streams.kstream">KStream</a><<a href="KStream.html" title="type parameter in KStream">K</a>,<wbr>VR></span> <span class="element-name">join</span><wbr><span class="parameters">(<a href="KTable.html" title="interface in org.apache.kafka.streams.kstream">KTable</a><<a href="KStream.html" title="type parameter in KStream">K</a>,<wbr>VT> table, |
| <a href="ValueJoinerWithKey.html" title="interface in org.apache.kafka.streams.kstream">ValueJoinerWithKey</a><? super <a href="KStream.html" title="type parameter in KStream">K</a>,<wbr>? super <a href="KStream.html" title="type parameter in KStream">V</a>,<wbr>? super VT,<wbr>? extends VR> joiner)</span></div> |
| <div class="block">Join records of this stream with <a href="KTable.html" title="interface in org.apache.kafka.streams.kstream"><code>KTable</code></a>'s records using non-windowed inner equi join with default |
| serializers and deserializers. |
| The join is a primary key table lookup join with join attribute <code>stream.key == table.key</code>. |
| "Table lookup join" means, that results are only computed if <code>KStream</code> records are processed. |
| This is done by performing a lookup for matching records in the <em>current</em> (i.e., processing time) internal |
| <a href="KTable.html" title="interface in org.apache.kafka.streams.kstream"><code>KTable</code></a> state. |
| In contrast, processing <a href="KTable.html" title="interface in org.apache.kafka.streams.kstream"><code>KTable</code></a> input records will only update the internal <a href="KTable.html" title="interface in org.apache.kafka.streams.kstream"><code>KTable</code></a> state and |
| will not produce any result records. |
| <p> |
| For each <code>KStream</code> record that finds a corresponding record in <a href="KTable.html" title="interface in org.apache.kafka.streams.kstream"><code>KTable</code></a> the provided |
| <a href="ValueJoinerWithKey.html" title="interface in org.apache.kafka.streams.kstream"><code>ValueJoinerWithKey</code></a> will be called to compute a value (with arbitrary type) for the result record. |
| Note that the key is read-only and should not be modified, as this can lead to undefined behaviour. |
| |
| The key of the result record is the same as for both joining input records. |
| If an <code>KStream</code> input record key or value is <code>null</code> the record will not be included in the join |
| operation and thus no output record will be added to the resulting <code>KStream</code>. |
| <p> |
| Example: |
| <table border='1'> |
| <tr> |
| <th>KStream</th> |
| <th>KTable</th> |
| <th>state</th> |
| <th>result</th> |
| </tr> |
| <tr> |
| <td><K1:A></td> |
| <td></td> |
| <td></td> |
| <td></td> |
| </tr> |
| <tr> |
| <td></td> |
| <td><K1:b></td> |
| <td><K1:b></td> |
| <td></td> |
| </tr> |
| <tr> |
| <td><K1:C></td> |
| <td></td> |
| <td><K1:b></td> |
| <td><K1:ValueJoinerWithKey(K1,C,b)></td> |
| </tr> |
| </table> |
| Both input streams (or to be more precise, their underlying source topics) need to have the same number of |
| partitions. |
| If this is not the case, you would need to call <a href="#repartition(org.apache.kafka.streams.kstream.Repartitioned)"><code>repartition(Repartitioned)</code></a> for this <code>KStream</code> |
| before doing the join, specifying the same number of partitions via <a href="Repartitioned.html" title="class in org.apache.kafka.streams.kstream"><code>Repartitioned</code></a> parameter as the given |
| <a href="KTable.html" title="interface in org.apache.kafka.streams.kstream"><code>KTable</code></a>. |
| Furthermore, both input streams need to be co-partitioned on the join key (i.e., use the same partitioner); |
| cf. <a href="#join(org.apache.kafka.streams.kstream.GlobalKTable,org.apache.kafka.streams.kstream.KeyValueMapper,org.apache.kafka.streams.kstream.ValueJoinerWithKey)"><code>join(GlobalKTable, KeyValueMapper, ValueJoinerWithKey)</code></a>. |
| If this requirement is not met, Kafka Streams will automatically repartition the data, i.e., it will create an |
| internal repartitioning topic in Kafka and write and re-read the data via this topic before the actual join. |
| The repartitioning topic will be named "${applicationId}-<name>-repartition", where "applicationId" is |
| user-specified in <a href="../StreamsConfig.html" title="class in org.apache.kafka.streams"><code>StreamsConfig</code></a> via parameter |
| <a href="../StreamsConfig.html#APPLICATION_ID_CONFIG"><code>APPLICATION_ID_CONFIG</code></a>, "<name>" is an internally generated |
| name, and "-repartition" is a fixed suffix. |
| <p> |
| You can retrieve all generated internal topic names via <a href="../Topology.html#describe()"><code>Topology.describe()</code></a>. |
| <p> |
| Repartitioning can happen only for this <code>KStream</code> but not for the provided <a href="KTable.html" title="interface in org.apache.kafka.streams.kstream"><code>KTable</code></a>. |
| For this case, all data of the stream will be redistributed through the repartitioning topic by writing all |
| records to it, and rereading all records from it, such that the join input <code>KStream</code> is partitioned |
| correctly on its key.</div> |
| <dl class="notes"> |
| <dt>Type Parameters:</dt> |
| <dd><code>VT</code> - the value type of the table</dd> |
| <dd><code>VR</code> - the value type of the result stream</dd> |
| <dt>Parameters:</dt> |
| <dd><code>table</code> - the <a href="KTable.html" title="interface in org.apache.kafka.streams.kstream"><code>KTable</code></a> to be joined with this stream</dd> |
| <dd><code>joiner</code> - a <a href="ValueJoinerWithKey.html" title="interface in org.apache.kafka.streams.kstream"><code>ValueJoinerWithKey</code></a> that computes the join result for a pair of matching records</dd> |
| <dt>Returns:</dt> |
| <dd>a <code>KStream</code> that contains join-records for each key and values computed by the given |
| <a href="ValueJoinerWithKey.html" title="interface in org.apache.kafka.streams.kstream"><code>ValueJoinerWithKey</code></a>, one for each matched record-pair with the same key</dd> |
| <dt>See Also:</dt> |
| <dd> |
| <ul class="see-list-long"> |
| <li><a href="#leftJoin(org.apache.kafka.streams.kstream.KTable,org.apache.kafka.streams.kstream.ValueJoinerWithKey)"><code>leftJoin(KTable, ValueJoinerWithKey)</code></a></li> |
| <li><a href="#join(org.apache.kafka.streams.kstream.GlobalKTable,org.apache.kafka.streams.kstream.KeyValueMapper,org.apache.kafka.streams.kstream.ValueJoinerWithKey)"><code>join(GlobalKTable, KeyValueMapper, ValueJoinerWithKey)</code></a></li> |
| </ul> |
| </dd> |
| </dl> |
| </section> |
| </li> |
| <li> |
| <section class="detail" id="join(org.apache.kafka.streams.kstream.KTable,org.apache.kafka.streams.kstream.ValueJoiner,org.apache.kafka.streams.kstream.Joined)"> |
| <h3>join</h3> |
| <div class="member-signature"><span class="type-parameters"><VT,<wbr> |
| VR></span> <span class="return-type"><a href="KStream.html" title="interface in org.apache.kafka.streams.kstream">KStream</a><<a href="KStream.html" title="type parameter in KStream">K</a>,<wbr>VR></span> <span class="element-name">join</span><wbr><span class="parameters">(<a href="KTable.html" title="interface in org.apache.kafka.streams.kstream">KTable</a><<a href="KStream.html" title="type parameter in KStream">K</a>,<wbr>VT> table, |
| <a href="ValueJoiner.html" title="interface in org.apache.kafka.streams.kstream">ValueJoiner</a><? super <a href="KStream.html" title="type parameter in KStream">V</a>,<wbr>? super VT,<wbr>? extends VR> joiner, |
| <a href="Joined.html" title="class in org.apache.kafka.streams.kstream">Joined</a><<a href="KStream.html" title="type parameter in KStream">K</a>,<wbr><a href="KStream.html" title="type parameter in KStream">V</a>,<wbr>VT> joined)</span></div> |
| <div class="block">Join records of this stream with <a href="KTable.html" title="interface in org.apache.kafka.streams.kstream"><code>KTable</code></a>'s records using non-windowed inner equi join with default |
| serializers and deserializers. |
| The join is a primary key table lookup join with join attribute <code>stream.key == table.key</code>. |
| "Table lookup join" means, that results are only computed if <code>KStream</code> records are processed. |
| This is done by performing a lookup for matching records in the <em>current</em> (i.e., processing time) internal |
| <a href="KTable.html" title="interface in org.apache.kafka.streams.kstream"><code>KTable</code></a> state. |
| In contrast, processing <a href="KTable.html" title="interface in org.apache.kafka.streams.kstream"><code>KTable</code></a> input records will only update the internal <a href="KTable.html" title="interface in org.apache.kafka.streams.kstream"><code>KTable</code></a> state and |
| will not produce any result records. |
| <p> |
| For each <code>KStream</code> record that finds a corresponding record in <a href="KTable.html" title="interface in org.apache.kafka.streams.kstream"><code>KTable</code></a> the provided |
| <a href="ValueJoiner.html" title="interface in org.apache.kafka.streams.kstream"><code>ValueJoiner</code></a> will be called to compute a value (with arbitrary type) for the result record. |
| The key of the result record is the same as for both joining input records. |
| If an <code>KStream</code> input record key or value is <code>null</code> the record will not be included in the join |
| operation and thus no output record will be added to the resulting <code>KStream</code>. |
| <p> |
| Example: |
| <table border='1'> |
| <tr> |
| <th>KStream</th> |
| <th>KTable</th> |
| <th>state</th> |
| <th>result</th> |
| </tr> |
| <tr> |
| <td><K1:A></td> |
| <td></td> |
| <td></td> |
| <td></td> |
| </tr> |
| <tr> |
| <td></td> |
| <td><K1:b></td> |
| <td><K1:b></td> |
| <td></td> |
| </tr> |
| <tr> |
| <td><K1:C></td> |
| <td></td> |
| <td><K1:b></td> |
| <td><K1:ValueJoiner(C,b)></td> |
| </tr> |
| </table> |
| Both input streams (or to be more precise, their underlying source topics) need to have the same number of |
| partitions. |
| If this is not the case, you would need to call <a href="#repartition(org.apache.kafka.streams.kstream.Repartitioned)"><code>repartition(Repartitioned)</code></a> for this <code>KStream</code> |
| before doing the join, specifying the same number of partitions via <a href="Repartitioned.html" title="class in org.apache.kafka.streams.kstream"><code>Repartitioned</code></a> parameter as the given |
| <a href="KTable.html" title="interface in org.apache.kafka.streams.kstream"><code>KTable</code></a>. |
| Furthermore, both input streams need to be co-partitioned on the join key (i.e., use the same partitioner); |
| cf. <a href="#join(org.apache.kafka.streams.kstream.GlobalKTable,org.apache.kafka.streams.kstream.KeyValueMapper,org.apache.kafka.streams.kstream.ValueJoiner)"><code>join(GlobalKTable, KeyValueMapper, ValueJoiner)</code></a>. |
| If this requirement is not met, Kafka Streams will automatically repartition the data, i.e., it will create an |
| internal repartitioning topic in Kafka and write and re-read the data via this topic before the actual join. |
| The repartitioning topic will be named "${applicationId}-<name>-repartition", where "applicationId" is |
| user-specified in <a href="../StreamsConfig.html" title="class in org.apache.kafka.streams"><code>StreamsConfig</code></a> via parameter |
| <a href="../StreamsConfig.html#APPLICATION_ID_CONFIG"><code>APPLICATION_ID_CONFIG</code></a>, "<name>" is an internally generated |
| name, and "-repartition" is a fixed suffix. |
| <p> |
| You can retrieve all generated internal topic names via <a href="../Topology.html#describe()"><code>Topology.describe()</code></a>. |
| <p> |
| Repartitioning can happen only for this <code>KStream</code> but not for the provided <a href="KTable.html" title="interface in org.apache.kafka.streams.kstream"><code>KTable</code></a>. |
| For this case, all data of the stream will be redistributed through the repartitioning topic by writing all |
| records to it, and rereading all records from it, such that the join input <code>KStream</code> is partitioned |
| correctly on its key.</div> |
| <dl class="notes"> |
| <dt>Type Parameters:</dt> |
| <dd><code>VT</code> - the value type of the table</dd> |
| <dd><code>VR</code> - the value type of the result stream</dd> |
| <dt>Parameters:</dt> |
| <dd><code>table</code> - the <a href="KTable.html" title="interface in org.apache.kafka.streams.kstream"><code>KTable</code></a> to be joined with this stream</dd> |
| <dd><code>joiner</code> - a <a href="ValueJoiner.html" title="interface in org.apache.kafka.streams.kstream"><code>ValueJoiner</code></a> that computes the join result for a pair of matching records</dd> |
| <dd><code>joined</code> - a <a href="Joined.html" title="class in org.apache.kafka.streams.kstream"><code>Joined</code></a> instance that defines the serdes to |
| be used to serialize/deserialize inputs of the joined streams</dd> |
| <dt>Returns:</dt> |
| <dd>a <code>KStream</code> that contains join-records for each key and values computed by the given |
| <a href="ValueJoiner.html" title="interface in org.apache.kafka.streams.kstream"><code>ValueJoiner</code></a>, one for each matched record-pair with the same key</dd> |
| <dt>See Also:</dt> |
| <dd> |
| <ul class="see-list-long"> |
| <li><a href="#leftJoin(org.apache.kafka.streams.kstream.KTable,org.apache.kafka.streams.kstream.ValueJoiner,org.apache.kafka.streams.kstream.Joined)"><code>leftJoin(KTable, ValueJoiner, Joined)</code></a></li> |
| <li><a href="#join(org.apache.kafka.streams.kstream.GlobalKTable,org.apache.kafka.streams.kstream.KeyValueMapper,org.apache.kafka.streams.kstream.ValueJoiner)"><code>join(GlobalKTable, KeyValueMapper, ValueJoiner)</code></a></li> |
| </ul> |
| </dd> |
| </dl> |
| </section> |
| </li> |
| <li> |
| <section class="detail" id="join(org.apache.kafka.streams.kstream.KTable,org.apache.kafka.streams.kstream.ValueJoinerWithKey,org.apache.kafka.streams.kstream.Joined)"> |
| <h3>join</h3> |
| <div class="member-signature"><span class="type-parameters"><VT,<wbr> |
| VR></span> <span class="return-type"><a href="KStream.html" title="interface in org.apache.kafka.streams.kstream">KStream</a><<a href="KStream.html" title="type parameter in KStream">K</a>,<wbr>VR></span> <span class="element-name">join</span><wbr><span class="parameters">(<a href="KTable.html" title="interface in org.apache.kafka.streams.kstream">KTable</a><<a href="KStream.html" title="type parameter in KStream">K</a>,<wbr>VT> table, |
| <a href="ValueJoinerWithKey.html" title="interface in org.apache.kafka.streams.kstream">ValueJoinerWithKey</a><? super <a href="KStream.html" title="type parameter in KStream">K</a>,<wbr>? super <a href="KStream.html" title="type parameter in KStream">V</a>,<wbr>? super VT,<wbr>? extends VR> joiner, |
| <a href="Joined.html" title="class in org.apache.kafka.streams.kstream">Joined</a><<a href="KStream.html" title="type parameter in KStream">K</a>,<wbr><a href="KStream.html" title="type parameter in KStream">V</a>,<wbr>VT> joined)</span></div> |
| <div class="block">Join records of this stream with <a href="KTable.html" title="interface in org.apache.kafka.streams.kstream"><code>KTable</code></a>'s records using non-windowed inner equi join with default |
| serializers and deserializers. |
| The join is a primary key table lookup join with join attribute <code>stream.key == table.key</code>. |
| "Table lookup join" means, that results are only computed if <code>KStream</code> records are processed. |
| This is done by performing a lookup for matching records in the <em>current</em> (i.e., processing time) internal |
| <a href="KTable.html" title="interface in org.apache.kafka.streams.kstream"><code>KTable</code></a> state. |
| In contrast, processing <a href="KTable.html" title="interface in org.apache.kafka.streams.kstream"><code>KTable</code></a> input records will only update the internal <a href="KTable.html" title="interface in org.apache.kafka.streams.kstream"><code>KTable</code></a> state and |
| will not produce any result records. |
| <p> |
| For each <code>KStream</code> record that finds a corresponding record in <a href="KTable.html" title="interface in org.apache.kafka.streams.kstream"><code>KTable</code></a> the provided |
| <a href="ValueJoinerWithKey.html" title="interface in org.apache.kafka.streams.kstream"><code>ValueJoinerWithKey</code></a> will be called to compute a value (with arbitrary type) for the result record. |
| The key of the result record is the same as for both joining input records. |
| Note that the key is read-only and should not be modified, as this can lead to undefined behaviour. |
| |
| If an <code>KStream</code> input record key or value is <code>null</code> the record will not be included in the join |
| operation and thus no output record will be added to the resulting <code>KStream</code>. |
| <p> |
| Example: |
| <table border='1'> |
| <tr> |
| <th>KStream</th> |
| <th>KTable</th> |
| <th>state</th> |
| <th>result</th> |
| </tr> |
| <tr> |
| <td><K1:A></td> |
| <td></td> |
| <td></td> |
| <td></td> |
| </tr> |
| <tr> |
| <td></td> |
| <td><K1:b></td> |
| <td><K1:b></td> |
| <td></td> |
| </tr> |
| <tr> |
| <td><K1:C></td> |
| <td></td> |
| <td><K1:b></td> |
| <td><K1:ValueJoinerWithKey(K1,C,b)></td> |
| </tr> |
| </table> |
| Both input streams (or to be more precise, their underlying source topics) need to have the same number of |
| partitions. |
| If this is not the case, you would need to call <a href="#repartition(org.apache.kafka.streams.kstream.Repartitioned)"><code>repartition(Repartitioned)</code></a> for this <code>KStream</code> |
| before doing the join, specifying the same number of partitions via <a href="Repartitioned.html" title="class in org.apache.kafka.streams.kstream"><code>Repartitioned</code></a> parameter as the given |
| <a href="KTable.html" title="interface in org.apache.kafka.streams.kstream"><code>KTable</code></a>. |
| Furthermore, both input streams need to be co-partitioned on the join key (i.e., use the same partitioner); |
| cf. <a href="#join(org.apache.kafka.streams.kstream.GlobalKTable,org.apache.kafka.streams.kstream.KeyValueMapper,org.apache.kafka.streams.kstream.ValueJoinerWithKey)"><code>join(GlobalKTable, KeyValueMapper, ValueJoinerWithKey)</code></a>. |
| If this requirement is not met, Kafka Streams will automatically repartition the data, i.e., it will create an |
| internal repartitioning topic in Kafka and write and re-read the data via this topic before the actual join. |
| The repartitioning topic will be named "${applicationId}-<name>-repartition", where "applicationId" is |
| user-specified in <a href="../StreamsConfig.html" title="class in org.apache.kafka.streams"><code>StreamsConfig</code></a> via parameter |
| <a href="../StreamsConfig.html#APPLICATION_ID_CONFIG"><code>APPLICATION_ID_CONFIG</code></a>, "<name>" is an internally generated |
| name, and "-repartition" is a fixed suffix. |
| <p> |
| You can retrieve all generated internal topic names via <a href="../Topology.html#describe()"><code>Topology.describe()</code></a>. |
| <p> |
| Repartitioning can happen only for this <code>KStream</code> but not for the provided <a href="KTable.html" title="interface in org.apache.kafka.streams.kstream"><code>KTable</code></a>. |
| For this case, all data of the stream will be redistributed through the repartitioning topic by writing all |
| records to it, and rereading all records from it, such that the join input <code>KStream</code> is partitioned |
| correctly on its key.</div> |
| <dl class="notes"> |
| <dt>Type Parameters:</dt> |
| <dd><code>VT</code> - the value type of the table</dd> |
| <dd><code>VR</code> - the value type of the result stream</dd> |
| <dt>Parameters:</dt> |
| <dd><code>table</code> - the <a href="KTable.html" title="interface in org.apache.kafka.streams.kstream"><code>KTable</code></a> to be joined with this stream</dd> |
| <dd><code>joiner</code> - a <a href="ValueJoinerWithKey.html" title="interface in org.apache.kafka.streams.kstream"><code>ValueJoinerWithKey</code></a> that computes the join result for a pair of matching records</dd> |
| <dd><code>joined</code> - a <a href="Joined.html" title="class in org.apache.kafka.streams.kstream"><code>Joined</code></a> instance that defines the serdes to |
| be used to serialize/deserialize inputs of the joined streams</dd> |
| <dt>Returns:</dt> |
| <dd>a <code>KStream</code> that contains join-records for each key and values computed by the given |
| <a href="ValueJoinerWithKey.html" title="interface in org.apache.kafka.streams.kstream"><code>ValueJoinerWithKey</code></a>, one for each matched record-pair with the same key</dd> |
| <dt>See Also:</dt> |
| <dd> |
| <ul class="see-list-long"> |
| <li><a href="#leftJoin(org.apache.kafka.streams.kstream.KTable,org.apache.kafka.streams.kstream.ValueJoinerWithKey,org.apache.kafka.streams.kstream.Joined)"><code>leftJoin(KTable, ValueJoinerWithKey, Joined)</code></a></li> |
| <li><a href="#join(org.apache.kafka.streams.kstream.GlobalKTable,org.apache.kafka.streams.kstream.KeyValueMapper,org.apache.kafka.streams.kstream.ValueJoinerWithKey)"><code>join(GlobalKTable, KeyValueMapper, ValueJoinerWithKey)</code></a></li> |
| </ul> |
| </dd> |
| </dl> |
| </section> |
| </li> |
| <li> |
| <section class="detail" id="leftJoin(org.apache.kafka.streams.kstream.KTable,org.apache.kafka.streams.kstream.ValueJoiner)"> |
| <h3>leftJoin</h3> |
| <div class="member-signature"><span class="type-parameters"><VT,<wbr> |
| VR></span> <span class="return-type"><a href="KStream.html" title="interface in org.apache.kafka.streams.kstream">KStream</a><<a href="KStream.html" title="type parameter in KStream">K</a>,<wbr>VR></span> <span class="element-name">leftJoin</span><wbr><span class="parameters">(<a href="KTable.html" title="interface in org.apache.kafka.streams.kstream">KTable</a><<a href="KStream.html" title="type parameter in KStream">K</a>,<wbr>VT> table, |
| <a href="ValueJoiner.html" title="interface in org.apache.kafka.streams.kstream">ValueJoiner</a><? super <a href="KStream.html" title="type parameter in KStream">V</a>,<wbr>? super VT,<wbr>? extends VR> joiner)</span></div> |
| <div class="block">Join records of this stream with <a href="KTable.html" title="interface in org.apache.kafka.streams.kstream"><code>KTable</code></a>'s records using non-windowed left equi join with default |
| serializers and deserializers. |
| In contrast to <a href="#join(org.apache.kafka.streams.kstream.KTable,org.apache.kafka.streams.kstream.ValueJoiner)"><code>inner-join</code></a>, all records from this stream will produce an |
| output record (cf. below). |
| The join is a primary key table lookup join with join attribute <code>stream.key == table.key</code>. |
| "Table lookup join" means, that results are only computed if <code>KStream</code> records are processed. |
| This is done by performing a lookup for matching records in the <em>current</em> (i.e., processing time) internal |
| <a href="KTable.html" title="interface in org.apache.kafka.streams.kstream"><code>KTable</code></a> state. |
| In contrast, processing <a href="KTable.html" title="interface in org.apache.kafka.streams.kstream"><code>KTable</code></a> input records will only update the internal <a href="KTable.html" title="interface in org.apache.kafka.streams.kstream"><code>KTable</code></a> state and |
| will not produce any result records. |
| <p> |
| For each <code>KStream</code> record whether or not it finds a corresponding record in <a href="KTable.html" title="interface in org.apache.kafka.streams.kstream"><code>KTable</code></a> the provided |
| <a href="ValueJoiner.html" title="interface in org.apache.kafka.streams.kstream"><code>ValueJoiner</code></a> will be called to compute a value (with arbitrary type) for the result record. |
| If no <a href="KTable.html" title="interface in org.apache.kafka.streams.kstream"><code>KTable</code></a> record was found during lookup, a <code>null</code> value will be provided to <a href="ValueJoiner.html" title="interface in org.apache.kafka.streams.kstream"><code>ValueJoiner</code></a>. |
| The key of the result record is the same as for both joining input records. |
| If an <code>KStream</code> input record key or value is <code>null</code> the record will not be included in the join |
| operation and thus no output record will be added to the resulting <code>KStream</code>. |
| <p> |
| Example: |
| <table border='1'> |
| <tr> |
| <th>KStream</th> |
| <th>KTable</th> |
| <th>state</th> |
| <th>result</th> |
| </tr> |
| <tr> |
| <td><K1:A></td> |
| <td></td> |
| <td></td> |
| <td><K1:ValueJoiner(A,null)></td> |
| </tr> |
| <tr> |
| <td></td> |
| <td><K1:b></td> |
| <td><K1:b></td> |
| <td></td> |
| </tr> |
| <tr> |
| <td><K1:C></td> |
| <td></td> |
| <td><K1:b></td> |
| <td><K1:ValueJoiner(C,b)></td> |
| </tr> |
| </table> |
| Both input streams (or to be more precise, their underlying source topics) need to have the same number of |
| partitions. |
| If this is not the case, you would need to call <a href="#repartition(org.apache.kafka.streams.kstream.Repartitioned)"><code>repartition(Repartitioned)</code></a> for this <code>KStream</code> |
| before doing the join, specifying the same number of partitions via <a href="Repartitioned.html" title="class in org.apache.kafka.streams.kstream"><code>Repartitioned</code></a> parameter as the given |
| <a href="KTable.html" title="interface in org.apache.kafka.streams.kstream"><code>KTable</code></a>. |
| Furthermore, both input streams need to be co-partitioned on the join key (i.e., use the same partitioner); |
| cf. <a href="#join(org.apache.kafka.streams.kstream.GlobalKTable,org.apache.kafka.streams.kstream.KeyValueMapper,org.apache.kafka.streams.kstream.ValueJoiner)"><code>join(GlobalKTable, KeyValueMapper, ValueJoiner)</code></a>. |
| If this requirement is not met, Kafka Streams will automatically repartition the data, i.e., it will create an |
| internal repartitioning topic in Kafka and write and re-read the data via this topic before the actual join. |
| The repartitioning topic will be named "${applicationId}-<name>-repartition", where "applicationId" is |
| user-specified in <a href="../StreamsConfig.html" title="class in org.apache.kafka.streams"><code>StreamsConfig</code></a> via parameter |
| <a href="../StreamsConfig.html#APPLICATION_ID_CONFIG"><code>APPLICATION_ID_CONFIG</code></a>, "<name>" is an internally generated |
| name, and "-repartition" is a fixed suffix. |
| <p> |
| You can retrieve all generated internal topic names via <a href="../Topology.html#describe()"><code>Topology.describe()</code></a>. |
| <p> |
| Repartitioning can happen only for this <code>KStream</code> but not for the provided <a href="KTable.html" title="interface in org.apache.kafka.streams.kstream"><code>KTable</code></a>. |
| For this case, all data of the stream will be redistributed through the repartitioning topic by writing all |
| records to it, and rereading all records from it, such that the join input <code>KStream</code> is partitioned |
| correctly on its key.</div> |
| <dl class="notes"> |
| <dt>Type Parameters:</dt> |
| <dd><code>VT</code> - the value type of the table</dd> |
| <dd><code>VR</code> - the value type of the result stream</dd> |
| <dt>Parameters:</dt> |
| <dd><code>table</code> - the <a href="KTable.html" title="interface in org.apache.kafka.streams.kstream"><code>KTable</code></a> to be joined with this stream</dd> |
| <dd><code>joiner</code> - a <a href="ValueJoiner.html" title="interface in org.apache.kafka.streams.kstream"><code>ValueJoiner</code></a> that computes the join result for a pair of matching records</dd> |
| <dt>Returns:</dt> |
| <dd>a <code>KStream</code> that contains join-records for each key and values computed by the given |
| <a href="ValueJoiner.html" title="interface in org.apache.kafka.streams.kstream"><code>ValueJoiner</code></a>, one output for each input <code>KStream</code> record</dd> |
| <dt>See Also:</dt> |
| <dd> |
| <ul class="see-list-long"> |
| <li><a href="#join(org.apache.kafka.streams.kstream.KTable,org.apache.kafka.streams.kstream.ValueJoiner)"><code>join(KTable, ValueJoiner)</code></a></li> |
| <li><a href="#leftJoin(org.apache.kafka.streams.kstream.GlobalKTable,org.apache.kafka.streams.kstream.KeyValueMapper,org.apache.kafka.streams.kstream.ValueJoiner)"><code>leftJoin(GlobalKTable, KeyValueMapper, ValueJoiner)</code></a></li> |
| </ul> |
| </dd> |
| </dl> |
| </section> |
| </li> |
| <li> |
| <section class="detail" id="leftJoin(org.apache.kafka.streams.kstream.KTable,org.apache.kafka.streams.kstream.ValueJoinerWithKey)"> |
| <h3>leftJoin</h3> |
| <div class="member-signature"><span class="type-parameters"><VT,<wbr> |
| VR></span> <span class="return-type"><a href="KStream.html" title="interface in org.apache.kafka.streams.kstream">KStream</a><<a href="KStream.html" title="type parameter in KStream">K</a>,<wbr>VR></span> <span class="element-name">leftJoin</span><wbr><span class="parameters">(<a href="KTable.html" title="interface in org.apache.kafka.streams.kstream">KTable</a><<a href="KStream.html" title="type parameter in KStream">K</a>,<wbr>VT> table, |
| <a href="ValueJoinerWithKey.html" title="interface in org.apache.kafka.streams.kstream">ValueJoinerWithKey</a><? super <a href="KStream.html" title="type parameter in KStream">K</a>,<wbr>? super <a href="KStream.html" title="type parameter in KStream">V</a>,<wbr>? super VT,<wbr>? extends VR> joiner)</span></div> |
| <div class="block">Join records of this stream with <a href="KTable.html" title="interface in org.apache.kafka.streams.kstream"><code>KTable</code></a>'s records using non-windowed left equi join with default |
| serializers and deserializers. |
| In contrast to <a href="#join(org.apache.kafka.streams.kstream.KTable,org.apache.kafka.streams.kstream.ValueJoinerWithKey)"><code>inner-join</code></a>, all records from this stream will produce an |
| output record (cf. below). |
| The join is a primary key table lookup join with join attribute <code>stream.key == table.key</code>. |
| "Table lookup join" means, that results are only computed if <code>KStream</code> records are processed. |
| This is done by performing a lookup for matching records in the <em>current</em> (i.e., processing time) internal |
| <a href="KTable.html" title="interface in org.apache.kafka.streams.kstream"><code>KTable</code></a> state. |
| In contrast, processing <a href="KTable.html" title="interface in org.apache.kafka.streams.kstream"><code>KTable</code></a> input records will only update the internal <a href="KTable.html" title="interface in org.apache.kafka.streams.kstream"><code>KTable</code></a> state and |
| will not produce any result records. |
| <p> |
| For each <code>KStream</code> record whether or not it finds a corresponding record in <a href="KTable.html" title="interface in org.apache.kafka.streams.kstream"><code>KTable</code></a> the provided |
| <a href="ValueJoinerWithKey.html" title="interface in org.apache.kafka.streams.kstream"><code>ValueJoinerWithKey</code></a> will be called to compute a value (with arbitrary type) for the result record. |
| If no <a href="KTable.html" title="interface in org.apache.kafka.streams.kstream"><code>KTable</code></a> record was found during lookup, a <code>null</code> value will be provided to <a href="ValueJoinerWithKey.html" title="interface in org.apache.kafka.streams.kstream"><code>ValueJoinerWithKey</code></a>. |
| The key of the result record is the same as for both joining input records. |
| Note that the key is read-only and should not be modified, as this can lead to undefined behaviour. |
| If an <code>KStream</code> input record key or value is <code>null</code> the record will not be included in the join |
| operation and thus no output record will be added to the resulting <code>KStream</code>. |
| <p> |
| Example: |
| <table border='1'> |
| <tr> |
| <th>KStream</th> |
| <th>KTable</th> |
| <th>state</th> |
| <th>result</th> |
| </tr> |
| <tr> |
| <td><K1:A></td> |
| <td></td> |
| <td></td> |
| <td><K1:ValueJoinerWithKey(K1,A,null)></td> |
| </tr> |
| <tr> |
| <td></td> |
| <td><K1:b></td> |
| <td><K1:b></td> |
| <td></td> |
| </tr> |
| <tr> |
| <td><K1:C></td> |
| <td></td> |
| <td><K1:b></td> |
| <td><K1:ValueJoinerWithKey(K1,C,b)></td> |
| </tr> |
| </table> |
| Both input streams (or to be more precise, their underlying source topics) need to have the same number of |
| partitions. |
| If this is not the case, you would need to call <a href="#repartition(org.apache.kafka.streams.kstream.Repartitioned)"><code>repartition(Repartitioned)</code></a> for this <code>KStream</code> |
| before doing the join, specifying the same number of partitions via <a href="Repartitioned.html" title="class in org.apache.kafka.streams.kstream"><code>Repartitioned</code></a> parameter as the given |
| <a href="KTable.html" title="interface in org.apache.kafka.streams.kstream"><code>KTable</code></a>. |
| Furthermore, both input streams need to be co-partitioned on the join key (i.e., use the same partitioner); |
| cf. <a href="#join(org.apache.kafka.streams.kstream.GlobalKTable,org.apache.kafka.streams.kstream.KeyValueMapper,org.apache.kafka.streams.kstream.ValueJoinerWithKey)"><code>join(GlobalKTable, KeyValueMapper, ValueJoinerWithKey)</code></a>. |
| If this requirement is not met, Kafka Streams will automatically repartition the data, i.e., it will create an |
| internal repartitioning topic in Kafka and write and re-read the data via this topic before the actual join. |
| The repartitioning topic will be named "${applicationId}-<name>-repartition", where "applicationId" is |
| user-specified in <a href="../StreamsConfig.html" title="class in org.apache.kafka.streams"><code>StreamsConfig</code></a> via parameter |
| <a href="../StreamsConfig.html#APPLICATION_ID_CONFIG"><code>APPLICATION_ID_CONFIG</code></a>, "<name>" is an internally generated |
| name, and "-repartition" is a fixed suffix. |
| <p> |
| You can retrieve all generated internal topic names via <a href="../Topology.html#describe()"><code>Topology.describe()</code></a>. |
| <p> |
| Repartitioning can happen only for this <code>KStream</code> but not for the provided <a href="KTable.html" title="interface in org.apache.kafka.streams.kstream"><code>KTable</code></a>. |
| For this case, all data of the stream will be redistributed through the repartitioning topic by writing all |
| records to it, and rereading all records from it, such that the join input <code>KStream</code> is partitioned |
| correctly on its key.</div> |
| <dl class="notes"> |
| <dt>Type Parameters:</dt> |
| <dd><code>VT</code> - the value type of the table</dd> |
| <dd><code>VR</code> - the value type of the result stream</dd> |
| <dt>Parameters:</dt> |
| <dd><code>table</code> - the <a href="KTable.html" title="interface in org.apache.kafka.streams.kstream"><code>KTable</code></a> to be joined with this stream</dd> |
| <dd><code>joiner</code> - a <a href="ValueJoinerWithKey.html" title="interface in org.apache.kafka.streams.kstream"><code>ValueJoinerWithKey</code></a> that computes the join result for a pair of matching records</dd> |
| <dt>Returns:</dt> |
| <dd>a <code>KStream</code> that contains join-records for each key and values computed by the given |
| <a href="ValueJoinerWithKey.html" title="interface in org.apache.kafka.streams.kstream"><code>ValueJoinerWithKey</code></a>, one output for each input <code>KStream</code> record</dd> |
| <dt>See Also:</dt> |
| <dd> |
| <ul class="see-list-long"> |
| <li><a href="#join(org.apache.kafka.streams.kstream.KTable,org.apache.kafka.streams.kstream.ValueJoinerWithKey)"><code>join(KTable, ValueJoinerWithKey)</code></a></li> |
| <li><a href="#leftJoin(org.apache.kafka.streams.kstream.GlobalKTable,org.apache.kafka.streams.kstream.KeyValueMapper,org.apache.kafka.streams.kstream.ValueJoinerWithKey)"><code>leftJoin(GlobalKTable, KeyValueMapper, ValueJoinerWithKey)</code></a></li> |
| </ul> |
| </dd> |
| </dl> |
| </section> |
| </li> |
| <li> |
| <section class="detail" id="leftJoin(org.apache.kafka.streams.kstream.KTable,org.apache.kafka.streams.kstream.ValueJoiner,org.apache.kafka.streams.kstream.Joined)"> |
| <h3>leftJoin</h3> |
| <div class="member-signature"><span class="type-parameters"><VT,<wbr> |
| VR></span> <span class="return-type"><a href="KStream.html" title="interface in org.apache.kafka.streams.kstream">KStream</a><<a href="KStream.html" title="type parameter in KStream">K</a>,<wbr>VR></span> <span class="element-name">leftJoin</span><wbr><span class="parameters">(<a href="KTable.html" title="interface in org.apache.kafka.streams.kstream">KTable</a><<a href="KStream.html" title="type parameter in KStream">K</a>,<wbr>VT> table, |
| <a href="ValueJoiner.html" title="interface in org.apache.kafka.streams.kstream">ValueJoiner</a><? super <a href="KStream.html" title="type parameter in KStream">V</a>,<wbr>? super VT,<wbr>? extends VR> joiner, |
| <a href="Joined.html" title="class in org.apache.kafka.streams.kstream">Joined</a><<a href="KStream.html" title="type parameter in KStream">K</a>,<wbr><a href="KStream.html" title="type parameter in KStream">V</a>,<wbr>VT> joined)</span></div> |
| <div class="block">Join records of this stream with <a href="KTable.html" title="interface in org.apache.kafka.streams.kstream"><code>KTable</code></a>'s records using non-windowed left equi join with default |
| serializers and deserializers. |
| In contrast to <a href="#join(org.apache.kafka.streams.kstream.KTable,org.apache.kafka.streams.kstream.ValueJoiner)"><code>inner-join</code></a>, all records from this stream will produce an |
| output record (cf. below). |
| The join is a primary key table lookup join with join attribute <code>stream.key == table.key</code>. |
| "Table lookup join" means, that results are only computed if <code>KStream</code> records are processed. |
| This is done by performing a lookup for matching records in the <em>current</em> (i.e., processing time) internal |
| <a href="KTable.html" title="interface in org.apache.kafka.streams.kstream"><code>KTable</code></a> state. |
| In contrast, processing <a href="KTable.html" title="interface in org.apache.kafka.streams.kstream"><code>KTable</code></a> input records will only update the internal <a href="KTable.html" title="interface in org.apache.kafka.streams.kstream"><code>KTable</code></a> state and |
| will not produce any result records. |
| <p> |
| For each <code>KStream</code> record whether or not it finds a corresponding record in <a href="KTable.html" title="interface in org.apache.kafka.streams.kstream"><code>KTable</code></a> the provided |
| <a href="ValueJoiner.html" title="interface in org.apache.kafka.streams.kstream"><code>ValueJoiner</code></a> will be called to compute a value (with arbitrary type) for the result record. |
| If no <a href="KTable.html" title="interface in org.apache.kafka.streams.kstream"><code>KTable</code></a> record was found during lookup, a <code>null</code> value will be provided to <a href="ValueJoiner.html" title="interface in org.apache.kafka.streams.kstream"><code>ValueJoiner</code></a>. |
| The key of the result record is the same as for both joining input records. |
| If an <code>KStream</code> input record key or value is <code>null</code> the record will not be included in the join |
| operation and thus no output record will be added to the resulting <code>KStream</code>. |
| <p> |
| Example: |
| <table border='1'> |
| <tr> |
| <th>KStream</th> |
| <th>KTable</th> |
| <th>state</th> |
| <th>result</th> |
| </tr> |
| <tr> |
| <td><K1:A></td> |
| <td></td> |
| <td></td> |
| <td><K1:ValueJoiner(A,null)></td> |
| </tr> |
| <tr> |
| <td></td> |
| <td><K1:b></td> |
| <td><K1:b></td> |
| <td></td> |
| </tr> |
| <tr> |
| <td><K1:C></td> |
| <td></td> |
| <td><K1:b></td> |
| <td><K1:ValueJoiner(C,b)></td> |
| </tr> |
| </table> |
| Both input streams (or to be more precise, their underlying source topics) need to have the same number of |
| partitions. |
| If this is not the case, you would need to call <a href="#repartition(org.apache.kafka.streams.kstream.Repartitioned)"><code>repartition(Repartitioned)</code></a> for this <code>KStream</code> |
| before doing the join, specifying the same number of partitions via <a href="Repartitioned.html" title="class in org.apache.kafka.streams.kstream"><code>Repartitioned</code></a> parameter as the given |
| <a href="KTable.html" title="interface in org.apache.kafka.streams.kstream"><code>KTable</code></a>. |
| Furthermore, both input streams need to be co-partitioned on the join key (i.e., use the same partitioner); |
| cf. <a href="#join(org.apache.kafka.streams.kstream.GlobalKTable,org.apache.kafka.streams.kstream.KeyValueMapper,org.apache.kafka.streams.kstream.ValueJoiner)"><code>join(GlobalKTable, KeyValueMapper, ValueJoiner)</code></a>. |
| If this requirement is not met, Kafka Streams will automatically repartition the data, i.e., it will create an |
| internal repartitioning topic in Kafka and write and re-read the data via this topic before the actual join. |
| The repartitioning topic will be named "${applicationId}-<name>-repartition", where "applicationId" is |
| user-specified in <a href="../StreamsConfig.html" title="class in org.apache.kafka.streams"><code>StreamsConfig</code></a> via parameter |
| <a href="../StreamsConfig.html#APPLICATION_ID_CONFIG"><code>APPLICATION_ID_CONFIG</code></a>, "<name>" is an internally generated |
| name, and "-repartition" is a fixed suffix. |
| <p> |
| You can retrieve all generated internal topic names via <a href="../Topology.html#describe()"><code>Topology.describe()</code></a>. |
| <p> |
| Repartitioning can happen only for this <code>KStream</code> but not for the provided <a href="KTable.html" title="interface in org.apache.kafka.streams.kstream"><code>KTable</code></a>. |
| For this case, all data of the stream will be redistributed through the repartitioning topic by writing all |
| records to it, and rereading all records from it, such that the join input <code>KStream</code> is partitioned |
| correctly on its key.</div> |
| <dl class="notes"> |
| <dt>Type Parameters:</dt> |
| <dd><code>VT</code> - the value type of the table</dd> |
| <dd><code>VR</code> - the value type of the result stream</dd> |
| <dt>Parameters:</dt> |
| <dd><code>table</code> - the <a href="KTable.html" title="interface in org.apache.kafka.streams.kstream"><code>KTable</code></a> to be joined with this stream</dd> |
| <dd><code>joiner</code> - a <a href="ValueJoiner.html" title="interface in org.apache.kafka.streams.kstream"><code>ValueJoiner</code></a> that computes the join result for a pair of matching records</dd> |
| <dd><code>joined</code> - a <a href="Joined.html" title="class in org.apache.kafka.streams.kstream"><code>Joined</code></a> instance that defines the serdes to |
| be used to serialize/deserialize inputs and outputs of the joined streams</dd> |
| <dt>Returns:</dt> |
| <dd>a <code>KStream</code> that contains join-records for each key and values computed by the given |
| <a href="ValueJoiner.html" title="interface in org.apache.kafka.streams.kstream"><code>ValueJoiner</code></a>, one output for each input <code>KStream</code> record</dd> |
| <dt>See Also:</dt> |
| <dd> |
| <ul class="see-list-long"> |
| <li><a href="#join(org.apache.kafka.streams.kstream.KTable,org.apache.kafka.streams.kstream.ValueJoiner,org.apache.kafka.streams.kstream.Joined)"><code>join(KTable, ValueJoiner, Joined)</code></a></li> |
| <li><a href="#leftJoin(org.apache.kafka.streams.kstream.GlobalKTable,org.apache.kafka.streams.kstream.KeyValueMapper,org.apache.kafka.streams.kstream.ValueJoiner)"><code>leftJoin(GlobalKTable, KeyValueMapper, ValueJoiner)</code></a></li> |
| </ul> |
| </dd> |
| </dl> |
| </section> |
| </li> |
| <li> |
| <section class="detail" id="leftJoin(org.apache.kafka.streams.kstream.KTable,org.apache.kafka.streams.kstream.ValueJoinerWithKey,org.apache.kafka.streams.kstream.Joined)"> |
| <h3>leftJoin</h3> |
| <div class="member-signature"><span class="type-parameters"><VT,<wbr> |
| VR></span> <span class="return-type"><a href="KStream.html" title="interface in org.apache.kafka.streams.kstream">KStream</a><<a href="KStream.html" title="type parameter in KStream">K</a>,<wbr>VR></span> <span class="element-name">leftJoin</span><wbr><span class="parameters">(<a href="KTable.html" title="interface in org.apache.kafka.streams.kstream">KTable</a><<a href="KStream.html" title="type parameter in KStream">K</a>,<wbr>VT> table, |
| <a href="ValueJoinerWithKey.html" title="interface in org.apache.kafka.streams.kstream">ValueJoinerWithKey</a><? super <a href="KStream.html" title="type parameter in KStream">K</a>,<wbr>? super <a href="KStream.html" title="type parameter in KStream">V</a>,<wbr>? super VT,<wbr>? extends VR> joiner, |
| <a href="Joined.html" title="class in org.apache.kafka.streams.kstream">Joined</a><<a href="KStream.html" title="type parameter in KStream">K</a>,<wbr><a href="KStream.html" title="type parameter in KStream">V</a>,<wbr>VT> joined)</span></div> |
| <div class="block">Join records of this stream with <a href="KTable.html" title="interface in org.apache.kafka.streams.kstream"><code>KTable</code></a>'s records using non-windowed left equi join with default |
| serializers and deserializers. |
| In contrast to <a href="#join(org.apache.kafka.streams.kstream.KTable,org.apache.kafka.streams.kstream.ValueJoinerWithKey)"><code>inner-join</code></a>, all records from this stream will produce an |
| output record (cf. below). |
| The join is a primary key table lookup join with join attribute <code>stream.key == table.key</code>. |
| "Table lookup join" means, that results are only computed if <code>KStream</code> records are processed. |
| This is done by performing a lookup for matching records in the <em>current</em> (i.e., processing time) internal |
| <a href="KTable.html" title="interface in org.apache.kafka.streams.kstream"><code>KTable</code></a> state. |
| In contrast, processing <a href="KTable.html" title="interface in org.apache.kafka.streams.kstream"><code>KTable</code></a> input records will only update the internal <a href="KTable.html" title="interface in org.apache.kafka.streams.kstream"><code>KTable</code></a> state and |
| will not produce any result records. |
| <p> |
| For each <code>KStream</code> record whether or not it finds a corresponding record in <a href="KTable.html" title="interface in org.apache.kafka.streams.kstream"><code>KTable</code></a> the provided |
| <a href="ValueJoinerWithKey.html" title="interface in org.apache.kafka.streams.kstream"><code>ValueJoinerWithKey</code></a> will be called to compute a value (with arbitrary type) for the result record. |
| If no <a href="KTable.html" title="interface in org.apache.kafka.streams.kstream"><code>KTable</code></a> record was found during lookup, a <code>null</code> value will be provided to <a href="ValueJoinerWithKey.html" title="interface in org.apache.kafka.streams.kstream"><code>ValueJoinerWithKey</code></a>. |
| The key of the result record is the same as for both joining input records. |
| Note that the key is read-only and should not be modified, as this can lead to undefined behaviour. |
| If an <code>KStream</code> input record key or value is <code>null</code> the record will not be included in the join |
| operation and thus no output record will be added to the resulting <code>KStream</code>. |
| <p> |
| Example: |
| <table border='1'> |
| <tr> |
| <th>KStream</th> |
| <th>KTable</th> |
| <th>state</th> |
| <th>result</th> |
| </tr> |
| <tr> |
| <td><K1:A></td> |
| <td></td> |
| <td></td> |
| <td><K1:ValueJoinerWithKey(K1,A,null)></td> |
| </tr> |
| <tr> |
| <td></td> |
| <td><K1:b></td> |
| <td><K1:b></td> |
| <td></td> |
| </tr> |
| <tr> |
| <td><K1:C></td> |
| <td></td> |
| <td><K1:b></td> |
| <td><K1:ValueJoinerWithKey(K1,C,b)></td> |
| </tr> |
| </table> |
| Both input streams (or to be more precise, their underlying source topics) need to have the same number of |
| partitions. |
| If this is not the case, you would need to call <a href="#repartition(org.apache.kafka.streams.kstream.Repartitioned)"><code>repartition(Repartitioned)</code></a> for this <code>KStream</code> |
| before doing the join, specifying the same number of partitions via <a href="Repartitioned.html" title="class in org.apache.kafka.streams.kstream"><code>Repartitioned</code></a> parameter as the given |
| <a href="KTable.html" title="interface in org.apache.kafka.streams.kstream"><code>KTable</code></a>. |
| Furthermore, both input streams need to be co-partitioned on the join key (i.e., use the same partitioner); |
| cf. <a href="#join(org.apache.kafka.streams.kstream.GlobalKTable,org.apache.kafka.streams.kstream.KeyValueMapper,org.apache.kafka.streams.kstream.ValueJoinerWithKey)"><code>join(GlobalKTable, KeyValueMapper, ValueJoinerWithKey)</code></a>. |
| If this requirement is not met, Kafka Streams will automatically repartition the data, i.e., it will create an |
| internal repartitioning topic in Kafka and write and re-read the data via this topic before the actual join. |
| The repartitioning topic will be named "${applicationId}-<name>-repartition", where "applicationId" is |
| user-specified in <a href="../StreamsConfig.html" title="class in org.apache.kafka.streams"><code>StreamsConfig</code></a> via parameter |
| <a href="../StreamsConfig.html#APPLICATION_ID_CONFIG"><code>APPLICATION_ID_CONFIG</code></a>, "<name>" is an internally generated |
| name, and "-repartition" is a fixed suffix. |
| <p> |
| You can retrieve all generated internal topic names via <a href="../Topology.html#describe()"><code>Topology.describe()</code></a>. |
| <p> |
| Repartitioning can happen only for this <code>KStream</code> but not for the provided <a href="KTable.html" title="interface in org.apache.kafka.streams.kstream"><code>KTable</code></a>. |
| For this case, all data of the stream will be redistributed through the repartitioning topic by writing all |
| records to it, and rereading all records from it, such that the join input <code>KStream</code> is partitioned |
| correctly on its key.</div> |
| <dl class="notes"> |
| <dt>Type Parameters:</dt> |
| <dd><code>VT</code> - the value type of the table</dd> |
| <dd><code>VR</code> - the value type of the result stream</dd> |
| <dt>Parameters:</dt> |
| <dd><code>table</code> - the <a href="KTable.html" title="interface in org.apache.kafka.streams.kstream"><code>KTable</code></a> to be joined with this stream</dd> |
| <dd><code>joiner</code> - a <a href="ValueJoinerWithKey.html" title="interface in org.apache.kafka.streams.kstream"><code>ValueJoinerWithKey</code></a> that computes the join result for a pair of matching records</dd> |
| <dd><code>joined</code> - a <a href="Joined.html" title="class in org.apache.kafka.streams.kstream"><code>Joined</code></a> instance that defines the serdes to |
| be used to serialize/deserialize inputs and outputs of the joined streams</dd> |
| <dt>Returns:</dt> |
| <dd>a <code>KStream</code> that contains join-records for each key and values computed by the given |
| <a href="ValueJoinerWithKey.html" title="interface in org.apache.kafka.streams.kstream"><code>ValueJoinerWithKey</code></a>, one output for each input <code>KStream</code> record</dd> |
| <dt>See Also:</dt> |
| <dd> |
| <ul class="see-list-long"> |
| <li><a href="#join(org.apache.kafka.streams.kstream.KTable,org.apache.kafka.streams.kstream.ValueJoinerWithKey,org.apache.kafka.streams.kstream.Joined)"><code>join(KTable, ValueJoinerWithKey, Joined)</code></a></li> |
| <li><a href="#leftJoin(org.apache.kafka.streams.kstream.GlobalKTable,org.apache.kafka.streams.kstream.KeyValueMapper,org.apache.kafka.streams.kstream.ValueJoinerWithKey)"><code>leftJoin(GlobalKTable, KeyValueMapper, ValueJoinerWithKey)</code></a></li> |
| </ul> |
| </dd> |
| </dl> |
| </section> |
| </li> |
| <li> |
| <section class="detail" id="join(org.apache.kafka.streams.kstream.GlobalKTable,org.apache.kafka.streams.kstream.KeyValueMapper,org.apache.kafka.streams.kstream.ValueJoiner)"> |
| <h3>join</h3> |
| <div class="member-signature"><span class="type-parameters"><GK,<wbr> |
| GV,<wbr> |
| RV></span> <span class="return-type"><a href="KStream.html" title="interface in org.apache.kafka.streams.kstream">KStream</a><<a href="KStream.html" title="type parameter in KStream">K</a>,<wbr>RV></span> <span class="element-name">join</span><wbr><span class="parameters">(<a href="GlobalKTable.html" title="interface in org.apache.kafka.streams.kstream">GlobalKTable</a><GK,<wbr>GV> globalTable, |
| <a href="KeyValueMapper.html" title="interface in org.apache.kafka.streams.kstream">KeyValueMapper</a><? super <a href="KStream.html" title="type parameter in KStream">K</a>,<wbr>? super <a href="KStream.html" title="type parameter in KStream">V</a>,<wbr>? extends GK> keySelector, |
| <a href="ValueJoiner.html" title="interface in org.apache.kafka.streams.kstream">ValueJoiner</a><? super <a href="KStream.html" title="type parameter in KStream">V</a>,<wbr>? super GV,<wbr>? extends RV> joiner)</span></div> |
| <div class="block">Join records of this stream with <a href="GlobalKTable.html" title="interface in org.apache.kafka.streams.kstream"><code>GlobalKTable</code></a>'s records using non-windowed inner equi join. |
| The join is a primary key table lookup join with join attribute |
| <code>keyValueMapper.map(stream.keyValue) == table.key</code>. |
| "Table lookup join" means, that results are only computed if <code>KStream</code> records are processed. |
| This is done by performing a lookup for matching records in the <em>current</em> internal <a href="GlobalKTable.html" title="interface in org.apache.kafka.streams.kstream"><code>GlobalKTable</code></a> |
| state. |
| In contrast, processing <a href="GlobalKTable.html" title="interface in org.apache.kafka.streams.kstream"><code>GlobalKTable</code></a> input records will only update the internal <a href="GlobalKTable.html" title="interface in org.apache.kafka.streams.kstream"><code>GlobalKTable</code></a> |
| state and will not produce any result records. |
| <p> |
| For each <code>KStream</code> record that finds a corresponding record in <a href="GlobalKTable.html" title="interface in org.apache.kafka.streams.kstream"><code>GlobalKTable</code></a> the provided |
| <a href="ValueJoiner.html" title="interface in org.apache.kafka.streams.kstream"><code>ValueJoiner</code></a> will be called to compute a value (with arbitrary type) for the result record. |
| The key of the result record is the same as the key of this <code>KStream</code>. |
| If a <code>KStream</code> input record key or value is <code>null</code> the record will not be included in the join |
| operation and thus no output record will be added to the resulting <code>KStream</code>. |
| If <code>keyValueMapper</code> returns <code>null</code> implying no match exists, no output record will be added to the |
| resulting <code>KStream</code>.</div> |
| <dl class="notes"> |
| <dt>Type Parameters:</dt> |
| <dd><code>GK</code> - the key type of <a href="GlobalKTable.html" title="interface in org.apache.kafka.streams.kstream"><code>GlobalKTable</code></a></dd> |
| <dd><code>GV</code> - the value type of the <a href="GlobalKTable.html" title="interface in org.apache.kafka.streams.kstream"><code>GlobalKTable</code></a></dd> |
| <dd><code>RV</code> - the value type of the resulting <code>KStream</code></dd> |
| <dt>Parameters:</dt> |
| <dd><code>globalTable</code> - the <a href="GlobalKTable.html" title="interface in org.apache.kafka.streams.kstream"><code>GlobalKTable</code></a> to be joined with this stream</dd> |
| <dd><code>keySelector</code> - instance of <a href="KeyValueMapper.html" title="interface in org.apache.kafka.streams.kstream"><code>KeyValueMapper</code></a> used to map from the (key, value) of this stream |
| to the key of the <a href="GlobalKTable.html" title="interface in org.apache.kafka.streams.kstream"><code>GlobalKTable</code></a></dd> |
| <dd><code>joiner</code> - a <a href="ValueJoiner.html" title="interface in org.apache.kafka.streams.kstream"><code>ValueJoiner</code></a> that computes the join result for a pair of matching records</dd> |
| <dt>Returns:</dt> |
| <dd>a <code>KStream</code> that contains join-records for each key and values computed by the given |
| <a href="ValueJoiner.html" title="interface in org.apache.kafka.streams.kstream"><code>ValueJoiner</code></a>, one output for each input <code>KStream</code> record</dd> |
| <dt>See Also:</dt> |
| <dd> |
| <ul class="see-list-long"> |
| <li><a href="#leftJoin(org.apache.kafka.streams.kstream.GlobalKTable,org.apache.kafka.streams.kstream.KeyValueMapper,org.apache.kafka.streams.kstream.ValueJoiner)"><code>leftJoin(GlobalKTable, KeyValueMapper, ValueJoiner)</code></a></li> |
| </ul> |
| </dd> |
| </dl> |
| </section> |
| </li> |
| <li> |
| <section class="detail" id="join(org.apache.kafka.streams.kstream.GlobalKTable,org.apache.kafka.streams.kstream.KeyValueMapper,org.apache.kafka.streams.kstream.ValueJoinerWithKey)"> |
| <h3>join</h3> |
| <div class="member-signature"><span class="type-parameters"><GK,<wbr> |
| GV,<wbr> |
| RV></span> <span class="return-type"><a href="KStream.html" title="interface in org.apache.kafka.streams.kstream">KStream</a><<a href="KStream.html" title="type parameter in KStream">K</a>,<wbr>RV></span> <span class="element-name">join</span><wbr><span class="parameters">(<a href="GlobalKTable.html" title="interface in org.apache.kafka.streams.kstream">GlobalKTable</a><GK,<wbr>GV> globalTable, |
| <a href="KeyValueMapper.html" title="interface in org.apache.kafka.streams.kstream">KeyValueMapper</a><? super <a href="KStream.html" title="type parameter in KStream">K</a>,<wbr>? super <a href="KStream.html" title="type parameter in KStream">V</a>,<wbr>? extends GK> keySelector, |
| <a href="ValueJoinerWithKey.html" title="interface in org.apache.kafka.streams.kstream">ValueJoinerWithKey</a><? super <a href="KStream.html" title="type parameter in KStream">K</a>,<wbr>? super <a href="KStream.html" title="type parameter in KStream">V</a>,<wbr>? super GV,<wbr>? extends RV> joiner)</span></div> |
| <div class="block">Join records of this stream with <a href="GlobalKTable.html" title="interface in org.apache.kafka.streams.kstream"><code>GlobalKTable</code></a>'s records using non-windowed inner equi join. |
| The join is a primary key table lookup join with join attribute |
| <code>keyValueMapper.map(stream.keyValue) == table.key</code>. |
| "Table lookup join" means, that results are only computed if <code>KStream</code> records are processed. |
| This is done by performing a lookup for matching records in the <em>current</em> internal <a href="GlobalKTable.html" title="interface in org.apache.kafka.streams.kstream"><code>GlobalKTable</code></a> |
| state. |
| In contrast, processing <a href="GlobalKTable.html" title="interface in org.apache.kafka.streams.kstream"><code>GlobalKTable</code></a> input records will only update the internal <a href="GlobalKTable.html" title="interface in org.apache.kafka.streams.kstream"><code>GlobalKTable</code></a> |
| state and will not produce any result records. |
| <p> |
| For each <code>KStream</code> record that finds a corresponding record in <a href="GlobalKTable.html" title="interface in org.apache.kafka.streams.kstream"><code>GlobalKTable</code></a> the provided |
| <a href="ValueJoinerWithKey.html" title="interface in org.apache.kafka.streams.kstream"><code>ValueJoinerWithKey</code></a> will be called to compute a value (with arbitrary type) for the result record. |
| The key of the result record is the same as the key of this <code>KStream</code>. |
| Note that the key is read-only and should not be modified, as this can lead to undefined behaviour. |
| If a <code>KStream</code> input record key or value is <code>null</code> the record will not be included in the join |
| operation and thus no output record will be added to the resulting <code>KStream</code>. |
| If <code>keyValueMapper</code> returns <code>null</code> implying no match exists, no output record will be added to the |
| resulting <code>KStream</code>.</div> |
| <dl class="notes"> |
| <dt>Type Parameters:</dt> |
| <dd><code>GK</code> - the key type of <a href="GlobalKTable.html" title="interface in org.apache.kafka.streams.kstream"><code>GlobalKTable</code></a></dd> |
| <dd><code>GV</code> - the value type of the <a href="GlobalKTable.html" title="interface in org.apache.kafka.streams.kstream"><code>GlobalKTable</code></a></dd> |
| <dd><code>RV</code> - the value type of the resulting <code>KStream</code></dd> |
| <dt>Parameters:</dt> |
| <dd><code>globalTable</code> - the <a href="GlobalKTable.html" title="interface in org.apache.kafka.streams.kstream"><code>GlobalKTable</code></a> to be joined with this stream</dd> |
| <dd><code>keySelector</code> - instance of <a href="KeyValueMapper.html" title="interface in org.apache.kafka.streams.kstream"><code>KeyValueMapper</code></a> used to map from the (key, value) of this stream |
| to the key of the <a href="GlobalKTable.html" title="interface in org.apache.kafka.streams.kstream"><code>GlobalKTable</code></a></dd> |
| <dd><code>joiner</code> - a <a href="ValueJoinerWithKey.html" title="interface in org.apache.kafka.streams.kstream"><code>ValueJoinerWithKey</code></a> that computes the join result for a pair of matching records</dd> |
| <dt>Returns:</dt> |
| <dd>a <code>KStream</code> that contains join-records for each key and values computed by the given |
| <a href="ValueJoinerWithKey.html" title="interface in org.apache.kafka.streams.kstream"><code>ValueJoinerWithKey</code></a>, one output for each input <code>KStream</code> record</dd> |
| <dt>See Also:</dt> |
| <dd> |
| <ul class="see-list-long"> |
| <li><a href="#leftJoin(org.apache.kafka.streams.kstream.GlobalKTable,org.apache.kafka.streams.kstream.KeyValueMapper,org.apache.kafka.streams.kstream.ValueJoinerWithKey)"><code>leftJoin(GlobalKTable, KeyValueMapper, ValueJoinerWithKey)</code></a></li> |
| </ul> |
| </dd> |
| </dl> |
| </section> |
| </li> |
| <li> |
| <section class="detail" id="join(org.apache.kafka.streams.kstream.GlobalKTable,org.apache.kafka.streams.kstream.KeyValueMapper,org.apache.kafka.streams.kstream.ValueJoiner,org.apache.kafka.streams.kstream.Named)"> |
| <h3>join</h3> |
| <div class="member-signature"><span class="type-parameters"><GK,<wbr> |
| GV,<wbr> |
| RV></span> <span class="return-type"><a href="KStream.html" title="interface in org.apache.kafka.streams.kstream">KStream</a><<a href="KStream.html" title="type parameter in KStream">K</a>,<wbr>RV></span> <span class="element-name">join</span><wbr><span class="parameters">(<a href="GlobalKTable.html" title="interface in org.apache.kafka.streams.kstream">GlobalKTable</a><GK,<wbr>GV> globalTable, |
| <a href="KeyValueMapper.html" title="interface in org.apache.kafka.streams.kstream">KeyValueMapper</a><? super <a href="KStream.html" title="type parameter in KStream">K</a>,<wbr>? super <a href="KStream.html" title="type parameter in KStream">V</a>,<wbr>? extends GK> keySelector, |
| <a href="ValueJoiner.html" title="interface in org.apache.kafka.streams.kstream">ValueJoiner</a><? super <a href="KStream.html" title="type parameter in KStream">V</a>,<wbr>? super GV,<wbr>? extends RV> joiner, |
| <a href="Named.html" title="class in org.apache.kafka.streams.kstream">Named</a> named)</span></div> |
| <div class="block">Join records of this stream with <a href="GlobalKTable.html" title="interface in org.apache.kafka.streams.kstream"><code>GlobalKTable</code></a>'s records using non-windowed inner equi join. |
| The join is a primary key table lookup join with join attribute |
| <code>keyValueMapper.map(stream.keyValue) == table.key</code>. |
| "Table lookup join" means, that results are only computed if <code>KStream</code> records are processed. |
| This is done by performing a lookup for matching records in the <em>current</em> internal <a href="GlobalKTable.html" title="interface in org.apache.kafka.streams.kstream"><code>GlobalKTable</code></a> |
| state. |
| In contrast, processing <a href="GlobalKTable.html" title="interface in org.apache.kafka.streams.kstream"><code>GlobalKTable</code></a> input records will only update the internal <a href="GlobalKTable.html" title="interface in org.apache.kafka.streams.kstream"><code>GlobalKTable</code></a> |
| state and will not produce any result records. |
| <p> |
| For each <code>KStream</code> record that finds a corresponding record in <a href="GlobalKTable.html" title="interface in org.apache.kafka.streams.kstream"><code>GlobalKTable</code></a> the provided |
| <a href="ValueJoiner.html" title="interface in org.apache.kafka.streams.kstream"><code>ValueJoiner</code></a> will be called to compute a value (with arbitrary type) for the result record. |
| The key of the result record is the same as the key of this <code>KStream</code>. |
| If a <code>KStream</code> input record key or value is <code>null</code> the record will not be included in the join |
| operation and thus no output record will be added to the resulting <code>KStream</code>. |
| If <code>keyValueMapper</code> returns <code>null</code> implying no match exists, no output record will be added to the |
| resulting <code>KStream</code>.</div> |
| <dl class="notes"> |
| <dt>Type Parameters:</dt> |
| <dd><code>GK</code> - the key type of <a href="GlobalKTable.html" title="interface in org.apache.kafka.streams.kstream"><code>GlobalKTable</code></a></dd> |
| <dd><code>GV</code> - the value type of the <a href="GlobalKTable.html" title="interface in org.apache.kafka.streams.kstream"><code>GlobalKTable</code></a></dd> |
| <dd><code>RV</code> - the value type of the resulting <code>KStream</code></dd> |
| <dt>Parameters:</dt> |
| <dd><code>globalTable</code> - the <a href="GlobalKTable.html" title="interface in org.apache.kafka.streams.kstream"><code>GlobalKTable</code></a> to be joined with this stream</dd> |
| <dd><code>keySelector</code> - instance of <a href="KeyValueMapper.html" title="interface in org.apache.kafka.streams.kstream"><code>KeyValueMapper</code></a> used to map from the (key, value) of this stream |
| to the key of the <a href="GlobalKTable.html" title="interface in org.apache.kafka.streams.kstream"><code>GlobalKTable</code></a></dd> |
| <dd><code>joiner</code> - a <a href="ValueJoiner.html" title="interface in org.apache.kafka.streams.kstream"><code>ValueJoiner</code></a> that computes the join result for a pair of matching records</dd> |
| <dd><code>named</code> - a <a href="Named.html" title="class in org.apache.kafka.streams.kstream"><code>Named</code></a> config used to name the processor in the topology</dd> |
| <dt>Returns:</dt> |
| <dd>a <code>KStream</code> that contains join-records for each key and values computed by the given |
| <a href="ValueJoiner.html" title="interface in org.apache.kafka.streams.kstream"><code>ValueJoiner</code></a>, one output for each input <code>KStream</code> record</dd> |
| <dt>See Also:</dt> |
| <dd> |
| <ul class="see-list-long"> |
| <li><a href="#leftJoin(org.apache.kafka.streams.kstream.GlobalKTable,org.apache.kafka.streams.kstream.KeyValueMapper,org.apache.kafka.streams.kstream.ValueJoiner)"><code>leftJoin(GlobalKTable, KeyValueMapper, ValueJoiner)</code></a></li> |
| </ul> |
| </dd> |
| </dl> |
| </section> |
| </li> |
| <li> |
| <section class="detail" id="join(org.apache.kafka.streams.kstream.GlobalKTable,org.apache.kafka.streams.kstream.KeyValueMapper,org.apache.kafka.streams.kstream.ValueJoinerWithKey,org.apache.kafka.streams.kstream.Named)"> |
| <h3>join</h3> |
| <div class="member-signature"><span class="type-parameters"><GK,<wbr> |
| GV,<wbr> |
| RV></span> <span class="return-type"><a href="KStream.html" title="interface in org.apache.kafka.streams.kstream">KStream</a><<a href="KStream.html" title="type parameter in KStream">K</a>,<wbr>RV></span> <span class="element-name">join</span><wbr><span class="parameters">(<a href="GlobalKTable.html" title="interface in org.apache.kafka.streams.kstream">GlobalKTable</a><GK,<wbr>GV> globalTable, |
| <a href="KeyValueMapper.html" title="interface in org.apache.kafka.streams.kstream">KeyValueMapper</a><? super <a href="KStream.html" title="type parameter in KStream">K</a>,<wbr>? super <a href="KStream.html" title="type parameter in KStream">V</a>,<wbr>? extends GK> keySelector, |
| <a href="ValueJoinerWithKey.html" title="interface in org.apache.kafka.streams.kstream">ValueJoinerWithKey</a><? super <a href="KStream.html" title="type parameter in KStream">K</a>,<wbr>? super <a href="KStream.html" title="type parameter in KStream">V</a>,<wbr>? super GV,<wbr>? extends RV> joiner, |
| <a href="Named.html" title="class in org.apache.kafka.streams.kstream">Named</a> named)</span></div> |
| <div class="block">Join records of this stream with <a href="GlobalKTable.html" title="interface in org.apache.kafka.streams.kstream"><code>GlobalKTable</code></a>'s records using non-windowed inner equi join. |
| The join is a primary key table lookup join with join attribute |
| <code>keyValueMapper.map(stream.keyValue) == table.key</code>. |
| "Table lookup join" means, that results are only computed if <code>KStream</code> records are processed. |
| This is done by performing a lookup for matching records in the <em>current</em> internal <a href="GlobalKTable.html" title="interface in org.apache.kafka.streams.kstream"><code>GlobalKTable</code></a> |
| state. |
| In contrast, processing <a href="GlobalKTable.html" title="interface in org.apache.kafka.streams.kstream"><code>GlobalKTable</code></a> input records will only update the internal <a href="GlobalKTable.html" title="interface in org.apache.kafka.streams.kstream"><code>GlobalKTable</code></a> |
| state and will not produce any result records. |
| <p> |
| For each <code>KStream</code> record that finds a corresponding record in <a href="GlobalKTable.html" title="interface in org.apache.kafka.streams.kstream"><code>GlobalKTable</code></a> the provided |
| <a href="ValueJoinerWithKey.html" title="interface in org.apache.kafka.streams.kstream"><code>ValueJoinerWithKey</code></a> will be called to compute a value (with arbitrary type) for the result record. |
| The key of the result record is the same as the key of this <code>KStream</code>. |
| Note that the key is read-only and should not be modified, as this can lead to undefined behaviour. |
| If a <code>KStream</code> input record key or value is <code>null</code> the record will not be included in the join |
| operation and thus no output record will be added to the resulting <code>KStream</code>. |
| If <code>keyValueMapper</code> returns <code>null</code> implying no match exists, no output record will be added to the |
| resulting <code>KStream</code>.</div> |
| <dl class="notes"> |
| <dt>Type Parameters:</dt> |
| <dd><code>GK</code> - the key type of <a href="GlobalKTable.html" title="interface in org.apache.kafka.streams.kstream"><code>GlobalKTable</code></a></dd> |
| <dd><code>GV</code> - the value type of the <a href="GlobalKTable.html" title="interface in org.apache.kafka.streams.kstream"><code>GlobalKTable</code></a></dd> |
| <dd><code>RV</code> - the value type of the resulting <code>KStream</code></dd> |
| <dt>Parameters:</dt> |
| <dd><code>globalTable</code> - the <a href="GlobalKTable.html" title="interface in org.apache.kafka.streams.kstream"><code>GlobalKTable</code></a> to be joined with this stream</dd> |
| <dd><code>keySelector</code> - instance of <a href="KeyValueMapper.html" title="interface in org.apache.kafka.streams.kstream"><code>KeyValueMapper</code></a> used to map from the (key, value) of this stream |
| to the key of the <a href="GlobalKTable.html" title="interface in org.apache.kafka.streams.kstream"><code>GlobalKTable</code></a></dd> |
| <dd><code>joiner</code> - a <a href="ValueJoinerWithKey.html" title="interface in org.apache.kafka.streams.kstream"><code>ValueJoinerWithKey</code></a> that computes the join result for a pair of matching records</dd> |
| <dd><code>named</code> - a <a href="Named.html" title="class in org.apache.kafka.streams.kstream"><code>Named</code></a> config used to name the processor in the topology</dd> |
| <dt>Returns:</dt> |
| <dd>a <code>KStream</code> that contains join-records for each key and values computed by the given |
| <a href="ValueJoinerWithKey.html" title="interface in org.apache.kafka.streams.kstream"><code>ValueJoinerWithKey</code></a>, one output for each input <code>KStream</code> record</dd> |
| <dt>See Also:</dt> |
| <dd> |
| <ul class="see-list-long"> |
| <li><a href="#leftJoin(org.apache.kafka.streams.kstream.GlobalKTable,org.apache.kafka.streams.kstream.KeyValueMapper,org.apache.kafka.streams.kstream.ValueJoinerWithKey)"><code>leftJoin(GlobalKTable, KeyValueMapper, ValueJoinerWithKey)</code></a></li> |
| </ul> |
| </dd> |
| </dl> |
| </section> |
| </li> |
| <li> |
| <section class="detail" id="leftJoin(org.apache.kafka.streams.kstream.GlobalKTable,org.apache.kafka.streams.kstream.KeyValueMapper,org.apache.kafka.streams.kstream.ValueJoiner)"> |
| <h3>leftJoin</h3> |
| <div class="member-signature"><span class="type-parameters"><GK,<wbr> |
| GV,<wbr> |
| RV></span> <span class="return-type"><a href="KStream.html" title="interface in org.apache.kafka.streams.kstream">KStream</a><<a href="KStream.html" title="type parameter in KStream">K</a>,<wbr>RV></span> <span class="element-name">leftJoin</span><wbr><span class="parameters">(<a href="GlobalKTable.html" title="interface in org.apache.kafka.streams.kstream">GlobalKTable</a><GK,<wbr>GV> globalTable, |
| <a href="KeyValueMapper.html" title="interface in org.apache.kafka.streams.kstream">KeyValueMapper</a><? super <a href="KStream.html" title="type parameter in KStream">K</a>,<wbr>? super <a href="KStream.html" title="type parameter in KStream">V</a>,<wbr>? extends GK> keySelector, |
| <a href="ValueJoiner.html" title="interface in org.apache.kafka.streams.kstream">ValueJoiner</a><? super <a href="KStream.html" title="type parameter in KStream">V</a>,<wbr>? super GV,<wbr>? extends RV> valueJoiner)</span></div> |
| <div class="block">Join records of this stream with <a href="GlobalKTable.html" title="interface in org.apache.kafka.streams.kstream"><code>GlobalKTable</code></a>'s records using non-windowed left equi join. |
| In contrast to <a href="#join(org.apache.kafka.streams.kstream.GlobalKTable,org.apache.kafka.streams.kstream.KeyValueMapper,org.apache.kafka.streams.kstream.ValueJoiner)"><code>inner-join</code></a>, all records from this stream |
| will produce an output record (cf. below). |
| The join is a primary key table lookup join with join attribute |
| <code>keyValueMapper.map(stream.keyValue) == table.key</code>. |
| "Table lookup join" means, that results are only computed if <code>KStream</code> records are processed. |
| This is done by performing a lookup for matching records in the <em>current</em> internal <a href="GlobalKTable.html" title="interface in org.apache.kafka.streams.kstream"><code>GlobalKTable</code></a> |
| state. |
| In contrast, processing <a href="GlobalKTable.html" title="interface in org.apache.kafka.streams.kstream"><code>GlobalKTable</code></a> input records will only update the internal <a href="GlobalKTable.html" title="interface in org.apache.kafka.streams.kstream"><code>GlobalKTable</code></a> |
| state and will not produce any result records. |
| <p> |
| For each <code>KStream</code> record whether or not it finds a corresponding record in <a href="GlobalKTable.html" title="interface in org.apache.kafka.streams.kstream"><code>GlobalKTable</code></a> the |
| provided <a href="ValueJoiner.html" title="interface in org.apache.kafka.streams.kstream"><code>ValueJoiner</code></a> will be called to compute a value (with arbitrary type) for the result record. |
| The key of the result record is the same as this <code>KStream</code>. |
| If a <code>KStream</code> input record key or value is <code>null</code> the record will not be included in the join |
| operation and thus no output record will be added to the resulting <code>KStream</code>. |
| If <code>keyValueMapper</code> returns <code>null</code> implying no match exists, a <code>null</code> value will be |
| provided to <a href="ValueJoiner.html" title="interface in org.apache.kafka.streams.kstream"><code>ValueJoiner</code></a>. |
| If no <a href="GlobalKTable.html" title="interface in org.apache.kafka.streams.kstream"><code>GlobalKTable</code></a> record was found during lookup, a <code>null</code> value will be provided to |
| <a href="ValueJoiner.html" title="interface in org.apache.kafka.streams.kstream"><code>ValueJoiner</code></a>.</div> |
| <dl class="notes"> |
| <dt>Type Parameters:</dt> |
| <dd><code>GK</code> - the key type of <a href="GlobalKTable.html" title="interface in org.apache.kafka.streams.kstream"><code>GlobalKTable</code></a></dd> |
| <dd><code>GV</code> - the value type of the <a href="GlobalKTable.html" title="interface in org.apache.kafka.streams.kstream"><code>GlobalKTable</code></a></dd> |
| <dd><code>RV</code> - the value type of the resulting <code>KStream</code></dd> |
| <dt>Parameters:</dt> |
| <dd><code>globalTable</code> - the <a href="GlobalKTable.html" title="interface in org.apache.kafka.streams.kstream"><code>GlobalKTable</code></a> to be joined with this stream</dd> |
| <dd><code>keySelector</code> - instance of <a href="KeyValueMapper.html" title="interface in org.apache.kafka.streams.kstream"><code>KeyValueMapper</code></a> used to map from the (key, value) of this stream |
| to the key of the <a href="GlobalKTable.html" title="interface in org.apache.kafka.streams.kstream"><code>GlobalKTable</code></a></dd> |
| <dd><code>valueJoiner</code> - a <a href="ValueJoiner.html" title="interface in org.apache.kafka.streams.kstream"><code>ValueJoiner</code></a> that computes the join result for a pair of matching records</dd> |
| <dt>Returns:</dt> |
| <dd>a <code>KStream</code> that contains join-records for each key and values computed by the given |
| <a href="ValueJoiner.html" title="interface in org.apache.kafka.streams.kstream"><code>ValueJoiner</code></a>, one output for each input <code>KStream</code> record</dd> |
| <dt>See Also:</dt> |
| <dd> |
| <ul class="see-list-long"> |
| <li><a href="#join(org.apache.kafka.streams.kstream.GlobalKTable,org.apache.kafka.streams.kstream.KeyValueMapper,org.apache.kafka.streams.kstream.ValueJoiner)"><code>join(GlobalKTable, KeyValueMapper, ValueJoiner)</code></a></li> |
| </ul> |
| </dd> |
| </dl> |
| </section> |
| </li> |
| <li> |
| <section class="detail" id="leftJoin(org.apache.kafka.streams.kstream.GlobalKTable,org.apache.kafka.streams.kstream.KeyValueMapper,org.apache.kafka.streams.kstream.ValueJoinerWithKey)"> |
| <h3>leftJoin</h3> |
| <div class="member-signature"><span class="type-parameters"><GK,<wbr> |
| GV,<wbr> |
| RV></span> <span class="return-type"><a href="KStream.html" title="interface in org.apache.kafka.streams.kstream">KStream</a><<a href="KStream.html" title="type parameter in KStream">K</a>,<wbr>RV></span> <span class="element-name">leftJoin</span><wbr><span class="parameters">(<a href="GlobalKTable.html" title="interface in org.apache.kafka.streams.kstream">GlobalKTable</a><GK,<wbr>GV> globalTable, |
| <a href="KeyValueMapper.html" title="interface in org.apache.kafka.streams.kstream">KeyValueMapper</a><? super <a href="KStream.html" title="type parameter in KStream">K</a>,<wbr>? super <a href="KStream.html" title="type parameter in KStream">V</a>,<wbr>? extends GK> keySelector, |
| <a href="ValueJoinerWithKey.html" title="interface in org.apache.kafka.streams.kstream">ValueJoinerWithKey</a><? super <a href="KStream.html" title="type parameter in KStream">K</a>,<wbr>? super <a href="KStream.html" title="type parameter in KStream">V</a>,<wbr>? super GV,<wbr>? extends RV> valueJoiner)</span></div> |
| <div class="block">Join records of this stream with <a href="GlobalKTable.html" title="interface in org.apache.kafka.streams.kstream"><code>GlobalKTable</code></a>'s records using non-windowed left equi join. |
| In contrast to <a href="#join(org.apache.kafka.streams.kstream.GlobalKTable,org.apache.kafka.streams.kstream.KeyValueMapper,org.apache.kafka.streams.kstream.ValueJoinerWithKey)"><code>inner-join</code></a>, all records from this stream |
| will produce an output record (cf. below). |
| The join is a primary key table lookup join with join attribute |
| <code>keyValueMapper.map(stream.keyValue) == table.key</code>. |
| "Table lookup join" means, that results are only computed if <code>KStream</code> records are processed. |
| This is done by performing a lookup for matching records in the <em>current</em> internal <a href="GlobalKTable.html" title="interface in org.apache.kafka.streams.kstream"><code>GlobalKTable</code></a> |
| state. |
| In contrast, processing <a href="GlobalKTable.html" title="interface in org.apache.kafka.streams.kstream"><code>GlobalKTable</code></a> input records will only update the internal <a href="GlobalKTable.html" title="interface in org.apache.kafka.streams.kstream"><code>GlobalKTable</code></a> |
| state and will not produce any result records. |
| <p> |
| For each <code>KStream</code> record whether or not it finds a corresponding record in <a href="GlobalKTable.html" title="interface in org.apache.kafka.streams.kstream"><code>GlobalKTable</code></a> the |
| provided <a href="ValueJoinerWithKey.html" title="interface in org.apache.kafka.streams.kstream"><code>ValueJoinerWithKey</code></a> will be called to compute a value (with arbitrary type) for the result record. |
| The key of the result record is the same as this <code>KStream</code>. |
| Note that the key is read-only and should not be modified, as this can lead to undefined behaviour. |
| If a <code>KStream</code> input record key or value is <code>null</code> the record will not be included in the join |
| operation and thus no output record will be added to the resulting <code>KStream</code>. |
| If <code>keyValueMapper</code> returns <code>null</code> implying no match exists, a <code>null</code> value will be |
| provided to <a href="ValueJoinerWithKey.html" title="interface in org.apache.kafka.streams.kstream"><code>ValueJoinerWithKey</code></a>. |
| If no <a href="GlobalKTable.html" title="interface in org.apache.kafka.streams.kstream"><code>GlobalKTable</code></a> record was found during lookup, a <code>null</code> value will be provided to |
| <a href="ValueJoiner.html" title="interface in org.apache.kafka.streams.kstream"><code>ValueJoiner</code></a>.</div> |
| <dl class="notes"> |
| <dt>Type Parameters:</dt> |
| <dd><code>GK</code> - the key type of <a href="GlobalKTable.html" title="interface in org.apache.kafka.streams.kstream"><code>GlobalKTable</code></a></dd> |
| <dd><code>GV</code> - the value type of the <a href="GlobalKTable.html" title="interface in org.apache.kafka.streams.kstream"><code>GlobalKTable</code></a></dd> |
| <dd><code>RV</code> - the value type of the resulting <code>KStream</code></dd> |
| <dt>Parameters:</dt> |
| <dd><code>globalTable</code> - the <a href="GlobalKTable.html" title="interface in org.apache.kafka.streams.kstream"><code>GlobalKTable</code></a> to be joined with this stream</dd> |
| <dd><code>keySelector</code> - instance of <a href="KeyValueMapper.html" title="interface in org.apache.kafka.streams.kstream"><code>KeyValueMapper</code></a> used to map from the (key, value) of this stream |
| to the key of the <a href="GlobalKTable.html" title="interface in org.apache.kafka.streams.kstream"><code>GlobalKTable</code></a></dd> |
| <dd><code>valueJoiner</code> - a <a href="ValueJoinerWithKey.html" title="interface in org.apache.kafka.streams.kstream"><code>ValueJoinerWithKey</code></a> that computes the join result for a pair of matching records</dd> |
| <dt>Returns:</dt> |
| <dd>a <code>KStream</code> that contains join-records for each key and values computed by the given |
| <a href="ValueJoinerWithKey.html" title="interface in org.apache.kafka.streams.kstream"><code>ValueJoinerWithKey</code></a>, one output for each input <code>KStream</code> record</dd> |
| <dt>See Also:</dt> |
| <dd> |
| <ul class="see-list-long"> |
| <li><a href="#join(org.apache.kafka.streams.kstream.GlobalKTable,org.apache.kafka.streams.kstream.KeyValueMapper,org.apache.kafka.streams.kstream.ValueJoinerWithKey)"><code>join(GlobalKTable, KeyValueMapper, ValueJoinerWithKey)</code></a></li> |
| </ul> |
| </dd> |
| </dl> |
| </section> |
| </li> |
| <li> |
| <section class="detail" id="leftJoin(org.apache.kafka.streams.kstream.GlobalKTable,org.apache.kafka.streams.kstream.KeyValueMapper,org.apache.kafka.streams.kstream.ValueJoiner,org.apache.kafka.streams.kstream.Named)"> |
| <h3>leftJoin</h3> |
| <div class="member-signature"><span class="type-parameters"><GK,<wbr> |
| GV,<wbr> |
| RV></span> <span class="return-type"><a href="KStream.html" title="interface in org.apache.kafka.streams.kstream">KStream</a><<a href="KStream.html" title="type parameter in KStream">K</a>,<wbr>RV></span> <span class="element-name">leftJoin</span><wbr><span class="parameters">(<a href="GlobalKTable.html" title="interface in org.apache.kafka.streams.kstream">GlobalKTable</a><GK,<wbr>GV> globalTable, |
| <a href="KeyValueMapper.html" title="interface in org.apache.kafka.streams.kstream">KeyValueMapper</a><? super <a href="KStream.html" title="type parameter in KStream">K</a>,<wbr>? super <a href="KStream.html" title="type parameter in KStream">V</a>,<wbr>? extends GK> keySelector, |
| <a href="ValueJoiner.html" title="interface in org.apache.kafka.streams.kstream">ValueJoiner</a><? super <a href="KStream.html" title="type parameter in KStream">V</a>,<wbr>? super GV,<wbr>? extends RV> valueJoiner, |
| <a href="Named.html" title="class in org.apache.kafka.streams.kstream">Named</a> named)</span></div> |
| <div class="block">Join records of this stream with <a href="GlobalKTable.html" title="interface in org.apache.kafka.streams.kstream"><code>GlobalKTable</code></a>'s records using non-windowed left equi join. |
| In contrast to <a href="#join(org.apache.kafka.streams.kstream.GlobalKTable,org.apache.kafka.streams.kstream.KeyValueMapper,org.apache.kafka.streams.kstream.ValueJoiner)"><code>inner-join</code></a>, all records from this stream |
| will produce an output record (cf. below). |
| The join is a primary key table lookup join with join attribute |
| <code>keyValueMapper.map(stream.keyValue) == table.key</code>. |
| "Table lookup join" means, that results are only computed if <code>KStream</code> records are processed. |
| This is done by performing a lookup for matching records in the <em>current</em> internal <a href="GlobalKTable.html" title="interface in org.apache.kafka.streams.kstream"><code>GlobalKTable</code></a> |
| state. |
| In contrast, processing <a href="GlobalKTable.html" title="interface in org.apache.kafka.streams.kstream"><code>GlobalKTable</code></a> input records will only update the internal <a href="GlobalKTable.html" title="interface in org.apache.kafka.streams.kstream"><code>GlobalKTable</code></a> |
| state and will not produce any result records. |
| <p> |
| For each <code>KStream</code> record whether or not it finds a corresponding record in <a href="GlobalKTable.html" title="interface in org.apache.kafka.streams.kstream"><code>GlobalKTable</code></a> the |
| provided <a href="ValueJoiner.html" title="interface in org.apache.kafka.streams.kstream"><code>ValueJoiner</code></a> will be called to compute a value (with arbitrary type) for the result record. |
| The key of the result record is the same as this <code>KStream</code>. |
| If a <code>KStream</code> input record key or value is <code>null</code> the record will not be included in the join |
| operation and thus no output record will be added to the resulting <code>KStream</code>. |
| If <code>keyValueMapper</code> returns <code>null</code> implying no match exists, a <code>null</code> value will be |
| provided to <a href="ValueJoiner.html" title="interface in org.apache.kafka.streams.kstream"><code>ValueJoiner</code></a>. |
| If no <a href="GlobalKTable.html" title="interface in org.apache.kafka.streams.kstream"><code>GlobalKTable</code></a> record was found during lookup, a <code>null</code> value will be provided to |
| <a href="ValueJoiner.html" title="interface in org.apache.kafka.streams.kstream"><code>ValueJoiner</code></a>.</div> |
| <dl class="notes"> |
| <dt>Type Parameters:</dt> |
| <dd><code>GK</code> - the key type of <a href="GlobalKTable.html" title="interface in org.apache.kafka.streams.kstream"><code>GlobalKTable</code></a></dd> |
| <dd><code>GV</code> - the value type of the <a href="GlobalKTable.html" title="interface in org.apache.kafka.streams.kstream"><code>GlobalKTable</code></a></dd> |
| <dd><code>RV</code> - the value type of the resulting <code>KStream</code></dd> |
| <dt>Parameters:</dt> |
| <dd><code>globalTable</code> - the <a href="GlobalKTable.html" title="interface in org.apache.kafka.streams.kstream"><code>GlobalKTable</code></a> to be joined with this stream</dd> |
| <dd><code>keySelector</code> - instance of <a href="KeyValueMapper.html" title="interface in org.apache.kafka.streams.kstream"><code>KeyValueMapper</code></a> used to map from the (key, value) of this stream |
| to the key of the <a href="GlobalKTable.html" title="interface in org.apache.kafka.streams.kstream"><code>GlobalKTable</code></a></dd> |
| <dd><code>valueJoiner</code> - a <a href="ValueJoiner.html" title="interface in org.apache.kafka.streams.kstream"><code>ValueJoiner</code></a> that computes the join result for a pair of matching records</dd> |
| <dd><code>named</code> - a <a href="Named.html" title="class in org.apache.kafka.streams.kstream"><code>Named</code></a> config used to name the processor in the topology</dd> |
| <dt>Returns:</dt> |
| <dd>a <code>KStream</code> that contains join-records for each key and values computed by the given |
| <a href="ValueJoiner.html" title="interface in org.apache.kafka.streams.kstream"><code>ValueJoiner</code></a>, one output for each input <code>KStream</code> record</dd> |
| <dt>See Also:</dt> |
| <dd> |
| <ul class="see-list-long"> |
| <li><a href="#join(org.apache.kafka.streams.kstream.GlobalKTable,org.apache.kafka.streams.kstream.KeyValueMapper,org.apache.kafka.streams.kstream.ValueJoiner)"><code>join(GlobalKTable, KeyValueMapper, ValueJoiner)</code></a></li> |
| </ul> |
| </dd> |
| </dl> |
| </section> |
| </li> |
| <li> |
| <section class="detail" id="leftJoin(org.apache.kafka.streams.kstream.GlobalKTable,org.apache.kafka.streams.kstream.KeyValueMapper,org.apache.kafka.streams.kstream.ValueJoinerWithKey,org.apache.kafka.streams.kstream.Named)"> |
| <h3>leftJoin</h3> |
| <div class="member-signature"><span class="type-parameters"><GK,<wbr> |
| GV,<wbr> |
| RV></span> <span class="return-type"><a href="KStream.html" title="interface in org.apache.kafka.streams.kstream">KStream</a><<a href="KStream.html" title="type parameter in KStream">K</a>,<wbr>RV></span> <span class="element-name">leftJoin</span><wbr><span class="parameters">(<a href="GlobalKTable.html" title="interface in org.apache.kafka.streams.kstream">GlobalKTable</a><GK,<wbr>GV> globalTable, |
| <a href="KeyValueMapper.html" title="interface in org.apache.kafka.streams.kstream">KeyValueMapper</a><? super <a href="KStream.html" title="type parameter in KStream">K</a>,<wbr>? super <a href="KStream.html" title="type parameter in KStream">V</a>,<wbr>? extends GK> keySelector, |
| <a href="ValueJoinerWithKey.html" title="interface in org.apache.kafka.streams.kstream">ValueJoinerWithKey</a><? super <a href="KStream.html" title="type parameter in KStream">K</a>,<wbr>? super <a href="KStream.html" title="type parameter in KStream">V</a>,<wbr>? super GV,<wbr>? extends RV> valueJoiner, |
| <a href="Named.html" title="class in org.apache.kafka.streams.kstream">Named</a> named)</span></div> |
| <div class="block">Join records of this stream with <a href="GlobalKTable.html" title="interface in org.apache.kafka.streams.kstream"><code>GlobalKTable</code></a>'s records using non-windowed left equi join. |
| In contrast to <a href="#join(org.apache.kafka.streams.kstream.GlobalKTable,org.apache.kafka.streams.kstream.KeyValueMapper,org.apache.kafka.streams.kstream.ValueJoinerWithKey)"><code>inner-join</code></a>, all records from this stream |
| will produce an output record (cf. below). |
| The join is a primary key table lookup join with join attribute |
| <code>keyValueMapper.map(stream.keyValue) == table.key</code>. |
| "Table lookup join" means, that results are only computed if <code>KStream</code> records are processed. |
| This is done by performing a lookup for matching records in the <em>current</em> internal <a href="GlobalKTable.html" title="interface in org.apache.kafka.streams.kstream"><code>GlobalKTable</code></a> |
| state. |
| In contrast, processing <a href="GlobalKTable.html" title="interface in org.apache.kafka.streams.kstream"><code>GlobalKTable</code></a> input records will only update the internal <a href="GlobalKTable.html" title="interface in org.apache.kafka.streams.kstream"><code>GlobalKTable</code></a> |
| state and will not produce any result records. |
| <p> |
| For each <code>KStream</code> record whether or not it finds a corresponding record in <a href="GlobalKTable.html" title="interface in org.apache.kafka.streams.kstream"><code>GlobalKTable</code></a> the |
| provided <a href="ValueJoinerWithKey.html" title="interface in org.apache.kafka.streams.kstream"><code>ValueJoinerWithKey</code></a> will be called to compute a value (with arbitrary type) for the result record. |
| The key of the result record is the same as this <code>KStream</code>. |
| If a <code>KStream</code> input record key or value is <code>null</code> the record will not be included in the join |
| operation and thus no output record will be added to the resulting <code>KStream</code>. |
| If <code>keyValueMapper</code> returns <code>null</code> implying no match exists, a <code>null</code> value will be |
| provided to <a href="ValueJoinerWithKey.html" title="interface in org.apache.kafka.streams.kstream"><code>ValueJoinerWithKey</code></a>. |
| If no <a href="GlobalKTable.html" title="interface in org.apache.kafka.streams.kstream"><code>GlobalKTable</code></a> record was found during lookup, a <code>null</code> value will be provided to |
| <a href="ValueJoinerWithKey.html" title="interface in org.apache.kafka.streams.kstream"><code>ValueJoinerWithKey</code></a>.</div> |
| <dl class="notes"> |
| <dt>Type Parameters:</dt> |
| <dd><code>GK</code> - the key type of <a href="GlobalKTable.html" title="interface in org.apache.kafka.streams.kstream"><code>GlobalKTable</code></a></dd> |
| <dd><code>GV</code> - the value type of the <a href="GlobalKTable.html" title="interface in org.apache.kafka.streams.kstream"><code>GlobalKTable</code></a></dd> |
| <dd><code>RV</code> - the value type of the resulting <code>KStream</code></dd> |
| <dt>Parameters:</dt> |
| <dd><code>globalTable</code> - the <a href="GlobalKTable.html" title="interface in org.apache.kafka.streams.kstream"><code>GlobalKTable</code></a> to be joined with this stream</dd> |
| <dd><code>keySelector</code> - instance of <a href="KeyValueMapper.html" title="interface in org.apache.kafka.streams.kstream"><code>KeyValueMapper</code></a> used to map from the (key, value) of this stream |
| to the key of the <a href="GlobalKTable.html" title="interface in org.apache.kafka.streams.kstream"><code>GlobalKTable</code></a></dd> |
| <dd><code>valueJoiner</code> - a <a href="ValueJoinerWithKey.html" title="interface in org.apache.kafka.streams.kstream"><code>ValueJoinerWithKey</code></a> that computes the join result for a pair of matching records</dd> |
| <dd><code>named</code> - a <a href="Named.html" title="class in org.apache.kafka.streams.kstream"><code>Named</code></a> config used to name the processor in the topology</dd> |
| <dt>Returns:</dt> |
| <dd>a <code>KStream</code> that contains join-records for each key and values computed by the given |
| <a href="ValueJoinerWithKey.html" title="interface in org.apache.kafka.streams.kstream"><code>ValueJoinerWithKey</code></a>, one output for each input <code>KStream</code> record</dd> |
| <dt>See Also:</dt> |
| <dd> |
| <ul class="see-list-long"> |
| <li><a href="#join(org.apache.kafka.streams.kstream.GlobalKTable,org.apache.kafka.streams.kstream.KeyValueMapper,org.apache.kafka.streams.kstream.ValueJoinerWithKey)"><code>join(GlobalKTable, KeyValueMapper, ValueJoinerWithKey)</code></a></li> |
| </ul> |
| </dd> |
| </dl> |
| </section> |
| </li> |
| <li> |
| <section class="detail" id="transform(org.apache.kafka.streams.kstream.TransformerSupplier,java.lang.String...)"> |
| <h3>transform</h3> |
| <div class="member-signature"><span class="type-parameters"><K1,<wbr> |
| V1></span> <span class="return-type"><a href="KStream.html" title="interface in org.apache.kafka.streams.kstream">KStream</a><K1,<wbr>V1></span> <span class="element-name">transform</span><wbr><span class="parameters">(<a href="TransformerSupplier.html" title="interface in org.apache.kafka.streams.kstream">TransformerSupplier</a><? super <a href="KStream.html" title="type parameter in KStream">K</a>,<wbr>? super <a href="KStream.html" title="type parameter in KStream">V</a>,<wbr><a href="../KeyValue.html" title="class in org.apache.kafka.streams">KeyValue</a><K1,<wbr>V1>> transformerSupplier, |
| <a href="https://docs.oracle.com/en/java/javase/17/docs/api/java.base/java/lang/String.html" title="class or interface in java.lang" class="external-link">String</a>... stateStoreNames)</span></div> |
| <div class="block">Transform each record of the input stream into zero or one record in the output stream (both key and value type |
| can be altered arbitrarily). |
| A <a href="Transformer.html" title="interface in org.apache.kafka.streams.kstream"><code>Transformer</code></a> (provided by the given <a href="TransformerSupplier.html" title="interface in org.apache.kafka.streams.kstream"><code>TransformerSupplier</code></a>) is applied to each input record and |
| returns zero or one output record. |
| Thus, an input record <code><K,V></code> can be transformed into an output record <code><K':V'></code>. |
| Attaching a state store makes this a stateful record-by-record operation (cf. <a href="#map(org.apache.kafka.streams.kstream.KeyValueMapper)"><code>map()</code></a>). |
| If you choose not to attach one, this operation is similar to the stateless <a href="#map(org.apache.kafka.streams.kstream.KeyValueMapper)"><code>map()</code></a> |
| but allows access to the <code>ProcessorContext</code> and record metadata. |
| This is essentially mixing the Processor API into the DSL, and provides all the functionality of the PAPI. |
| Furthermore, via <a href="../processor/Punctuator.html#punctuate(long)"><code>Punctuator#punctuate()</code></a>, |
| the processing progress can be observed and additional periodic actions can be performed. |
| <p> |
| In order for the transformer to use state stores, the stores must be added to the topology and connected to the |
| transformer using at least one of two strategies (though it's not required to connect global state stores; read-only |
| access to global state stores is available by default). |
| <p> |
| The first strategy is to manually add the <a href="../state/StoreBuilder.html" title="interface in org.apache.kafka.streams.state"><code>StoreBuilder</code></a>s via <a href="../Topology.html#addStateStore(org.apache.kafka.streams.state.StoreBuilder,java.lang.String...)"><code>Topology.addStateStore(StoreBuilder, String...)</code></a>, |
| and specify the store names via <code>stateStoreNames</code> so they will be connected to the transformer. |
| <pre><code> |
| // create store |
| StoreBuilder<KeyValueStore<String,String>> keyValueStoreBuilder = |
| Stores.keyValueStoreBuilder(Stores.persistentKeyValueStore("myTransformState"), |
| Serdes.String(), |
| Serdes.String()); |
| // add store |
| builder.addStateStore(keyValueStoreBuilder); |
| |
| KStream outputStream = inputStream.transform(new TransformerSupplier() { |
| public Transformer get() { |
| return new MyTransformer(); |
| } |
| }, "myTransformState"); |
| </code></pre> |
| The second strategy is for the given <a href="TransformerSupplier.html" title="interface in org.apache.kafka.streams.kstream"><code>TransformerSupplier</code></a> to implement <a href="../processor/ConnectedStoreProvider.html#stores()"><code>ConnectedStoreProvider.stores()</code></a>, |
| which provides the <a href="../state/StoreBuilder.html" title="interface in org.apache.kafka.streams.state"><code>StoreBuilder</code></a>s to be automatically added to the topology and connected to the transformer. |
| <pre><code> |
| class MyTransformerSupplier implements TransformerSupplier { |
| // supply transformer |
| Transformer get() { |
| return new MyTransformer(); |
| } |
| |
| // provide store(s) that will be added and connected to the associated transformer |
| // the store name from the builder ("myTransformState") is used to access the store later via the ProcessorContext |
| Set<StoreBuilder> stores() { |
| StoreBuilder<KeyValueStore<String, String>> keyValueStoreBuilder = |
| Stores.keyValueStoreBuilder(Stores.persistentKeyValueStore("myTransformState"), |
| Serdes.String(), |
| Serdes.String()); |
| return Collections.singleton(keyValueStoreBuilder); |
| } |
| } |
| |
| ... |
| |
| KStream outputStream = inputStream.transform(new MyTransformerSupplier()); |
| </code></pre> |
| <p> |
| With either strategy, within the <a href="Transformer.html" title="interface in org.apache.kafka.streams.kstream"><code>Transformer</code></a>, the state is obtained via the <a href="../processor/api/ProcessorContext.html" title="interface in org.apache.kafka.streams.processor.api"><code>ProcessorContext</code></a>. |
| To trigger periodic actions via <a href="../processor/Punctuator.html#punctuate(long)"><code>punctuate()</code></a>, |
| a schedule must be registered. |
| The <a href="Transformer.html" title="interface in org.apache.kafka.streams.kstream"><code>Transformer</code></a> must return a <a href="../KeyValue.html" title="class in org.apache.kafka.streams"><code>KeyValue</code></a> type in <a href="Transformer.html#transform(K,V)"><code>transform()</code></a>. |
| The return value of <a href="Transformer.html#transform(K,V)"><code>Transformer#transform()</code></a> may be <code>null</code>, |
| in which case no record is emitted. |
| <pre><code> |
| class MyTransformer implements Transformer { |
| private ProcessorContext context; |
| private StateStore state; |
| |
| void init(ProcessorContext context) { |
| this.context = context; |
| this.state = context.getStateStore("myTransformState"); |
| // punctuate each second; can access this.state |
| context.schedule(Duration.ofSeconds(1), PunctuationType.WALL_CLOCK_TIME, new Punctuator(..)); |
| } |
| |
| KeyValue transform(K key, V value) { |
| // can access this.state |
| return new KeyValue(key, value); // can emit a single value via return -- can also be null |
| } |
| |
| void close() { |
| // can access this.state |
| } |
| } |
| </code></pre> |
| Even if any upstream operation was key-changing, no auto-repartition is triggered. |
| If repartitioning is required, a call to <a href="#repartition()"><code>repartition()</code></a> should be performed before <code>transform()</code>. |
| <p> |
| Transforming records might result in an internal data redistribution if a key based operator (like an aggregation |
| or join) is applied to the result <code>KStream</code>. |
| (cf. <a href="#transformValues(org.apache.kafka.streams.kstream.ValueTransformerSupplier,java.lang.String...)"><code>transformValues()</code></a> ) |
| <p> |
| Note that it is possible to emit multiple records for each input record by using |
| <a href="../processor/ProcessorContext.html#forward(K,V)"><code>context#forward()</code></a> in |
| <a href="Transformer.html#transform(K,V)"><code>Transformer#transform()</code></a> and |
| <a href="../processor/Punctuator.html#punctuate(long)"><code>Punctuator#punctuate()</code></a>. |
| Be aware that a mismatch between the types of the emitted records and the type of the stream would only be |
| detected at runtime. |
| To ensure type-safety at compile-time, |
| <a href="../processor/ProcessorContext.html#forward(K,V)"><code>context#forward()</code></a> should |
| not be used in <a href="Transformer.html#transform(K,V)"><code>Transformer#transform()</code></a> and |
| <a href="../processor/Punctuator.html#punctuate(long)"><code>Punctuator#punctuate()</code></a>. |
| If in <a href="Transformer.html#transform(K,V)"><code>Transformer#transform()</code></a> multiple records need to be emitted |
| for each input record, it is recommended to use <a href="#flatTransform(org.apache.kafka.streams.kstream.TransformerSupplier,java.lang.String...)"><code>flatTransform()</code></a>. |
| The supplier should always generate a new instance each time <a href="TransformerSupplier.html#get()"><code>TransformerSupplier.get()</code></a> gets called. Creating |
| a single <a href="Transformer.html" title="interface in org.apache.kafka.streams.kstream"><code>Transformer</code></a> object and returning the same object reference in <a href="TransformerSupplier.html#get()"><code>TransformerSupplier.get()</code></a> would be |
| a violation of the supplier pattern and leads to runtime exceptions.</div> |
| <dl class="notes"> |
| <dt>Type Parameters:</dt> |
| <dd><code>K1</code> - the key type of the new stream</dd> |
| <dd><code>V1</code> - the value type of the new stream</dd> |
| <dt>Parameters:</dt> |
| <dd><code>transformerSupplier</code> - an instance of <a href="TransformerSupplier.html" title="interface in org.apache.kafka.streams.kstream"><code>TransformerSupplier</code></a> that generates a newly constructed |
| <a href="Transformer.html" title="interface in org.apache.kafka.streams.kstream"><code>Transformer</code></a></dd> |
| <dd><code>stateStoreNames</code> - the names of the state stores used by the processor; not required if the supplier |
| implements <a href="../processor/ConnectedStoreProvider.html#stores()"><code>ConnectedStoreProvider.stores()</code></a></dd> |
| <dt>Returns:</dt> |
| <dd>a <code>KStream</code> that contains more or less records with new key and value (possibly of different type)</dd> |
| <dt>See Also:</dt> |
| <dd> |
| <ul class="see-list-long"> |
| <li><a href="#map(org.apache.kafka.streams.kstream.KeyValueMapper)"><code>map(KeyValueMapper)</code></a></li> |
| <li><a href="#flatTransform(org.apache.kafka.streams.kstream.TransformerSupplier,java.lang.String...)"><code>flatTransform(TransformerSupplier, String...)</code></a></li> |
| <li><a href="#transformValues(org.apache.kafka.streams.kstream.ValueTransformerSupplier,java.lang.String...)"><code>transformValues(ValueTransformerSupplier, String...)</code></a></li> |
| <li><a href="#transformValues(org.apache.kafka.streams.kstream.ValueTransformerWithKeySupplier,java.lang.String...)"><code>transformValues(ValueTransformerWithKeySupplier, String...)</code></a></li> |
| <li><a href="#process(org.apache.kafka.streams.processor.api.ProcessorSupplier,java.lang.String...)"><code>process(ProcessorSupplier, String...)</code></a></li> |
| </ul> |
| </dd> |
| </dl> |
| </section> |
| </li> |
| <li> |
| <section class="detail" id="transform(org.apache.kafka.streams.kstream.TransformerSupplier,org.apache.kafka.streams.kstream.Named,java.lang.String...)"> |
| <h3>transform</h3> |
| <div class="member-signature"><span class="type-parameters"><K1,<wbr> |
| V1></span> <span class="return-type"><a href="KStream.html" title="interface in org.apache.kafka.streams.kstream">KStream</a><K1,<wbr>V1></span> <span class="element-name">transform</span><wbr><span class="parameters">(<a href="TransformerSupplier.html" title="interface in org.apache.kafka.streams.kstream">TransformerSupplier</a><? super <a href="KStream.html" title="type parameter in KStream">K</a>,<wbr>? super <a href="KStream.html" title="type parameter in KStream">V</a>,<wbr><a href="../KeyValue.html" title="class in org.apache.kafka.streams">KeyValue</a><K1,<wbr>V1>> transformerSupplier, |
| <a href="Named.html" title="class in org.apache.kafka.streams.kstream">Named</a> named, |
| <a href="https://docs.oracle.com/en/java/javase/17/docs/api/java.base/java/lang/String.html" title="class or interface in java.lang" class="external-link">String</a>... stateStoreNames)</span></div> |
| <div class="block">Transform each record of the input stream into zero or one record in the output stream (both key and value type |
| can be altered arbitrarily). |
| A <a href="Transformer.html" title="interface in org.apache.kafka.streams.kstream"><code>Transformer</code></a> (provided by the given <a href="TransformerSupplier.html" title="interface in org.apache.kafka.streams.kstream"><code>TransformerSupplier</code></a>) is applied to each input record and |
| returns zero or one output record. |
| Thus, an input record <code><K,V></code> can be transformed into an output record <code><K':V'></code>. |
| Attaching a state store makes this a stateful record-by-record operation (cf. <a href="#map(org.apache.kafka.streams.kstream.KeyValueMapper)"><code>map()</code></a>). |
| If you choose not to attach one, this operation is similar to the stateless <a href="#map(org.apache.kafka.streams.kstream.KeyValueMapper)"><code>map()</code></a> |
| but allows access to the <code>ProcessorContext</code> and record metadata. |
| This is essentially mixing the Processor API into the DSL, and provides all the functionality of the PAPI. |
| Furthermore, via <a href="../processor/Punctuator.html#punctuate(long)"><code>Punctuator#punctuate()</code></a>, |
| the processing progress can be observed and additional periodic actions can be performed. |
| <p> |
| In order for the transformer to use state stores, the stores must be added to the topology and connected to the |
| transformer using at least one of two strategies (though it's not required to connect global state stores; read-only |
| access to global state stores is available by default). |
| <p> |
| The first strategy is to manually add the <a href="../state/StoreBuilder.html" title="interface in org.apache.kafka.streams.state"><code>StoreBuilder</code></a>s via <a href="../Topology.html#addStateStore(org.apache.kafka.streams.state.StoreBuilder,java.lang.String...)"><code>Topology.addStateStore(StoreBuilder, String...)</code></a>, |
| and specify the store names via <code>stateStoreNames</code> so they will be connected to the transformer. |
| <pre><code> |
| // create store |
| StoreBuilder<KeyValueStore<String,String>> keyValueStoreBuilder = |
| Stores.keyValueStoreBuilder(Stores.persistentKeyValueStore("myTransformState"), |
| Serdes.String(), |
| Serdes.String()); |
| // add store |
| builder.addStateStore(keyValueStoreBuilder); |
| |
| KStream outputStream = inputStream.transform(new TransformerSupplier() { |
| public Transformer get() { |
| return new MyTransformer(); |
| } |
| }, "myTransformState"); |
| </code></pre> |
| The second strategy is for the given <a href="TransformerSupplier.html" title="interface in org.apache.kafka.streams.kstream"><code>TransformerSupplier</code></a> to implement <a href="../processor/ConnectedStoreProvider.html#stores()"><code>ConnectedStoreProvider.stores()</code></a>, |
| which provides the <a href="../state/StoreBuilder.html" title="interface in org.apache.kafka.streams.state"><code>StoreBuilder</code></a>s to be automatically added to the topology and connected to the transformer. |
| <pre><code> |
| class MyTransformerSupplier implements TransformerSupplier { |
| // supply transformer |
| Transformer get() { |
| return new MyTransformer(); |
| } |
| |
| // provide store(s) that will be added and connected to the associated transformer |
| // the store name from the builder ("myTransformState") is used to access the store later via the ProcessorContext |
| Set<StoreBuilder> stores() { |
| StoreBuilder<KeyValueStore<String, String>> keyValueStoreBuilder = |
| Stores.keyValueStoreBuilder(Stores.persistentKeyValueStore("myTransformState"), |
| Serdes.String(), |
| Serdes.String()); |
| return Collections.singleton(keyValueStoreBuilder); |
| } |
| } |
| |
| ... |
| |
| KStream outputStream = inputStream.transform(new MyTransformerSupplier()); |
| </code></pre> |
| <p> |
| With either strategy, within the <a href="Transformer.html" title="interface in org.apache.kafka.streams.kstream"><code>Transformer</code></a>, the state is obtained via the <a href="../processor/api/ProcessorContext.html" title="interface in org.apache.kafka.streams.processor.api"><code>ProcessorContext</code></a>. |
| To trigger periodic actions via <a href="../processor/Punctuator.html#punctuate(long)"><code>punctuate()</code></a>, |
| a schedule must be registered. |
| The <a href="Transformer.html" title="interface in org.apache.kafka.streams.kstream"><code>Transformer</code></a> must return a <a href="../KeyValue.html" title="class in org.apache.kafka.streams"><code>KeyValue</code></a> type in <a href="Transformer.html#transform(K,V)"><code>transform()</code></a>. |
| The return value of <a href="Transformer.html#transform(K,V)"><code>Transformer#transform()</code></a> may be <code>null</code>, |
| in which case no record is emitted. |
| <pre><code> |
| class MyTransformer implements Transformer { |
| private ProcessorContext context; |
| private StateStore state; |
| |
| void init(ProcessorContext context) { |
| this.context = context; |
| this.state = context.getStateStore("myTransformState"); |
| // punctuate each second; can access this.state |
| context.schedule(Duration.ofSeconds(1), PunctuationType.WALL_CLOCK_TIME, new Punctuator(..)); |
| } |
| |
| KeyValue transform(K key, V value) { |
| // can access this.state |
| return new KeyValue(key, value); // can emit a single value via return -- can also be null |
| } |
| |
| void close() { |
| // can access this.state |
| } |
| } |
| </code></pre> |
| Even if any upstream operation was key-changing, no auto-repartition is triggered. |
| If repartitioning is required, a call to <a href="#repartition()"><code>repartition()</code></a> should be performed before <code>transform()</code>. |
| <p> |
| Transforming records might result in an internal data redistribution if a key based operator (like an aggregation |
| or join) is applied to the result <code>KStream</code>. |
| (cf. <a href="#transformValues(org.apache.kafka.streams.kstream.ValueTransformerSupplier,java.lang.String...)"><code>transformValues()</code></a> ) |
| <p> |
| Note that it is possible to emit multiple records for each input record by using |
| <a href="../processor/ProcessorContext.html#forward(K,V)"><code>context#forward()</code></a> in |
| <a href="Transformer.html#transform(K,V)"><code>Transformer#transform()</code></a> and |
| <a href="../processor/Punctuator.html#punctuate(long)"><code>Punctuator#punctuate()</code></a>. |
| Be aware that a mismatch between the types of the emitted records and the type of the stream would only be |
| detected at runtime. |
| To ensure type-safety at compile-time, |
| <a href="../processor/ProcessorContext.html#forward(K,V)"><code>context#forward()</code></a> should |
| not be used in <a href="Transformer.html#transform(K,V)"><code>Transformer#transform()</code></a> and |
| <a href="../processor/Punctuator.html#punctuate(long)"><code>Punctuator#punctuate()</code></a>. |
| If in <a href="Transformer.html#transform(K,V)"><code>Transformer#transform()</code></a> multiple records need to be emitted |
| for each input record, it is recommended to use <a href="#flatTransform(org.apache.kafka.streams.kstream.TransformerSupplier,java.lang.String...)"><code>flatTransform()</code></a>. |
| The supplier should always generate a new instance each time <a href="TransformerSupplier.html#get()"><code>TransformerSupplier.get()</code></a> gets called. Creating |
| a single <a href="Transformer.html" title="interface in org.apache.kafka.streams.kstream"><code>Transformer</code></a> object and returning the same object reference in <a href="TransformerSupplier.html#get()"><code>TransformerSupplier.get()</code></a> would be |
| a violation of the supplier pattern and leads to runtime exceptions.</div> |
| <dl class="notes"> |
| <dt>Type Parameters:</dt> |
| <dd><code>K1</code> - the key type of the new stream</dd> |
| <dd><code>V1</code> - the value type of the new stream</dd> |
| <dt>Parameters:</dt> |
| <dd><code>transformerSupplier</code> - an instance of <a href="TransformerSupplier.html" title="interface in org.apache.kafka.streams.kstream"><code>TransformerSupplier</code></a> that generates a newly constructed |
| <a href="Transformer.html" title="interface in org.apache.kafka.streams.kstream"><code>Transformer</code></a></dd> |
| <dd><code>named</code> - a <a href="Named.html" title="class in org.apache.kafka.streams.kstream"><code>Named</code></a> config used to name the processor in the topology</dd> |
| <dd><code>stateStoreNames</code> - the names of the state stores used by the processor; not required if the supplier |
| implements <a href="../processor/ConnectedStoreProvider.html#stores()"><code>ConnectedStoreProvider.stores()</code></a></dd> |
| <dt>Returns:</dt> |
| <dd>a <code>KStream</code> that contains more or less records with new key and value (possibly of different type)</dd> |
| <dt>See Also:</dt> |
| <dd> |
| <ul class="see-list-long"> |
| <li><a href="#map(org.apache.kafka.streams.kstream.KeyValueMapper)"><code>map(KeyValueMapper)</code></a></li> |
| <li><a href="#flatTransform(org.apache.kafka.streams.kstream.TransformerSupplier,java.lang.String...)"><code>flatTransform(TransformerSupplier, String...)</code></a></li> |
| <li><a href="#transformValues(org.apache.kafka.streams.kstream.ValueTransformerSupplier,java.lang.String...)"><code>transformValues(ValueTransformerSupplier, String...)</code></a></li> |
| <li><a href="#transformValues(org.apache.kafka.streams.kstream.ValueTransformerWithKeySupplier,java.lang.String...)"><code>transformValues(ValueTransformerWithKeySupplier, String...)</code></a></li> |
| <li><a href="#process(org.apache.kafka.streams.processor.api.ProcessorSupplier,java.lang.String...)"><code>process(ProcessorSupplier, String...)</code></a></li> |
| </ul> |
| </dd> |
| </dl> |
| </section> |
| </li> |
| <li> |
| <section class="detail" id="flatTransform(org.apache.kafka.streams.kstream.TransformerSupplier,java.lang.String...)"> |
| <h3>flatTransform</h3> |
| <div class="member-signature"><span class="type-parameters"><K1,<wbr> |
| V1></span> <span class="return-type"><a href="KStream.html" title="interface in org.apache.kafka.streams.kstream">KStream</a><K1,<wbr>V1></span> <span class="element-name">flatTransform</span><wbr><span class="parameters">(<a href="TransformerSupplier.html" title="interface in org.apache.kafka.streams.kstream">TransformerSupplier</a><? super <a href="KStream.html" title="type parameter in KStream">K</a>,<wbr>? super <a href="KStream.html" title="type parameter in KStream">V</a>,<wbr><a href="https://docs.oracle.com/en/java/javase/17/docs/api/java.base/java/lang/Iterable.html" title="class or interface in java.lang" class="external-link">Iterable</a><<a href="../KeyValue.html" title="class in org.apache.kafka.streams">KeyValue</a><K1,<wbr>V1>>> transformerSupplier, |
| <a href="https://docs.oracle.com/en/java/javase/17/docs/api/java.base/java/lang/String.html" title="class or interface in java.lang" class="external-link">String</a>... stateStoreNames)</span></div> |
| <div class="block">Transform each record of the input stream into zero or more records in the output stream (both key and value type |
| can be altered arbitrarily). |
| A <a href="Transformer.html" title="interface in org.apache.kafka.streams.kstream"><code>Transformer</code></a> (provided by the given <a href="TransformerSupplier.html" title="interface in org.apache.kafka.streams.kstream"><code>TransformerSupplier</code></a>) is applied to each input record and |
| returns zero or more output records. |
| Thus, an input record <code><K,V></code> can be transformed into output records <code><K':V'>, <K'':V''>, ...</code>. |
| Attaching a state store makes this a stateful record-by-record operation (cf. <a href="#flatMap(org.apache.kafka.streams.kstream.KeyValueMapper)"><code>flatMap()</code></a>). |
| If you choose not to attach one, this operation is similar to the stateless <a href="#flatMap(org.apache.kafka.streams.kstream.KeyValueMapper)"><code>flatMap()</code></a> |
| but allows access to the <code>ProcessorContext</code> and record metadata. |
| Furthermore, via <a href="../processor/Punctuator.html#punctuate(long)"><code>Punctuator#punctuate()</code></a> |
| the processing progress can be observed and additional periodic actions can be performed. |
| <p> |
| In order for the transformer to use state stores, the stores must be added to the topology and connected to the |
| transformer using at least one of two strategies (though it's not required to connect global state stores; read-only |
| access to global state stores is available by default). |
| <p> |
| The first strategy is to manually add the <a href="../state/StoreBuilder.html" title="interface in org.apache.kafka.streams.state"><code>StoreBuilder</code></a>s via <a href="../Topology.html#addStateStore(org.apache.kafka.streams.state.StoreBuilder,java.lang.String...)"><code>Topology.addStateStore(StoreBuilder, String...)</code></a>, |
| and specify the store names via <code>stateStoreNames</code> so they will be connected to the transformer. |
| <pre><code> |
| // create store |
| StoreBuilder<KeyValueStore<String,String>> keyValueStoreBuilder = |
| Stores.keyValueStoreBuilder(Stores.persistentKeyValueStore("myTransformState"), |
| Serdes.String(), |
| Serdes.String()); |
| // add store |
| builder.addStateStore(keyValueStoreBuilder); |
| |
| KStream outputStream = inputStream.transform(new TransformerSupplier() { |
| public Transformer get() { |
| return new MyTransformer(); |
| } |
| }, "myTransformState"); |
| </code></pre> |
| The second strategy is for the given <a href="TransformerSupplier.html" title="interface in org.apache.kafka.streams.kstream"><code>TransformerSupplier</code></a> to implement <a href="../processor/ConnectedStoreProvider.html#stores()"><code>ConnectedStoreProvider.stores()</code></a>, |
| which provides the <a href="../state/StoreBuilder.html" title="interface in org.apache.kafka.streams.state"><code>StoreBuilder</code></a>s to be automatically added to the topology and connected to the transformer. |
| <pre><code> |
| class MyTransformerSupplier implements TransformerSupplier { |
| // supply transformer |
| Transformer get() { |
| return new MyTransformer(); |
| } |
| |
| // provide store(s) that will be added and connected to the associated transformer |
| // the store name from the builder ("myTransformState") is used to access the store later via the ProcessorContext |
| Set<StoreBuilder> stores() { |
| StoreBuilder<KeyValueStore<String, String>> keyValueStoreBuilder = |
| Stores.keyValueStoreBuilder(Stores.persistentKeyValueStore("myTransformState"), |
| Serdes.String(), |
| Serdes.String()); |
| return Collections.singleton(keyValueStoreBuilder); |
| } |
| } |
| |
| ... |
| |
| KStream outputStream = inputStream.flatTransform(new MyTransformerSupplier()); |
| </code></pre> |
| <p> |
| With either strategy, within the <a href="Transformer.html" title="interface in org.apache.kafka.streams.kstream"><code>Transformer</code></a>, the state is obtained via the <a href="../processor/api/ProcessorContext.html" title="interface in org.apache.kafka.streams.processor.api"><code>ProcessorContext</code></a>. |
| To trigger periodic actions via <a href="../processor/Punctuator.html#punctuate(long)"><code>punctuate()</code></a>, |
| a schedule must be registered. |
| The <a href="Transformer.html" title="interface in org.apache.kafka.streams.kstream"><code>Transformer</code></a> must return an <a href="https://docs.oracle.com/en/java/javase/17/docs/api/java.base/java/lang/Iterable.html" title="class or interface in java.lang" class="external-link"><code>Iterable</code></a> type (e.g., any <a href="https://docs.oracle.com/en/java/javase/17/docs/api/java.base/java/util/Collection.html" title="class or interface in java.util" class="external-link"><code>Collection</code></a> |
| type) in <a href="Transformer.html#transform(K,V)"><code>transform()</code></a>. |
| The return value of <a href="Transformer.html#transform(K,V)"><code>Transformer#transform()</code></a> may be <code>null</code>, |
| which is equal to returning an empty <a href="https://docs.oracle.com/en/java/javase/17/docs/api/java.base/java/lang/Iterable.html" title="class or interface in java.lang" class="external-link"><code>Iterable</code></a>, i.e., no records are emitted. |
| <pre><code> |
| class MyTransformer implements Transformer { |
| private ProcessorContext context; |
| private StateStore state; |
| |
| void init(ProcessorContext context) { |
| this.context = context; |
| this.state = context.getStateStore("myTransformState"); |
| // punctuate each second; can access this.state |
| context.schedule(Duration.ofSeconds(1), PunctuationType.WALL_CLOCK_TIME, new Punctuator(..)); |
| } |
| |
| Iterable<KeyValue> transform(K key, V value) { |
| // can access this.state |
| List<KeyValue> result = new ArrayList<>(); |
| for (int i = 0; i < 3; i++) { |
| result.add(new KeyValue(key, value)); |
| } |
| return result; // emits a list of key-value pairs via return |
| } |
| |
| void close() { |
| // can access this.state |
| } |
| } |
| </code></pre> |
| Even if any upstream operation was key-changing, no auto-repartition is triggered. |
| If repartitioning is required, a call to <a href="#repartition()"><code>repartition()</code></a> should be performed before |
| <code>flatTransform()</code>. |
| <p> |
| Transforming records might result in an internal data redistribution if a key based operator (like an aggregation |
| or join) is applied to the result <code>KStream</code>. |
| (cf. <a href="#transformValues(org.apache.kafka.streams.kstream.ValueTransformerSupplier,java.lang.String...)"><code>transformValues()</code></a>) |
| <p> |
| Note that it is possible to emit records by using |
| <a href="../processor/ProcessorContext.html#forward(K,V)"><code>context#forward()</code></a> in <a href="Transformer.html#transform(K,V)"><code>Transformer#transform()</code></a> and |
| <a href="../processor/Punctuator.html#punctuate(long)"><code>Punctuator#punctuate()</code></a>. |
| Be aware that a mismatch between the types of the emitted records and the type of the stream would only be |
| detected at runtime. |
| To ensure type-safety at compile-time, |
| <a href="../processor/ProcessorContext.html#forward(K,V)"><code>context#forward()</code></a> should |
| not be used in <a href="Transformer.html#transform(K,V)"><code>Transformer#transform()</code></a> and |
| <a href="../processor/Punctuator.html#punctuate(long)"><code>Punctuator#punctuate()</code></a>. |
| The supplier should always generate a new instance each time <a href="TransformerSupplier.html#get()"><code>TransformerSupplier.get()</code></a> gets called. Creating |
| a single <a href="Transformer.html" title="interface in org.apache.kafka.streams.kstream"><code>Transformer</code></a> object and returning the same object reference in <a href="TransformerSupplier.html#get()"><code>TransformerSupplier.get()</code></a> would be |
| a violation of the supplier pattern and leads to runtime exceptions.</div> |
| <dl class="notes"> |
| <dt>Type Parameters:</dt> |
| <dd><code>K1</code> - the key type of the new stream</dd> |
| <dd><code>V1</code> - the value type of the new stream</dd> |
| <dt>Parameters:</dt> |
| <dd><code>transformerSupplier</code> - an instance of <a href="TransformerSupplier.html" title="interface in org.apache.kafka.streams.kstream"><code>TransformerSupplier</code></a> that generates a newly constructed <a href="Transformer.html" title="interface in org.apache.kafka.streams.kstream"><code>Transformer</code></a></dd> |
| <dd><code>stateStoreNames</code> - the names of the state stores used by the processor; not required if the supplier |
| implements <a href="../processor/ConnectedStoreProvider.html#stores()"><code>ConnectedStoreProvider.stores()</code></a></dd> |
| <dt>Returns:</dt> |
| <dd>a <code>KStream</code> that contains more or less records with new key and value (possibly of different type)</dd> |
| <dt>See Also:</dt> |
| <dd> |
| <ul class="see-list-long"> |
| <li><a href="#flatMap(org.apache.kafka.streams.kstream.KeyValueMapper)"><code>flatMap(KeyValueMapper)</code></a></li> |
| <li><a href="#transform(org.apache.kafka.streams.kstream.TransformerSupplier,java.lang.String...)"><code>transform(TransformerSupplier, String...)</code></a></li> |
| <li><a href="#transformValues(org.apache.kafka.streams.kstream.ValueTransformerSupplier,java.lang.String...)"><code>transformValues(ValueTransformerSupplier, String...)</code></a></li> |
| <li><a href="#transformValues(org.apache.kafka.streams.kstream.ValueTransformerWithKeySupplier,java.lang.String...)"><code>transformValues(ValueTransformerWithKeySupplier, String...)</code></a></li> |
| <li><a href="#process(org.apache.kafka.streams.processor.api.ProcessorSupplier,java.lang.String...)"><code>process(ProcessorSupplier, String...)</code></a></li> |
| </ul> |
| </dd> |
| </dl> |
| </section> |
| </li> |
| <li> |
| <section class="detail" id="flatTransform(org.apache.kafka.streams.kstream.TransformerSupplier,org.apache.kafka.streams.kstream.Named,java.lang.String...)"> |
| <h3>flatTransform</h3> |
| <div class="member-signature"><span class="type-parameters"><K1,<wbr> |
| V1></span> <span class="return-type"><a href="KStream.html" title="interface in org.apache.kafka.streams.kstream">KStream</a><K1,<wbr>V1></span> <span class="element-name">flatTransform</span><wbr><span class="parameters">(<a href="TransformerSupplier.html" title="interface in org.apache.kafka.streams.kstream">TransformerSupplier</a><? super <a href="KStream.html" title="type parameter in KStream">K</a>,<wbr>? super <a href="KStream.html" title="type parameter in KStream">V</a>,<wbr><a href="https://docs.oracle.com/en/java/javase/17/docs/api/java.base/java/lang/Iterable.html" title="class or interface in java.lang" class="external-link">Iterable</a><<a href="../KeyValue.html" title="class in org.apache.kafka.streams">KeyValue</a><K1,<wbr>V1>>> transformerSupplier, |
| <a href="Named.html" title="class in org.apache.kafka.streams.kstream">Named</a> named, |
| <a href="https://docs.oracle.com/en/java/javase/17/docs/api/java.base/java/lang/String.html" title="class or interface in java.lang" class="external-link">String</a>... stateStoreNames)</span></div> |
| <div class="block">Transform each record of the input stream into zero or more records in the output stream (both key and value type |
| can be altered arbitrarily). |
| A <a href="Transformer.html" title="interface in org.apache.kafka.streams.kstream"><code>Transformer</code></a> (provided by the given <a href="TransformerSupplier.html" title="interface in org.apache.kafka.streams.kstream"><code>TransformerSupplier</code></a>) is applied to each input record and |
| returns zero or more output records. |
| Thus, an input record <code><K,V></code> can be transformed into output records <code><K':V'>, <K'':V''>, ...</code>. |
| Attaching a state store makes this a stateful record-by-record operation (cf. <a href="#flatMap(org.apache.kafka.streams.kstream.KeyValueMapper)"><code>flatMap()</code></a>). |
| If you choose not to attach one, this operation is similar to the stateless <a href="#flatMap(org.apache.kafka.streams.kstream.KeyValueMapper)"><code>flatMap()</code></a> |
| but allows access to the <code>ProcessorContext</code> and record metadata. |
| Furthermore, via <a href="../processor/Punctuator.html#punctuate(long)"><code>Punctuator#punctuate()</code></a> |
| the processing progress can be observed and additional periodic actions can be performed. |
| <p> |
| In order for the transformer to use state stores, the stores must be added to the topology and connected to the |
| transformer using at least one of two strategies (though it's not required to connect global state stores; read-only |
| access to global state stores is available by default). |
| <p> |
| The first strategy is to manually add the <a href="../state/StoreBuilder.html" title="interface in org.apache.kafka.streams.state"><code>StoreBuilder</code></a>s via <a href="../Topology.html#addStateStore(org.apache.kafka.streams.state.StoreBuilder,java.lang.String...)"><code>Topology.addStateStore(StoreBuilder, String...)</code></a>, |
| and specify the store names via <code>stateStoreNames</code> so they will be connected to the transformer. |
| <pre><code> |
| // create store |
| StoreBuilder<KeyValueStore<String,String>> keyValueStoreBuilder = |
| Stores.keyValueStoreBuilder(Stores.persistentKeyValueStore("myTransformState"), |
| Serdes.String(), |
| Serdes.String()); |
| // add store |
| builder.addStateStore(keyValueStoreBuilder); |
| |
| KStream outputStream = inputStream.transform(new TransformerSupplier() { |
| public Transformer get() { |
| return new MyTransformer(); |
| } |
| }, "myTransformState"); |
| </code></pre> |
| The second strategy is for the given <a href="TransformerSupplier.html" title="interface in org.apache.kafka.streams.kstream"><code>TransformerSupplier</code></a> to implement <a href="../processor/ConnectedStoreProvider.html#stores()"><code>ConnectedStoreProvider.stores()</code></a>, |
| which provides the <a href="../state/StoreBuilder.html" title="interface in org.apache.kafka.streams.state"><code>StoreBuilder</code></a>s to be automatically added to the topology and connected to the transformer. |
| <pre><code> |
| class MyTransformerSupplier implements TransformerSupplier { |
| // supply transformer |
| Transformer get() { |
| return new MyTransformer(); |
| } |
| |
| // provide store(s) that will be added and connected to the associated transformer |
| // the store name from the builder ("myTransformState") is used to access the store later via the ProcessorContext |
| Set<StoreBuilder> stores() { |
| StoreBuilder<KeyValueStore<String, String>> keyValueStoreBuilder = |
| Stores.keyValueStoreBuilder(Stores.persistentKeyValueStore("myTransformState"), |
| Serdes.String(), |
| Serdes.String()); |
| return Collections.singleton(keyValueStoreBuilder); |
| } |
| } |
| |
| ... |
| |
| KStream outputStream = inputStream.flatTransform(new MyTransformerSupplier()); |
| </code></pre> |
| <p> |
| With either strategy, within the <a href="Transformer.html" title="interface in org.apache.kafka.streams.kstream"><code>Transformer</code></a>, the state is obtained via the <a href="../processor/api/ProcessorContext.html" title="interface in org.apache.kafka.streams.processor.api"><code>ProcessorContext</code></a>. |
| To trigger periodic actions via <a href="../processor/Punctuator.html#punctuate(long)"><code>punctuate()</code></a>, |
| a schedule must be registered. |
| The <a href="Transformer.html" title="interface in org.apache.kafka.streams.kstream"><code>Transformer</code></a> must return an <a href="https://docs.oracle.com/en/java/javase/17/docs/api/java.base/java/lang/Iterable.html" title="class or interface in java.lang" class="external-link"><code>Iterable</code></a> type (e.g., any <a href="https://docs.oracle.com/en/java/javase/17/docs/api/java.base/java/util/Collection.html" title="class or interface in java.util" class="external-link"><code>Collection</code></a> |
| type) in <a href="Transformer.html#transform(K,V)"><code>transform()</code></a>. |
| The return value of <a href="Transformer.html#transform(K,V)"><code>Transformer#transform()</code></a> may be <code>null</code>, |
| which is equal to returning an empty <a href="https://docs.oracle.com/en/java/javase/17/docs/api/java.base/java/lang/Iterable.html" title="class or interface in java.lang" class="external-link"><code>Iterable</code></a>, i.e., no records are emitted. |
| <pre><code> |
| class MyTransformer implements Transformer { |
| private ProcessorContext context; |
| private StateStore state; |
| |
| void init(ProcessorContext context) { |
| this.context = context; |
| this.state = context.getStateStore("myTransformState"); |
| // punctuate each second; can access this.state |
| context.schedule(Duration.ofSeconds(1), PunctuationType.WALL_CLOCK_TIME, new Punctuator(..)); |
| } |
| |
| Iterable<KeyValue> transform(K key, V value) { |
| // can access this.state |
| List<KeyValue> result = new ArrayList<>(); |
| for (int i = 0; i < 3; i++) { |
| result.add(new KeyValue(key, value)); |
| } |
| return result; // emits a list of key-value pairs via return |
| } |
| |
| void close() { |
| // can access this.state |
| } |
| } |
| </code></pre> |
| Even if any upstream operation was key-changing, no auto-repartition is triggered. |
| If repartitioning is required, a call to <a href="#repartition()"><code>repartition()</code></a> should be performed before |
| <code>flatTransform()</code>. |
| <p> |
| Transforming records might result in an internal data redistribution if a key based operator (like an aggregation |
| or join) is applied to the result <code>KStream</code>. |
| (cf. <a href="#transformValues(org.apache.kafka.streams.kstream.ValueTransformerSupplier,java.lang.String...)"><code>transformValues()</code></a>) |
| <p> |
| Note that it is possible to emit records by using |
| <a href="../processor/ProcessorContext.html#forward(K,V)"><code>context#forward()</code></a> in <a href="Transformer.html#transform(K,V)"><code>Transformer#transform()</code></a> and |
| <a href="../processor/Punctuator.html#punctuate(long)"><code>Punctuator#punctuate()</code></a>. |
| Be aware that a mismatch between the types of the emitted records and the type of the stream would only be |
| detected at runtime. |
| To ensure type-safety at compile-time, |
| <a href="../processor/ProcessorContext.html#forward(K,V)"><code>context#forward()</code></a> should |
| not be used in <a href="Transformer.html#transform(K,V)"><code>Transformer#transform()</code></a> and |
| <a href="../processor/Punctuator.html#punctuate(long)"><code>Punctuator#punctuate()</code></a>. |
| The supplier should always generate a new instance each time <a href="TransformerSupplier.html#get()"><code>TransformerSupplier.get()</code></a> gets called. Creating |
| a single <a href="Transformer.html" title="interface in org.apache.kafka.streams.kstream"><code>Transformer</code></a> object and returning the same object reference in <a href="TransformerSupplier.html#get()"><code>TransformerSupplier.get()</code></a> would be |
| a violation of the supplier pattern and leads to runtime exceptions.</div> |
| <dl class="notes"> |
| <dt>Type Parameters:</dt> |
| <dd><code>K1</code> - the key type of the new stream</dd> |
| <dd><code>V1</code> - the value type of the new stream</dd> |
| <dt>Parameters:</dt> |
| <dd><code>transformerSupplier</code> - an instance of <a href="TransformerSupplier.html" title="interface in org.apache.kafka.streams.kstream"><code>TransformerSupplier</code></a> that generates a newly constructed <a href="Transformer.html" title="interface in org.apache.kafka.streams.kstream"><code>Transformer</code></a></dd> |
| <dd><code>named</code> - a <a href="Named.html" title="class in org.apache.kafka.streams.kstream"><code>Named</code></a> config used to name the processor in the topology</dd> |
| <dd><code>stateStoreNames</code> - the names of the state stores used by the processor; not required if the supplier |
| implements <a href="../processor/ConnectedStoreProvider.html#stores()"><code>ConnectedStoreProvider.stores()</code></a></dd> |
| <dt>Returns:</dt> |
| <dd>a <code>KStream</code> that contains more or less records with new key and value (possibly of different type)</dd> |
| <dt>See Also:</dt> |
| <dd> |
| <ul class="see-list-long"> |
| <li><a href="#flatMap(org.apache.kafka.streams.kstream.KeyValueMapper)"><code>flatMap(KeyValueMapper)</code></a></li> |
| <li><a href="#transform(org.apache.kafka.streams.kstream.TransformerSupplier,java.lang.String...)"><code>transform(TransformerSupplier, String...)</code></a></li> |
| <li><a href="#transformValues(org.apache.kafka.streams.kstream.ValueTransformerSupplier,java.lang.String...)"><code>transformValues(ValueTransformerSupplier, String...)</code></a></li> |
| <li><a href="#transformValues(org.apache.kafka.streams.kstream.ValueTransformerWithKeySupplier,java.lang.String...)"><code>transformValues(ValueTransformerWithKeySupplier, String...)</code></a></li> |
| <li><a href="#process(org.apache.kafka.streams.processor.api.ProcessorSupplier,java.lang.String...)"><code>process(ProcessorSupplier, String...)</code></a></li> |
| </ul> |
| </dd> |
| </dl> |
| </section> |
| </li> |
| <li> |
| <section class="detail" id="transformValues(org.apache.kafka.streams.kstream.ValueTransformerSupplier,java.lang.String...)"> |
| <h3>transformValues</h3> |
| <div class="member-signature"><span class="type-parameters"><VR></span> <span class="return-type"><a href="KStream.html" title="interface in org.apache.kafka.streams.kstream">KStream</a><<a href="KStream.html" title="type parameter in KStream">K</a>,<wbr>VR></span> <span class="element-name">transformValues</span><wbr><span class="parameters">(<a href="ValueTransformerSupplier.html" title="interface in org.apache.kafka.streams.kstream">ValueTransformerSupplier</a><? super <a href="KStream.html" title="type parameter in KStream">V</a>,<wbr>? extends VR> valueTransformerSupplier, |
| <a href="https://docs.oracle.com/en/java/javase/17/docs/api/java.base/java/lang/String.html" title="class or interface in java.lang" class="external-link">String</a>... stateStoreNames)</span></div> |
| <div class="block">Transform the value of each input record into a new value (with possibly a new type) of the output record. |
| A <a href="ValueTransformer.html" title="interface in org.apache.kafka.streams.kstream"><code>ValueTransformer</code></a> (provided by the given <a href="ValueTransformerSupplier.html" title="interface in org.apache.kafka.streams.kstream"><code>ValueTransformerSupplier</code></a>) is applied to each input |
| record value and computes a new value for it. |
| Thus, an input record <code><K,V></code> can be transformed into an output record <code><K:V'></code>. |
| Attaching a state store makes this a stateful record-by-record operation (cf. <a href="#mapValues(org.apache.kafka.streams.kstream.ValueMapper)"><code>mapValues()</code></a>). |
| If you choose not to attach one, this operation is similar to the stateless <a href="#mapValues(org.apache.kafka.streams.kstream.ValueMapper)"><code>mapValues()</code></a> |
| but allows access to the <code>ProcessorContext</code> and record metadata. |
| Furthermore, via <a href="../processor/Punctuator.html#punctuate(long)"><code>Punctuator.punctuate(long)</code></a> the processing progress |
| can be observed and additional periodic actions can be performed. |
| <p> |
| In order for the transformer to use state stores, the stores must be added to the topology and connected to the |
| transformer using at least one of two strategies (though it's not required to connect global state stores; read-only |
| access to global state stores is available by default). |
| <p> |
| The first strategy is to manually add the <a href="../state/StoreBuilder.html" title="interface in org.apache.kafka.streams.state"><code>StoreBuilder</code></a>s via <a href="../Topology.html#addStateStore(org.apache.kafka.streams.state.StoreBuilder,java.lang.String...)"><code>Topology.addStateStore(StoreBuilder, String...)</code></a>, |
| and specify the store names via <code>stateStoreNames</code> so they will be connected to the transformer. |
| <pre><code> |
| // create store |
| StoreBuilder<KeyValueStore<String,String>> keyValueStoreBuilder = |
| Stores.keyValueStoreBuilder(Stores.persistentKeyValueStore("myValueTransformState"), |
| Serdes.String(), |
| Serdes.String()); |
| // add store |
| builder.addStateStore(keyValueStoreBuilder); |
| |
| KStream outputStream = inputStream.transformValues(new ValueTransformerSupplier() { |
| public ValueTransformer get() { |
| return new MyValueTransformer(); |
| } |
| }, "myValueTransformState"); |
| </code></pre> |
| The second strategy is for the given <a href="ValueTransformerSupplier.html" title="interface in org.apache.kafka.streams.kstream"><code>ValueTransformerSupplier</code></a> to implement <a href="../processor/ConnectedStoreProvider.html#stores()"><code>ConnectedStoreProvider.stores()</code></a>, |
| which provides the <a href="../state/StoreBuilder.html" title="interface in org.apache.kafka.streams.state"><code>StoreBuilder</code></a>s to be automatically added to the topology and connected to the transformer. |
| <pre><code> |
| class MyValueTransformerSupplier implements ValueTransformerSupplier { |
| // supply transformer |
| ValueTransformer get() { |
| return new MyValueTransformer(); |
| } |
| |
| // provide store(s) that will be added and connected to the associated transformer |
| // the store name from the builder ("myValueTransformState") is used to access the store later via the ProcessorContext |
| Set<StoreBuilder> stores() { |
| StoreBuilder<KeyValueStore<String, String>> keyValueStoreBuilder = |
| Stores.keyValueStoreBuilder(Stores.persistentKeyValueStore("myValueTransformState"), |
| Serdes.String(), |
| Serdes.String()); |
| return Collections.singleton(keyValueStoreBuilder); |
| } |
| } |
| |
| ... |
| |
| KStream outputStream = inputStream.transformValues(new MyValueTransformerSupplier()); |
| </code></pre> |
| <p> |
| With either strategy, within the <a href="ValueTransformer.html" title="interface in org.apache.kafka.streams.kstream"><code>ValueTransformer</code></a>, the state is obtained via the <a href="../processor/api/ProcessorContext.html" title="interface in org.apache.kafka.streams.processor.api"><code>ProcessorContext</code></a>. |
| To trigger periodic actions via <a href="../processor/Punctuator.html#punctuate(long)"><code>punctuate()</code></a>, |
| a schedule must be registered. |
| The <a href="ValueTransformer.html" title="interface in org.apache.kafka.streams.kstream"><code>ValueTransformer</code></a> must return the new value in <a href="ValueTransformer.html#transform(V)"><code>transform()</code></a>. |
| In contrast to <a href="#transform(org.apache.kafka.streams.kstream.TransformerSupplier,java.lang.String...)"><code>transform()</code></a>, no additional <a href="../KeyValue.html" title="class in org.apache.kafka.streams"><code>KeyValue</code></a> |
| pairs can be emitted via |
| <a href="../processor/ProcessorContext.html#forward(K,V)"><code>ProcessorContext.forward()</code></a>. |
| A <a href="../errors/StreamsException.html" title="class in org.apache.kafka.streams.errors"><code>StreamsException</code></a> is thrown if the <a href="ValueTransformer.html" title="interface in org.apache.kafka.streams.kstream"><code>ValueTransformer</code></a> tries to |
| emit a <a href="../KeyValue.html" title="class in org.apache.kafka.streams"><code>KeyValue</code></a> pair. |
| <pre><code> |
| class MyValueTransformer implements ValueTransformer { |
| private StateStore state; |
| |
| void init(ProcessorContext context) { |
| this.state = context.getStateStore("myValueTransformState"); |
| // punctuate each second, can access this.state |
| context.schedule(Duration.ofSeconds(1), PunctuationType.WALL_CLOCK_TIME, new Punctuator(..)); |
| } |
| |
| NewValueType transform(V value) { |
| // can access this.state |
| return new NewValueType(); // or null |
| } |
| |
| void close() { |
| // can access this.state |
| } |
| } |
| </code></pre> |
| Even if any upstream operation was key-changing, no auto-repartition is triggered. |
| If repartitioning is required, a call to <a href="#repartition()"><code>repartition()</code></a> should be performed before |
| <code>transformValues()</code>. |
| <p> |
| Setting a new value preserves data co-location with respect to the key. |
| Thus, <em>no</em> internal data redistribution is required if a key based operator (like an aggregation or join) |
| is applied to the result <code>KStream</code>. (cf. <a href="#transform(org.apache.kafka.streams.kstream.TransformerSupplier,java.lang.String...)"><code>transform(TransformerSupplier, String...)</code></a>)</div> |
| <dl class="notes"> |
| <dt>Type Parameters:</dt> |
| <dd><code>VR</code> - the value type of the result stream</dd> |
| <dt>Parameters:</dt> |
| <dd><code>valueTransformerSupplier</code> - an instance of <a href="ValueTransformerSupplier.html" title="interface in org.apache.kafka.streams.kstream"><code>ValueTransformerSupplier</code></a> that generates a newly constructed <a href="ValueTransformer.html" title="interface in org.apache.kafka.streams.kstream"><code>ValueTransformer</code></a> |
| The supplier should always generate a new instance. Creating a single <a href="ValueTransformer.html" title="interface in org.apache.kafka.streams.kstream"><code>ValueTransformer</code></a> object |
| and returning the same object reference in <a href="ValueTransformer.html" title="interface in org.apache.kafka.streams.kstream"><code>ValueTransformer</code></a> is a |
| violation of the supplier pattern and leads to runtime exceptions.</dd> |
| <dd><code>stateStoreNames</code> - the names of the state stores used by the processor; not required if the supplier |
| implements <a href="../processor/ConnectedStoreProvider.html#stores()"><code>ConnectedStoreProvider.stores()</code></a></dd> |
| <dt>Returns:</dt> |
| <dd>a <code>KStream</code> that contains records with unmodified key and new values (possibly of different type)</dd> |
| <dt>See Also:</dt> |
| <dd> |
| <ul class="see-list-long"> |
| <li><a href="#mapValues(org.apache.kafka.streams.kstream.ValueMapper)"><code>mapValues(ValueMapper)</code></a></li> |
| <li><a href="#mapValues(org.apache.kafka.streams.kstream.ValueMapperWithKey)"><code>mapValues(ValueMapperWithKey)</code></a></li> |
| <li><a href="#transform(org.apache.kafka.streams.kstream.TransformerSupplier,java.lang.String...)"><code>transform(TransformerSupplier, String...)</code></a></li> |
| </ul> |
| </dd> |
| </dl> |
| </section> |
| </li> |
| <li> |
| <section class="detail" id="transformValues(org.apache.kafka.streams.kstream.ValueTransformerSupplier,org.apache.kafka.streams.kstream.Named,java.lang.String...)"> |
| <h3>transformValues</h3> |
| <div class="member-signature"><span class="type-parameters"><VR></span> <span class="return-type"><a href="KStream.html" title="interface in org.apache.kafka.streams.kstream">KStream</a><<a href="KStream.html" title="type parameter in KStream">K</a>,<wbr>VR></span> <span class="element-name">transformValues</span><wbr><span class="parameters">(<a href="ValueTransformerSupplier.html" title="interface in org.apache.kafka.streams.kstream">ValueTransformerSupplier</a><? super <a href="KStream.html" title="type parameter in KStream">V</a>,<wbr>? extends VR> valueTransformerSupplier, |
| <a href="Named.html" title="class in org.apache.kafka.streams.kstream">Named</a> named, |
| <a href="https://docs.oracle.com/en/java/javase/17/docs/api/java.base/java/lang/String.html" title="class or interface in java.lang" class="external-link">String</a>... stateStoreNames)</span></div> |
| <div class="block">Transform the value of each input record into a new value (with possibly a new type) of the output record. |
| A <a href="ValueTransformer.html" title="interface in org.apache.kafka.streams.kstream"><code>ValueTransformer</code></a> (provided by the given <a href="ValueTransformerSupplier.html" title="interface in org.apache.kafka.streams.kstream"><code>ValueTransformerSupplier</code></a>) is applied to each input |
| record value and computes a new value for it. |
| Thus, an input record <code><K,V></code> can be transformed into an output record <code><K:V'></code>. |
| Attaching a state store makes this a stateful record-by-record operation (cf. <a href="#mapValues(org.apache.kafka.streams.kstream.ValueMapper)"><code>mapValues()</code></a>). |
| If you choose not to attach one, this operation is similar to the stateless <a href="#mapValues(org.apache.kafka.streams.kstream.ValueMapper)"><code>mapValues()</code></a> |
| but allows access to the <code>ProcessorContext</code> and record metadata. |
| This is essentially mixing the Processor API into the DSL, and provides all the functionality of the PAPI. |
| Furthermore, via <a href="../processor/Punctuator.html#punctuate(long)"><code>Punctuator.punctuate(long)</code></a> the processing progress |
| can be observed and additional periodic actions can be performed. |
| <p> |
| In order for the transformer to use state stores, the stores must be added to the topology and connected to the |
| transformer using at least one of two strategies (though it's not required to connect global state stores; read-only |
| access to global state stores is available by default). |
| <p> |
| The first strategy is to manually add the <a href="../state/StoreBuilder.html" title="interface in org.apache.kafka.streams.state"><code>StoreBuilder</code></a>s via <a href="../Topology.html#addStateStore(org.apache.kafka.streams.state.StoreBuilder,java.lang.String...)"><code>Topology.addStateStore(StoreBuilder, String...)</code></a>, |
| and specify the store names via <code>stateStoreNames</code> so they will be connected to the transformer. |
| <pre><code> |
| // create store |
| StoreBuilder<KeyValueStore<String,String>> keyValueStoreBuilder = |
| Stores.keyValueStoreBuilder(Stores.persistentKeyValueStore("myValueTransformState"), |
| Serdes.String(), |
| Serdes.String()); |
| // add store |
| builder.addStateStore(keyValueStoreBuilder); |
| |
| KStream outputStream = inputStream.transformValues(new ValueTransformerSupplier() { |
| public ValueTransformer get() { |
| return new MyValueTransformer(); |
| } |
| }, "myValueTransformState"); |
| </code></pre> |
| The second strategy is for the given <a href="ValueTransformerSupplier.html" title="interface in org.apache.kafka.streams.kstream"><code>ValueTransformerSupplier</code></a> to implement <a href="../processor/ConnectedStoreProvider.html#stores()"><code>ConnectedStoreProvider.stores()</code></a>, |
| which provides the <a href="../state/StoreBuilder.html" title="interface in org.apache.kafka.streams.state"><code>StoreBuilder</code></a>s to be automatically added to the topology and connected to the transformer. |
| <pre><code> |
| class MyValueTransformerSupplier implements ValueTransformerSupplier { |
| // supply transformer |
| ValueTransformer get() { |
| return new MyValueTransformer(); |
| } |
| |
| // provide store(s) that will be added and connected to the associated transformer |
| // the store name from the builder ("myValueTransformState") is used to access the store later via the ProcessorContext |
| Set<StoreBuilder> stores() { |
| StoreBuilder<KeyValueStore<String, String>> keyValueStoreBuilder = |
| Stores.keyValueStoreBuilder(Stores.persistentKeyValueStore("myValueTransformState"), |
| Serdes.String(), |
| Serdes.String()); |
| return Collections.singleton(keyValueStoreBuilder); |
| } |
| } |
| |
| ... |
| |
| KStream outputStream = inputStream.transformValues(new MyValueTransformerSupplier()); |
| </code></pre> |
| <p> |
| With either strategy, within the <a href="ValueTransformer.html" title="interface in org.apache.kafka.streams.kstream"><code>ValueTransformer</code></a>, the state is obtained via the <a href="../processor/api/ProcessorContext.html" title="interface in org.apache.kafka.streams.processor.api"><code>ProcessorContext</code></a>. |
| To trigger periodic actions via <a href="../processor/Punctuator.html#punctuate(long)"><code>punctuate()</code></a>, |
| a schedule must be registered. |
| The <a href="ValueTransformer.html" title="interface in org.apache.kafka.streams.kstream"><code>ValueTransformer</code></a> must return the new value in <a href="ValueTransformer.html#transform(V)"><code>transform()</code></a>. |
| In contrast to <a href="#transform(org.apache.kafka.streams.kstream.TransformerSupplier,java.lang.String...)"><code>transform()</code></a>, no additional <a href="../KeyValue.html" title="class in org.apache.kafka.streams"><code>KeyValue</code></a> |
| pairs can be emitted via |
| <a href="../processor/ProcessorContext.html#forward(K,V)"><code>ProcessorContext.forward()</code></a>. |
| A <a href="../errors/StreamsException.html" title="class in org.apache.kafka.streams.errors"><code>StreamsException</code></a> is thrown if the <a href="ValueTransformer.html" title="interface in org.apache.kafka.streams.kstream"><code>ValueTransformer</code></a> tries to |
| emit a <a href="../KeyValue.html" title="class in org.apache.kafka.streams"><code>KeyValue</code></a> pair. |
| <pre><code> |
| class MyValueTransformer implements ValueTransformer { |
| private StateStore state; |
| |
| void init(ProcessorContext context) { |
| this.state = context.getStateStore("myValueTransformState"); |
| // punctuate each second, can access this.state |
| context.schedule(Duration.ofSeconds(1), PunctuationType.WALL_CLOCK_TIME, new Punctuator(..)); |
| } |
| |
| NewValueType transform(V value) { |
| // can access this.state |
| return new NewValueType(); // or null |
| } |
| |
| void close() { |
| // can access this.state |
| } |
| } |
| </code></pre> |
| Even if any upstream operation was key-changing, no auto-repartition is triggered. |
| If repartitioning is required, a call to <a href="#repartition()"><code>repartition()</code></a> should be performed before |
| <code>transformValues()</code>. |
| <p> |
| Setting a new value preserves data co-location with respect to the key. |
| Thus, <em>no</em> internal data redistribution is required if a key based operator (like an aggregation or join) |
| is applied to the result <code>KStream</code>. (cf. <a href="#transform(org.apache.kafka.streams.kstream.TransformerSupplier,java.lang.String...)"><code>transform(TransformerSupplier, String...)</code></a>)</div> |
| <dl class="notes"> |
| <dt>Type Parameters:</dt> |
| <dd><code>VR</code> - the value type of the result stream</dd> |
| <dt>Parameters:</dt> |
| <dd><code>valueTransformerSupplier</code> - an instance of <a href="ValueTransformerSupplier.html" title="interface in org.apache.kafka.streams.kstream"><code>ValueTransformerSupplier</code></a> that generates a newly constructed <a href="ValueTransformer.html" title="interface in org.apache.kafka.streams.kstream"><code>ValueTransformer</code></a> |
| The supplier should always generate a new instance. Creating a single <a href="ValueTransformer.html" title="interface in org.apache.kafka.streams.kstream"><code>ValueTransformer</code></a> object |
| and returning the same object reference in <a href="ValueTransformer.html" title="interface in org.apache.kafka.streams.kstream"><code>ValueTransformer</code></a> is a |
| violation of the supplier pattern and leads to runtime exceptions.</dd> |
| <dd><code>named</code> - a <a href="Named.html" title="class in org.apache.kafka.streams.kstream"><code>Named</code></a> config used to name the processor in the topology</dd> |
| <dd><code>stateStoreNames</code> - the names of the state stores used by the processor; not required if the supplier |
| implements <a href="../processor/ConnectedStoreProvider.html#stores()"><code>ConnectedStoreProvider.stores()</code></a></dd> |
| <dt>Returns:</dt> |
| <dd>a <code>KStream</code> that contains records with unmodified key and new values (possibly of different type)</dd> |
| <dt>See Also:</dt> |
| <dd> |
| <ul class="see-list-long"> |
| <li><a href="#mapValues(org.apache.kafka.streams.kstream.ValueMapper)"><code>mapValues(ValueMapper)</code></a></li> |
| <li><a href="#mapValues(org.apache.kafka.streams.kstream.ValueMapperWithKey)"><code>mapValues(ValueMapperWithKey)</code></a></li> |
| <li><a href="#transform(org.apache.kafka.streams.kstream.TransformerSupplier,java.lang.String...)"><code>transform(TransformerSupplier, String...)</code></a></li> |
| </ul> |
| </dd> |
| </dl> |
| </section> |
| </li> |
| <li> |
| <section class="detail" id="transformValues(org.apache.kafka.streams.kstream.ValueTransformerWithKeySupplier,java.lang.String...)"> |
| <h3>transformValues</h3> |
| <div class="member-signature"><span class="type-parameters"><VR></span> <span class="return-type"><a href="KStream.html" title="interface in org.apache.kafka.streams.kstream">KStream</a><<a href="KStream.html" title="type parameter in KStream">K</a>,<wbr>VR></span> <span class="element-name">transformValues</span><wbr><span class="parameters">(<a href="ValueTransformerWithKeySupplier.html" title="interface in org.apache.kafka.streams.kstream">ValueTransformerWithKeySupplier</a><? super <a href="KStream.html" title="type parameter in KStream">K</a>,<wbr>? super <a href="KStream.html" title="type parameter in KStream">V</a>,<wbr>? extends VR> valueTransformerSupplier, |
| <a href="https://docs.oracle.com/en/java/javase/17/docs/api/java.base/java/lang/String.html" title="class or interface in java.lang" class="external-link">String</a>... stateStoreNames)</span></div> |
| <div class="block">Transform the value of each input record into a new value (with possibly a new type) of the output record. |
| A <a href="ValueTransformerWithKey.html" title="interface in org.apache.kafka.streams.kstream"><code>ValueTransformerWithKey</code></a> (provided by the given <a href="ValueTransformerWithKeySupplier.html" title="interface in org.apache.kafka.streams.kstream"><code>ValueTransformerWithKeySupplier</code></a>) is applied to |
| each input record value and computes a new value for it. |
| Thus, an input record <code><K,V></code> can be transformed into an output record <code><K:V'></code>. |
| Attaching a state store makes this a stateful record-by-record operation (cf. <a href="#mapValues(org.apache.kafka.streams.kstream.ValueMapperWithKey)"><code>mapValues()</code></a>). |
| If you choose not to attach one, this operation is similar to the stateless <a href="#mapValues(org.apache.kafka.streams.kstream.ValueMapperWithKey)"><code>mapValues()</code></a> |
| but allows access to the <code>ProcessorContext</code> and record metadata. |
| This is essentially mixing the Processor API into the DSL, and provides all the functionality of the PAPI. |
| Furthermore, via <a href="../processor/Punctuator.html#punctuate(long)"><code>Punctuator.punctuate(long)</code></a> the processing progress |
| can be observed and additional periodic actions can be performed. |
| <p> |
| In order for the transformer to use state stores, the stores must be added to the topology and connected to the |
| transformer using at least one of two strategies (though it's not required to connect global state stores; read-only |
| access to global state stores is available by default). |
| <p> |
| The first strategy is to manually add the <a href="../state/StoreBuilder.html" title="interface in org.apache.kafka.streams.state"><code>StoreBuilder</code></a>s via <a href="../Topology.html#addStateStore(org.apache.kafka.streams.state.StoreBuilder,java.lang.String...)"><code>Topology.addStateStore(StoreBuilder, String...)</code></a>, |
| and specify the store names via <code>stateStoreNames</code> so they will be connected to the transformer. |
| <pre><code> |
| // create store |
| StoreBuilder<KeyValueStore<String,String>> keyValueStoreBuilder = |
| Stores.keyValueStoreBuilder(Stores.persistentKeyValueStore("myValueTransformState"), |
| Serdes.String(), |
| Serdes.String()); |
| // add store |
| builder.addStateStore(keyValueStoreBuilder); |
| |
| KStream outputStream = inputStream.transformValues(new ValueTransformerWithKeySupplier() { |
| public ValueTransformer get() { |
| return new MyValueTransformer(); |
| } |
| }, "myValueTransformState"); |
| </code></pre> |
| The second strategy is for the given <a href="ValueTransformerWithKeySupplier.html" title="interface in org.apache.kafka.streams.kstream"><code>ValueTransformerWithKeySupplier</code></a> to implement <a href="../processor/ConnectedStoreProvider.html#stores()"><code>ConnectedStoreProvider.stores()</code></a>, |
| which provides the <a href="../state/StoreBuilder.html" title="interface in org.apache.kafka.streams.state"><code>StoreBuilder</code></a>s to be automatically added to the topology and connected to the transformer. |
| <pre><code> |
| class MyValueTransformerWithKeySupplier implements ValueTransformerWithKeySupplier { |
| // supply transformer |
| ValueTransformerWithKey get() { |
| return new MyValueTransformerWithKey(); |
| } |
| |
| // provide store(s) that will be added and connected to the associated transformer |
| // the store name from the builder ("myValueTransformState") is used to access the store later via the ProcessorContext |
| Set<StoreBuilder> stores() { |
| StoreBuilder<KeyValueStore<String, String>> keyValueStoreBuilder = |
| Stores.keyValueStoreBuilder(Stores.persistentKeyValueStore("myValueTransformState"), |
| Serdes.String(), |
| Serdes.String()); |
| return Collections.singleton(keyValueStoreBuilder); |
| } |
| } |
| |
| ... |
| |
| KStream outputStream = inputStream.transformValues(new MyValueTransformerWithKeySupplier()); |
| </code></pre> |
| <p> |
| With either strategy, within the <a href="ValueTransformerWithKey.html" title="interface in org.apache.kafka.streams.kstream"><code>ValueTransformerWithKey</code></a>, the state is obtained via the <a href="../processor/api/ProcessorContext.html" title="interface in org.apache.kafka.streams.processor.api"><code>ProcessorContext</code></a>. |
| To trigger periodic actions via <a href="../processor/Punctuator.html#punctuate(long)"><code>punctuate()</code></a>, |
| a schedule must be registered. |
| The <a href="ValueTransformerWithKey.html" title="interface in org.apache.kafka.streams.kstream"><code>ValueTransformerWithKey</code></a> must return the new value in |
| <a href="ValueTransformerWithKey.html#transform(K,V)"><code>transform()</code></a>. |
| In contrast to <a href="#transform(org.apache.kafka.streams.kstream.TransformerSupplier,java.lang.String...)"><code>transform()</code></a> and |
| <a href="#flatTransform(org.apache.kafka.streams.kstream.TransformerSupplier,java.lang.String...)"><code>flatTransform()</code></a>, no additional <a href="../KeyValue.html" title="class in org.apache.kafka.streams"><code>KeyValue</code></a> pairs |
| can be emitted via |
| <a href="../processor/ProcessorContext.html#forward(K,V)"><code>ProcessorContext.forward()</code></a>. |
| A <a href="../errors/StreamsException.html" title="class in org.apache.kafka.streams.errors"><code>StreamsException</code></a> is thrown if the <a href="ValueTransformerWithKey.html" title="interface in org.apache.kafka.streams.kstream"><code>ValueTransformerWithKey</code></a> tries |
| to emit a <a href="../KeyValue.html" title="class in org.apache.kafka.streams"><code>KeyValue</code></a> pair. |
| <pre><code> |
| class MyValueTransformerWithKey implements ValueTransformerWithKey { |
| private StateStore state; |
| |
| void init(ProcessorContext context) { |
| this.state = context.getStateStore("myValueTransformState"); |
| // punctuate each second, can access this.state |
| context.schedule(Duration.ofSeconds(1), PunctuationType.WALL_CLOCK_TIME, new Punctuator(..)); |
| } |
| |
| NewValueType transform(K readOnlyKey, V value) { |
| // can access this.state and use read-only key |
| return new NewValueType(readOnlyKey); // or null |
| } |
| |
| void close() { |
| // can access this.state |
| } |
| } |
| </code></pre> |
| Even if any upstream operation was key-changing, no auto-repartition is triggered. |
| If repartitioning is required, a call to <a href="#repartition()"><code>repartition()</code></a> should be performed before |
| <code>transformValues()</code>. |
| <p> |
| Note that the key is read-only and should not be modified, as this can lead to corrupt partitioning. |
| So, setting a new value preserves data co-location with respect to the key. |
| Thus, <em>no</em> internal data redistribution is required if a key based operator (like an aggregation or join) |
| is applied to the result <code>KStream</code>. (cf. <a href="#transform(org.apache.kafka.streams.kstream.TransformerSupplier,java.lang.String...)"><code>transform(TransformerSupplier, String...)</code></a>)</div> |
| <dl class="notes"> |
| <dt>Type Parameters:</dt> |
| <dd><code>VR</code> - the value type of the result stream</dd> |
| <dt>Parameters:</dt> |
| <dd><code>valueTransformerSupplier</code> - an instance of <a href="ValueTransformerWithKeySupplier.html" title="interface in org.apache.kafka.streams.kstream"><code>ValueTransformerWithKeySupplier</code></a> that generates a newly constructed <a href="ValueTransformerWithKey.html" title="interface in org.apache.kafka.streams.kstream"><code>ValueTransformerWithKey</code></a> |
| The supplier should always generate a new instance. Creating a single <a href="ValueTransformerWithKey.html" title="interface in org.apache.kafka.streams.kstream"><code>ValueTransformerWithKey</code></a> object |
| and returning the same object reference in <a href="ValueTransformerWithKey.html" title="interface in org.apache.kafka.streams.kstream"><code>ValueTransformerWithKey</code></a> is a |
| violation of the supplier pattern and leads to runtime exceptions.</dd> |
| <dd><code>stateStoreNames</code> - the names of the state stores used by the processor; not required if the supplier |
| implements <a href="../processor/ConnectedStoreProvider.html#stores()"><code>ConnectedStoreProvider.stores()</code></a></dd> |
| <dt>Returns:</dt> |
| <dd>a <code>KStream</code> that contains records with unmodified key and new values (possibly of different type)</dd> |
| <dt>See Also:</dt> |
| <dd> |
| <ul class="see-list-long"> |
| <li><a href="#mapValues(org.apache.kafka.streams.kstream.ValueMapper)"><code>mapValues(ValueMapper)</code></a></li> |
| <li><a href="#mapValues(org.apache.kafka.streams.kstream.ValueMapperWithKey)"><code>mapValues(ValueMapperWithKey)</code></a></li> |
| <li><a href="#transform(org.apache.kafka.streams.kstream.TransformerSupplier,java.lang.String...)"><code>transform(TransformerSupplier, String...)</code></a></li> |
| </ul> |
| </dd> |
| </dl> |
| </section> |
| </li> |
| <li> |
| <section class="detail" id="transformValues(org.apache.kafka.streams.kstream.ValueTransformerWithKeySupplier,org.apache.kafka.streams.kstream.Named,java.lang.String...)"> |
| <h3>transformValues</h3> |
| <div class="member-signature"><span class="type-parameters"><VR></span> <span class="return-type"><a href="KStream.html" title="interface in org.apache.kafka.streams.kstream">KStream</a><<a href="KStream.html" title="type parameter in KStream">K</a>,<wbr>VR></span> <span class="element-name">transformValues</span><wbr><span class="parameters">(<a href="ValueTransformerWithKeySupplier.html" title="interface in org.apache.kafka.streams.kstream">ValueTransformerWithKeySupplier</a><? super <a href="KStream.html" title="type parameter in KStream">K</a>,<wbr>? super <a href="KStream.html" title="type parameter in KStream">V</a>,<wbr>? extends VR> valueTransformerSupplier, |
| <a href="Named.html" title="class in org.apache.kafka.streams.kstream">Named</a> named, |
| <a href="https://docs.oracle.com/en/java/javase/17/docs/api/java.base/java/lang/String.html" title="class or interface in java.lang" class="external-link">String</a>... stateStoreNames)</span></div> |
| <div class="block">Transform the value of each input record into a new value (with possibly a new type) of the output record. |
| A <a href="ValueTransformerWithKey.html" title="interface in org.apache.kafka.streams.kstream"><code>ValueTransformerWithKey</code></a> (provided by the given <a href="ValueTransformerWithKeySupplier.html" title="interface in org.apache.kafka.streams.kstream"><code>ValueTransformerWithKeySupplier</code></a>) is applied to |
| each input record value and computes a new value for it. |
| Thus, an input record <code><K,V></code> can be transformed into an output record <code><K:V'></code>. |
| Attaching a state store makes this a stateful record-by-record operation (cf. <a href="#mapValues(org.apache.kafka.streams.kstream.ValueMapperWithKey)"><code>mapValues()</code></a>). |
| If you choose not to attach one, this operation is similar to the stateless <a href="#mapValues(org.apache.kafka.streams.kstream.ValueMapperWithKey)"><code>mapValues()</code></a> |
| but allows access to the <code>ProcessorContext</code> and record metadata. |
| This is essentially mixing the Processor API into the DSL, and provides all the functionality of the PAPI. |
| Furthermore, via <a href="../processor/Punctuator.html#punctuate(long)"><code>Punctuator.punctuate(long)</code></a> the processing progress |
| can be observed and additional periodic actions can be performed. |
| <p> |
| In order for the transformer to use state stores, the stores must be added to the topology and connected to the |
| transformer using at least one of two strategies (though it's not required to connect global state stores; read-only |
| access to global state stores is available by default). |
| <p> |
| The first strategy is to manually add the <a href="../state/StoreBuilder.html" title="interface in org.apache.kafka.streams.state"><code>StoreBuilder</code></a>s via <a href="../Topology.html#addStateStore(org.apache.kafka.streams.state.StoreBuilder,java.lang.String...)"><code>Topology.addStateStore(StoreBuilder, String...)</code></a>, |
| and specify the store names via <code>stateStoreNames</code> so they will be connected to the transformer. |
| <pre><code> |
| // create store |
| StoreBuilder<KeyValueStore<String,String>> keyValueStoreBuilder = |
| Stores.keyValueStoreBuilder(Stores.persistentKeyValueStore("myValueTransformState"), |
| Serdes.String(), |
| Serdes.String()); |
| // add store |
| builder.addStateStore(keyValueStoreBuilder); |
| |
| KStream outputStream = inputStream.transformValues(new ValueTransformerWithKeySupplier() { |
| public ValueTransformerWithKey get() { |
| return new MyValueTransformerWithKey(); |
| } |
| }, "myValueTransformState"); |
| </code></pre> |
| The second strategy is for the given <a href="ValueTransformerWithKeySupplier.html" title="interface in org.apache.kafka.streams.kstream"><code>ValueTransformerWithKeySupplier</code></a> to implement <a href="../processor/ConnectedStoreProvider.html#stores()"><code>ConnectedStoreProvider.stores()</code></a>, |
| which provides the <a href="../state/StoreBuilder.html" title="interface in org.apache.kafka.streams.state"><code>StoreBuilder</code></a>s to be automatically added to the topology and connected to the transformer. |
| <pre><code> |
| class MyValueTransformerWithKeySupplier implements ValueTransformerWithKeySupplier { |
| // supply transformer |
| ValueTransformerWithKey get() { |
| return new MyValueTransformerWithKey(); |
| } |
| |
| // provide store(s) that will be added and connected to the associated transformer |
| // the store name from the builder ("myValueTransformState") is used to access the store later via the ProcessorContext |
| Set<StoreBuilder> stores() { |
| StoreBuilder<KeyValueStore<String, String>> keyValueStoreBuilder = |
| Stores.keyValueStoreBuilder(Stores.persistentKeyValueStore("myValueTransformState"), |
| Serdes.String(), |
| Serdes.String()); |
| return Collections.singleton(keyValueStoreBuilder); |
| } |
| } |
| |
| ... |
| |
| KStream outputStream = inputStream.transformValues(new MyValueTransformerWithKeySupplier()); |
| </code></pre> |
| <p> |
| With either strategy, within the <a href="ValueTransformerWithKey.html" title="interface in org.apache.kafka.streams.kstream"><code>ValueTransformerWithKey</code></a>, the state is obtained via the <a href="../processor/api/ProcessorContext.html" title="interface in org.apache.kafka.streams.processor.api"><code>ProcessorContext</code></a>. |
| To trigger periodic actions via <a href="../processor/Punctuator.html#punctuate(long)"><code>punctuate()</code></a>, |
| a schedule must be registered. |
| The <a href="ValueTransformerWithKey.html" title="interface in org.apache.kafka.streams.kstream"><code>ValueTransformerWithKey</code></a> must return the new value in |
| <a href="ValueTransformerWithKey.html#transform(K,V)"><code>transform()</code></a>. |
| In contrast to <a href="#transform(org.apache.kafka.streams.kstream.TransformerSupplier,java.lang.String...)"><code>transform()</code></a> and |
| <a href="#flatTransform(org.apache.kafka.streams.kstream.TransformerSupplier,java.lang.String...)"><code>flatTransform()</code></a>, no additional <a href="../KeyValue.html" title="class in org.apache.kafka.streams"><code>KeyValue</code></a> pairs |
| can be emitted via |
| <a href="../processor/ProcessorContext.html#forward(K,V)"><code>ProcessorContext.forward()</code></a>. |
| A <a href="../errors/StreamsException.html" title="class in org.apache.kafka.streams.errors"><code>StreamsException</code></a> is thrown if the <a href="ValueTransformerWithKey.html" title="interface in org.apache.kafka.streams.kstream"><code>ValueTransformerWithKey</code></a> tries |
| to emit a <a href="../KeyValue.html" title="class in org.apache.kafka.streams"><code>KeyValue</code></a> pair. |
| <pre><code> |
| class MyValueTransformerWithKey implements ValueTransformerWithKey { |
| private StateStore state; |
| |
| void init(ProcessorContext context) { |
| this.state = context.getStateStore("myValueTransformState"); |
| // punctuate each second, can access this.state |
| context.schedule(Duration.ofSeconds(1), PunctuationType.WALL_CLOCK_TIME, new Punctuator(..)); |
| } |
| |
| NewValueType transform(K readOnlyKey, V value) { |
| // can access this.state and use read-only key |
| return new NewValueType(readOnlyKey); // or null |
| } |
| |
| void close() { |
| // can access this.state |
| } |
| } |
| </code></pre> |
| Even if any upstream operation was key-changing, no auto-repartition is triggered. |
| If repartitioning is required, a call to <a href="#repartition()"><code>repartition()</code></a> should be performed before |
| <code>transformValues()</code>. |
| <p> |
| Note that the key is read-only and should not be modified, as this can lead to corrupt partitioning. |
| So, setting a new value preserves data co-location with respect to the key. |
| Thus, <em>no</em> internal data redistribution is required if a key based operator (like an aggregation or join) |
| is applied to the result <code>KStream</code>. (cf. <a href="#transform(org.apache.kafka.streams.kstream.TransformerSupplier,java.lang.String...)"><code>transform(TransformerSupplier, String...)</code></a>)</div> |
| <dl class="notes"> |
| <dt>Type Parameters:</dt> |
| <dd><code>VR</code> - the value type of the result stream</dd> |
| <dt>Parameters:</dt> |
| <dd><code>valueTransformerSupplier</code> - an instance of <a href="ValueTransformerWithKeySupplier.html" title="interface in org.apache.kafka.streams.kstream"><code>ValueTransformerWithKeySupplier</code></a> that generates a newly constructed <a href="ValueTransformerWithKey.html" title="interface in org.apache.kafka.streams.kstream"><code>ValueTransformerWithKey</code></a> |
| The supplier should always generate a new instance. Creating a single <a href="ValueTransformerWithKey.html" title="interface in org.apache.kafka.streams.kstream"><code>ValueTransformerWithKey</code></a> object |
| and returning the same object reference in <a href="ValueTransformerWithKey.html" title="interface in org.apache.kafka.streams.kstream"><code>ValueTransformerWithKey</code></a> is a |
| violation of the supplier pattern and leads to runtime exceptions.</dd> |
| <dd><code>named</code> - a <a href="Named.html" title="class in org.apache.kafka.streams.kstream"><code>Named</code></a> config used to name the processor in the topology</dd> |
| <dd><code>stateStoreNames</code> - the names of the state stores used by the processor; not required if the supplier |
| implements <a href="../processor/ConnectedStoreProvider.html#stores()"><code>ConnectedStoreProvider.stores()</code></a></dd> |
| <dt>Returns:</dt> |
| <dd>a <code>KStream</code> that contains records with unmodified key and new values (possibly of different type)</dd> |
| <dt>See Also:</dt> |
| <dd> |
| <ul class="see-list-long"> |
| <li><a href="#mapValues(org.apache.kafka.streams.kstream.ValueMapper)"><code>mapValues(ValueMapper)</code></a></li> |
| <li><a href="#mapValues(org.apache.kafka.streams.kstream.ValueMapperWithKey)"><code>mapValues(ValueMapperWithKey)</code></a></li> |
| <li><a href="#transform(org.apache.kafka.streams.kstream.TransformerSupplier,java.lang.String...)"><code>transform(TransformerSupplier, String...)</code></a></li> |
| </ul> |
| </dd> |
| </dl> |
| </section> |
| </li> |
| <li> |
| <section class="detail" id="flatTransformValues(org.apache.kafka.streams.kstream.ValueTransformerSupplier,java.lang.String...)"> |
| <h3>flatTransformValues</h3> |
| <div class="member-signature"><span class="type-parameters"><VR></span> <span class="return-type"><a href="KStream.html" title="interface in org.apache.kafka.streams.kstream">KStream</a><<a href="KStream.html" title="type parameter in KStream">K</a>,<wbr>VR></span> <span class="element-name">flatTransformValues</span><wbr><span class="parameters">(<a href="ValueTransformerSupplier.html" title="interface in org.apache.kafka.streams.kstream">ValueTransformerSupplier</a><? super <a href="KStream.html" title="type parameter in KStream">V</a>,<wbr><a href="https://docs.oracle.com/en/java/javase/17/docs/api/java.base/java/lang/Iterable.html" title="class or interface in java.lang" class="external-link">Iterable</a><VR>> valueTransformerSupplier, |
| <a href="https://docs.oracle.com/en/java/javase/17/docs/api/java.base/java/lang/String.html" title="class or interface in java.lang" class="external-link">String</a>... stateStoreNames)</span></div> |
| <div class="block">Transform the value of each input record into zero or more new values (with possibly a new |
| type) and emit for each new value a record with the same key of the input record and the value. |
| A <a href="ValueTransformer.html" title="interface in org.apache.kafka.streams.kstream"><code>ValueTransformer</code></a> (provided by the given <a href="ValueTransformerSupplier.html" title="interface in org.apache.kafka.streams.kstream"><code>ValueTransformerSupplier</code></a>) is applied to each input |
| record value and computes zero or more new values. |
| Thus, an input record <code><K,V></code> can be transformed into output records <code><K:V'>, <K:V''>, ...</code>. |
| Attaching a state store makes this a stateful record-by-record operation (cf. <a href="#mapValues(org.apache.kafka.streams.kstream.ValueMapper)"><code>mapValues()</code></a>). |
| If you choose not to attach one, this operation is similar to the stateless <a href="#mapValues(org.apache.kafka.streams.kstream.ValueMapper)"><code>mapValues()</code></a> |
| but allows access to the <code>ProcessorContext</code> and record metadata. |
| This is essentially mixing the Processor API into the DSL, and provides all the functionality of the PAPI. |
| Furthermore, via <a href="../processor/Punctuator.html#punctuate(long)"><code>Punctuator#punctuate()</code></a> |
| the processing progress can be observed and additional periodic actions can be performed. |
| <p> |
| In order for the transformer to use state stores, the stores must be added to the topology and connected to the |
| transformer using at least one of two strategies (though it's not required to connect global state stores; read-only |
| access to global state stores is available by default). |
| <p> |
| The first strategy is to manually add the <a href="../state/StoreBuilder.html" title="interface in org.apache.kafka.streams.state"><code>StoreBuilder</code></a>s via <a href="../Topology.html#addStateStore(org.apache.kafka.streams.state.StoreBuilder,java.lang.String...)"><code>Topology.addStateStore(StoreBuilder, String...)</code></a>, |
| and specify the store names via <code>stateStoreNames</code> so they will be connected to the transformer. |
| <pre><code> |
| // create store |
| StoreBuilder<KeyValueStore<String,String>> keyValueStoreBuilder = |
| Stores.keyValueStoreBuilder(Stores.persistentKeyValueStore("myValueTransformState"), |
| Serdes.String(), |
| Serdes.String()); |
| // add store |
| builder.addStateStore(keyValueStoreBuilder); |
| |
| KStream outputStream = inputStream.flatTransformValues(new ValueTransformerSupplier() { |
| public ValueTransformer get() { |
| return new MyValueTransformer(); |
| } |
| }, "myValueTransformState"); |
| </code></pre> |
| The second strategy is for the given <a href="ValueTransformerSupplier.html" title="interface in org.apache.kafka.streams.kstream"><code>ValueTransformerSupplier</code></a> to implement <a href="../processor/ConnectedStoreProvider.html#stores()"><code>ConnectedStoreProvider.stores()</code></a>, |
| which provides the <a href="../state/StoreBuilder.html" title="interface in org.apache.kafka.streams.state"><code>StoreBuilder</code></a>s to be automatically added to the topology and connected to the transformer. |
| <pre><code> |
| class MyValueTransformerSupplier implements ValueTransformerSupplier { |
| // supply transformer |
| ValueTransformerWithKey get() { |
| return new MyValueTransformerWithKey(); |
| } |
| |
| // provide store(s) that will be added and connected to the associated transformer |
| // the store name from the builder ("myValueTransformState") is used to access the store later via the ProcessorContext |
| Set<StoreBuilder> stores() { |
| StoreBuilder<KeyValueStore<String, String>> keyValueStoreBuilder = |
| Stores.keyValueStoreBuilder(Stores.persistentKeyValueStore("myValueTransformState"), |
| Serdes.String(), |
| Serdes.String()); |
| return Collections.singleton(keyValueStoreBuilder); |
| } |
| } |
| |
| ... |
| |
| KStream outputStream = inputStream.flatTransformValues(new MyValueTransformer()); |
| </code></pre> |
| <p> |
| With either strategy, within the <a href="ValueTransformer.html" title="interface in org.apache.kafka.streams.kstream"><code>ValueTransformer</code></a>, the state is obtained via the <a href="../processor/api/ProcessorContext.html" title="interface in org.apache.kafka.streams.processor.api"><code>ProcessorContext</code></a>. |
| To trigger periodic actions via <a href="../processor/Punctuator.html#punctuate(long)"><code>punctuate()</code></a>, |
| a schedule must be registered. |
| The <a href="ValueTransformer.html" title="interface in org.apache.kafka.streams.kstream"><code>ValueTransformer</code></a> must return an <a href="https://docs.oracle.com/en/java/javase/17/docs/api/java.base/java/lang/Iterable.html" title="class or interface in java.lang" class="external-link"><code>Iterable</code></a> type (e.g., any |
| <a href="https://docs.oracle.com/en/java/javase/17/docs/api/java.base/java/util/Collection.html" title="class or interface in java.util" class="external-link"><code>Collection</code></a> type) in <a href="ValueTransformer.html#transform(V)"><code>transform()</code></a>. |
| If the return value of <a href="ValueTransformer.html#transform(V)"><code>ValueTransformer#transform()</code></a> is an empty |
| <a href="https://docs.oracle.com/en/java/javase/17/docs/api/java.base/java/lang/Iterable.html" title="class or interface in java.lang" class="external-link"><code>Iterable</code></a> or <code>null</code>, no records are emitted. |
| In contrast to <a href="#transform(org.apache.kafka.streams.kstream.TransformerSupplier,java.lang.String...)"><code>transform()</code></a> and |
| <a href="#flatTransform(org.apache.kafka.streams.kstream.TransformerSupplier,java.lang.String...)"><code>flatTransform()</code></a>, no additional <a href="../KeyValue.html" title="class in org.apache.kafka.streams"><code>KeyValue</code></a> pairs |
| can be emitted via |
| <a href="../processor/ProcessorContext.html#forward(K,V)"><code>ProcessorContext.forward()</code></a>. |
| A <a href="../errors/StreamsException.html" title="class in org.apache.kafka.streams.errors"><code>StreamsException</code></a> is thrown if the <a href="ValueTransformer.html" title="interface in org.apache.kafka.streams.kstream"><code>ValueTransformer</code></a> tries to |
| emit a <a href="../KeyValue.html" title="class in org.apache.kafka.streams"><code>KeyValue</code></a> pair. |
| <pre><code> |
| class MyValueTransformer implements ValueTransformer { |
| private StateStore state; |
| |
| void init(ProcessorContext context) { |
| this.state = context.getStateStore("myValueTransformState"); |
| // punctuate each second, can access this.state |
| context.schedule(Duration.ofSeconds(1), PunctuationType.WALL_CLOCK_TIME, new Punctuator(..)); |
| } |
| |
| Iterable<NewValueType> transform(V value) { |
| // can access this.state |
| List<NewValueType> result = new ArrayList<>(); |
| for (int i = 0; i < 3; i++) { |
| result.add(new NewValueType(value)); |
| } |
| return result; // values |
| } |
| |
| void close() { |
| // can access this.state |
| } |
| } |
| </code></pre> |
| Even if any upstream operation was key-changing, no auto-repartition is triggered. |
| If repartitioning is required, a call to <a href="#repartition()"><code>repartition()</code></a> should be performed before |
| <code>flatTransformValues()</code>. |
| <p> |
| Setting a new value preserves data co-location with respect to the key. |
| Thus, <em>no</em> internal data redistribution is required if a key based operator (like an aggregation or join) |
| is applied to the result <code>KStream</code>. (cf. <a href="#flatTransform(org.apache.kafka.streams.kstream.TransformerSupplier,java.lang.String...)"><code>flatTransform()</code></a>)</div> |
| <dl class="notes"> |
| <dt>Type Parameters:</dt> |
| <dd><code>VR</code> - the value type of the result stream</dd> |
| <dt>Parameters:</dt> |
| <dd><code>valueTransformerSupplier</code> - an instance of <a href="ValueTransformerSupplier.html" title="interface in org.apache.kafka.streams.kstream"><code>ValueTransformerSupplier</code></a> that generates a newly constructed <a href="ValueTransformer.html" title="interface in org.apache.kafka.streams.kstream"><code>ValueTransformer</code></a> |
| The supplier should always generate a new instance. Creating a single <a href="ValueTransformer.html" title="interface in org.apache.kafka.streams.kstream"><code>ValueTransformer</code></a> object |
| and returning the same object reference in <a href="ValueTransformer.html" title="interface in org.apache.kafka.streams.kstream"><code>ValueTransformer</code></a> is a |
| violation of the supplier pattern and leads to runtime exceptions.</dd> |
| <dd><code>stateStoreNames</code> - the names of the state stores used by the processor; not required if the supplier |
| implements <a href="../processor/ConnectedStoreProvider.html#stores()"><code>ConnectedStoreProvider.stores()</code></a></dd> |
| <dt>Returns:</dt> |
| <dd>a <code>KStream</code> that contains more or less records with unmodified key and new values (possibly of |
| different type)</dd> |
| <dt>See Also:</dt> |
| <dd> |
| <ul class="see-list-long"> |
| <li><a href="#mapValues(org.apache.kafka.streams.kstream.ValueMapper)"><code>mapValues(ValueMapper)</code></a></li> |
| <li><a href="#mapValues(org.apache.kafka.streams.kstream.ValueMapperWithKey)"><code>mapValues(ValueMapperWithKey)</code></a></li> |
| <li><a href="#transform(org.apache.kafka.streams.kstream.TransformerSupplier,java.lang.String...)"><code>transform(TransformerSupplier, String...)</code></a></li> |
| <li><a href="#flatTransform(org.apache.kafka.streams.kstream.TransformerSupplier,java.lang.String...)"><code>flatTransform(TransformerSupplier, String...)</code></a></li> |
| </ul> |
| </dd> |
| </dl> |
| </section> |
| </li> |
| <li> |
| <section class="detail" id="flatTransformValues(org.apache.kafka.streams.kstream.ValueTransformerSupplier,org.apache.kafka.streams.kstream.Named,java.lang.String...)"> |
| <h3>flatTransformValues</h3> |
| <div class="member-signature"><span class="type-parameters"><VR></span> <span class="return-type"><a href="KStream.html" title="interface in org.apache.kafka.streams.kstream">KStream</a><<a href="KStream.html" title="type parameter in KStream">K</a>,<wbr>VR></span> <span class="element-name">flatTransformValues</span><wbr><span class="parameters">(<a href="ValueTransformerSupplier.html" title="interface in org.apache.kafka.streams.kstream">ValueTransformerSupplier</a><? super <a href="KStream.html" title="type parameter in KStream">V</a>,<wbr><a href="https://docs.oracle.com/en/java/javase/17/docs/api/java.base/java/lang/Iterable.html" title="class or interface in java.lang" class="external-link">Iterable</a><VR>> valueTransformerSupplier, |
| <a href="Named.html" title="class in org.apache.kafka.streams.kstream">Named</a> named, |
| <a href="https://docs.oracle.com/en/java/javase/17/docs/api/java.base/java/lang/String.html" title="class or interface in java.lang" class="external-link">String</a>... stateStoreNames)</span></div> |
| <div class="block">Transform the value of each input record into zero or more new values (with possibly a new |
| type) and emit for each new value a record with the same key of the input record and the value. |
| A <a href="ValueTransformer.html" title="interface in org.apache.kafka.streams.kstream"><code>ValueTransformer</code></a> (provided by the given <a href="ValueTransformerSupplier.html" title="interface in org.apache.kafka.streams.kstream"><code>ValueTransformerSupplier</code></a>) is applied to each input |
| record value and computes zero or more new values. |
| Thus, an input record <code><K,V></code> can be transformed into output records <code><K:V'>, <K:V''>, ...</code>. |
| Attaching a state store makes this a stateful record-by-record operation (cf. <a href="#mapValues(org.apache.kafka.streams.kstream.ValueMapper)"><code>mapValues()</code></a>). |
| If you choose not to attach one, this operation is similar to the stateless <a href="#mapValues(org.apache.kafka.streams.kstream.ValueMapper)"><code>mapValues()</code></a> |
| but allows access to the <code>ProcessorContext</code> and record metadata. |
| This is essentially mixing the Processor API into the DSL, and provides all the functionality of the PAPI. |
| Furthermore, via <a href="../processor/Punctuator.html#punctuate(long)"><code>Punctuator#punctuate()</code></a> |
| the processing progress can be observed and additional periodic actions can be performed. |
| <p> |
| In order for the transformer to use state stores, the stores must be added to the topology and connected to the |
| transformer using at least one of two strategies (though it's not required to connect global state stores; read-only |
| access to global state stores is available by default). |
| <p> |
| The first strategy is to manually add the <a href="../state/StoreBuilder.html" title="interface in org.apache.kafka.streams.state"><code>StoreBuilder</code></a>s via <a href="../Topology.html#addStateStore(org.apache.kafka.streams.state.StoreBuilder,java.lang.String...)"><code>Topology.addStateStore(StoreBuilder, String...)</code></a>, |
| and specify the store names via <code>stateStoreNames</code> so they will be connected to the transformer. |
| <pre><code> |
| // create store |
| StoreBuilder<KeyValueStore<String,String>> keyValueStoreBuilder = |
| Stores.keyValueStoreBuilder(Stores.persistentKeyValueStore("myValueTransformState"), |
| Serdes.String(), |
| Serdes.String()); |
| // add store |
| builder.addStateStore(keyValueStoreBuilder); |
| |
| KStream outputStream = inputStream.flatTransformValues(new ValueTransformerSupplier() { |
| public ValueTransformer get() { |
| return new MyValueTransformer(); |
| } |
| }, "myValueTransformState"); |
| </code></pre> |
| The second strategy is for the given <a href="ValueTransformerSupplier.html" title="interface in org.apache.kafka.streams.kstream"><code>ValueTransformerSupplier</code></a> to implement <a href="../processor/ConnectedStoreProvider.html#stores()"><code>ConnectedStoreProvider.stores()</code></a>, |
| which provides the <a href="../state/StoreBuilder.html" title="interface in org.apache.kafka.streams.state"><code>StoreBuilder</code></a>s to be automatically added to the topology and connected to the transformer. |
| <pre><code> |
| class MyValueTransformerSupplier implements ValueTransformerSupplier { |
| // supply transformer |
| ValueTransformerWithKey get() { |
| return new MyValueTransformerWithKey(); |
| } |
| |
| // provide store(s) that will be added and connected to the associated transformer |
| // the store name from the builder ("myValueTransformState") is used to access the store later via the ProcessorContext |
| Set<StoreBuilder> stores() { |
| StoreBuilder<KeyValueStore<String, String>> keyValueStoreBuilder = |
| Stores.keyValueStoreBuilder(Stores.persistentKeyValueStore("myValueTransformState"), |
| Serdes.String(), |
| Serdes.String()); |
| return Collections.singleton(keyValueStoreBuilder); |
| } |
| } |
| |
| ... |
| |
| KStream outputStream = inputStream.flatTransformValues(new MyValueTransformer()); |
| </code></pre> |
| <p> |
| With either strategy, within the <a href="ValueTransformer.html" title="interface in org.apache.kafka.streams.kstream"><code>ValueTransformer</code></a>, the state is obtained via the <a href="../processor/api/ProcessorContext.html" title="interface in org.apache.kafka.streams.processor.api"><code>ProcessorContext</code></a>. |
| To trigger periodic actions via <a href="../processor/Punctuator.html#punctuate(long)"><code>punctuate()</code></a>, |
| a schedule must be registered. |
| The <a href="ValueTransformer.html" title="interface in org.apache.kafka.streams.kstream"><code>ValueTransformer</code></a> must return an <a href="https://docs.oracle.com/en/java/javase/17/docs/api/java.base/java/lang/Iterable.html" title="class or interface in java.lang" class="external-link"><code>Iterable</code></a> type (e.g., any |
| <a href="https://docs.oracle.com/en/java/javase/17/docs/api/java.base/java/util/Collection.html" title="class or interface in java.util" class="external-link"><code>Collection</code></a> type) in <a href="ValueTransformer.html#transform(V)"><code>transform()</code></a>. |
| If the return value of <a href="ValueTransformer.html#transform(V)"><code>ValueTransformer#transform()</code></a> is an empty |
| <a href="https://docs.oracle.com/en/java/javase/17/docs/api/java.base/java/lang/Iterable.html" title="class or interface in java.lang" class="external-link"><code>Iterable</code></a> or <code>null</code>, no records are emitted. |
| In contrast to <a href="#transform(org.apache.kafka.streams.kstream.TransformerSupplier,java.lang.String...)"><code>transform()</code></a> and |
| <a href="#flatTransform(org.apache.kafka.streams.kstream.TransformerSupplier,java.lang.String...)"><code>flatTransform()</code></a>, no additional <a href="../KeyValue.html" title="class in org.apache.kafka.streams"><code>KeyValue</code></a> pairs |
| can be emitted via |
| <a href="../processor/ProcessorContext.html#forward(K,V)"><code>ProcessorContext.forward()</code></a>. |
| A <a href="../errors/StreamsException.html" title="class in org.apache.kafka.streams.errors"><code>StreamsException</code></a> is thrown if the <a href="ValueTransformer.html" title="interface in org.apache.kafka.streams.kstream"><code>ValueTransformer</code></a> tries to |
| emit a <a href="../KeyValue.html" title="class in org.apache.kafka.streams"><code>KeyValue</code></a> pair. |
| <pre><code> |
| class MyValueTransformer implements ValueTransformer { |
| private StateStore state; |
| |
| void init(ProcessorContext context) { |
| this.state = context.getStateStore("myValueTransformState"); |
| // punctuate each second, can access this.state |
| context.schedule(Duration.ofSeconds(1), PunctuationType.WALL_CLOCK_TIME, new Punctuator(..)); |
| } |
| |
| Iterable<NewValueType> transform(V value) { |
| // can access this.state |
| List<NewValueType> result = new ArrayList<>(); |
| for (int i = 0; i < 3; i++) { |
| result.add(new NewValueType(value)); |
| } |
| return result; // values |
| } |
| |
| void close() { |
| // can access this.state |
| } |
| } |
| </code></pre> |
| Even if any upstream operation was key-changing, no auto-repartition is triggered. |
| If repartitioning is required, a call to <a href="#repartition()"><code>repartition()</code></a> should be performed before |
| <code>flatTransformValues()</code>. |
| <p> |
| Setting a new value preserves data co-location with respect to the key. |
| Thus, <em>no</em> internal data redistribution is required if a key based operator (like an aggregation or join) |
| is applied to the result <code>KStream</code>. (cf. <a href="#flatTransform(org.apache.kafka.streams.kstream.TransformerSupplier,java.lang.String...)"><code>flatTransform()</code></a>)</div> |
| <dl class="notes"> |
| <dt>Type Parameters:</dt> |
| <dd><code>VR</code> - the value type of the result stream</dd> |
| <dt>Parameters:</dt> |
| <dd><code>valueTransformerSupplier</code> - an instance of <a href="ValueTransformerSupplier.html" title="interface in org.apache.kafka.streams.kstream"><code>ValueTransformerSupplier</code></a> that generates a newly constructed <a href="ValueTransformer.html" title="interface in org.apache.kafka.streams.kstream"><code>ValueTransformer</code></a> |
| The supplier should always generate a new instance. Creating a single <a href="ValueTransformer.html" title="interface in org.apache.kafka.streams.kstream"><code>ValueTransformer</code></a> object |
| and returning the same object reference in <a href="ValueTransformer.html" title="interface in org.apache.kafka.streams.kstream"><code>ValueTransformer</code></a> is a |
| violation of the supplier pattern and leads to runtime exceptions.</dd> |
| <dd><code>named</code> - a <a href="Named.html" title="class in org.apache.kafka.streams.kstream"><code>Named</code></a> config used to name the processor in the topology</dd> |
| <dd><code>stateStoreNames</code> - the names of the state stores used by the processor; not required if the supplier |
| implements <a href="../processor/ConnectedStoreProvider.html#stores()"><code>ConnectedStoreProvider.stores()</code></a></dd> |
| <dt>Returns:</dt> |
| <dd>a <code>KStream</code> that contains more or less records with unmodified key and new values (possibly of |
| different type)</dd> |
| <dt>See Also:</dt> |
| <dd> |
| <ul class="see-list-long"> |
| <li><a href="#mapValues(org.apache.kafka.streams.kstream.ValueMapper)"><code>mapValues(ValueMapper)</code></a></li> |
| <li><a href="#mapValues(org.apache.kafka.streams.kstream.ValueMapperWithKey)"><code>mapValues(ValueMapperWithKey)</code></a></li> |
| <li><a href="#transform(org.apache.kafka.streams.kstream.TransformerSupplier,java.lang.String...)"><code>transform(TransformerSupplier, String...)</code></a></li> |
| <li><a href="#flatTransform(org.apache.kafka.streams.kstream.TransformerSupplier,java.lang.String...)"><code>flatTransform(TransformerSupplier, String...)</code></a></li> |
| </ul> |
| </dd> |
| </dl> |
| </section> |
| </li> |
| <li> |
| <section class="detail" id="flatTransformValues(org.apache.kafka.streams.kstream.ValueTransformerWithKeySupplier,java.lang.String...)"> |
| <h3>flatTransformValues</h3> |
| <div class="member-signature"><span class="type-parameters"><VR></span> <span class="return-type"><a href="KStream.html" title="interface in org.apache.kafka.streams.kstream">KStream</a><<a href="KStream.html" title="type parameter in KStream">K</a>,<wbr>VR></span> <span class="element-name">flatTransformValues</span><wbr><span class="parameters">(<a href="ValueTransformerWithKeySupplier.html" title="interface in org.apache.kafka.streams.kstream">ValueTransformerWithKeySupplier</a><? super <a href="KStream.html" title="type parameter in KStream">K</a>,<wbr>? super <a href="KStream.html" title="type parameter in KStream">V</a>,<wbr><a href="https://docs.oracle.com/en/java/javase/17/docs/api/java.base/java/lang/Iterable.html" title="class or interface in java.lang" class="external-link">Iterable</a><VR>> valueTransformerSupplier, |
| <a href="https://docs.oracle.com/en/java/javase/17/docs/api/java.base/java/lang/String.html" title="class or interface in java.lang" class="external-link">String</a>... stateStoreNames)</span></div> |
| <div class="block">Transform the value of each input record into zero or more new values (with possibly a new |
| type) and emit for each new value a record with the same key of the input record and the value. |
| A <a href="ValueTransformerWithKey.html" title="interface in org.apache.kafka.streams.kstream"><code>ValueTransformerWithKey</code></a> (provided by the given <a href="ValueTransformerWithKeySupplier.html" title="interface in org.apache.kafka.streams.kstream"><code>ValueTransformerWithKeySupplier</code></a>) is applied to |
| each input record value and computes zero or more new values. |
| Thus, an input record <code><K,V></code> can be transformed into output records <code><K:V'>, <K:V''>, ...</code>. |
| Attaching a state store makes this a stateful record-by-record operation (cf. <a href="#flatMapValues(org.apache.kafka.streams.kstream.ValueMapperWithKey)"><code>flatMapValues()</code></a>). |
| If you choose not to attach one, this operation is similar to the stateless <a href="#flatMapValues(org.apache.kafka.streams.kstream.ValueMapperWithKey)"><code>flatMapValues()</code></a> |
| but allows access to the <code>ProcessorContext</code> and record metadata. |
| This is essentially mixing the Processor API into the DSL, and provides all the functionality of the PAPI. |
| Furthermore, via <a href="../processor/Punctuator.html#punctuate(long)"><code>Punctuator.punctuate(long)</code></a> the processing progress can |
| be observed and additional periodic actions can be performed. |
| <p> |
| In order for the transformer to use state stores, the stores must be added to the topology and connected to the |
| transformer using at least one of two strategies (though it's not required to connect global state stores; read-only |
| access to global state stores is available by default). |
| <p> |
| The first strategy is to manually add the <a href="../state/StoreBuilder.html" title="interface in org.apache.kafka.streams.state"><code>StoreBuilder</code></a>s via <a href="../Topology.html#addStateStore(org.apache.kafka.streams.state.StoreBuilder,java.lang.String...)"><code>Topology.addStateStore(StoreBuilder, String...)</code></a>, |
| and specify the store names via <code>stateStoreNames</code> so they will be connected to the transformer. |
| <pre><code> |
| // create store |
| StoreBuilder<KeyValueStore<String,String>> keyValueStoreBuilder = |
| Stores.keyValueStoreBuilder(Stores.persistentKeyValueStore("myValueTransformState"), |
| Serdes.String(), |
| Serdes.String()); |
| // add store |
| builder.addStateStore(keyValueStoreBuilder); |
| |
| KStream outputStream = inputStream.flatTransformValues(new ValueTransformerWithKeySupplier() { |
| public ValueTransformerWithKey get() { |
| return new MyValueTransformerWithKey(); |
| } |
| }, "myValueTransformState"); |
| </code></pre> |
| The second strategy is for the given <a href="ValueTransformerSupplier.html" title="interface in org.apache.kafka.streams.kstream"><code>ValueTransformerSupplier</code></a> to implement <a href="../processor/ConnectedStoreProvider.html#stores()"><code>ConnectedStoreProvider.stores()</code></a>, |
| which provides the <a href="../state/StoreBuilder.html" title="interface in org.apache.kafka.streams.state"><code>StoreBuilder</code></a>s to be automatically added to the topology and connected to the transformer. |
| <pre><code> |
| class MyValueTransformerWithKeySupplier implements ValueTransformerWithKeySupplier { |
| // supply transformer |
| ValueTransformerWithKey get() { |
| return new MyValueTransformerWithKey(); |
| } |
| |
| // provide store(s) that will be added and connected to the associated transformer |
| // the store name from the builder ("myValueTransformState") is used to access the store later via the ProcessorContext |
| Set<StoreBuilder> stores() { |
| StoreBuilder<KeyValueStore<String, String>> keyValueStoreBuilder = |
| Stores.keyValueStoreBuilder(Stores.persistentKeyValueStore("myValueTransformState"), |
| Serdes.String(), |
| Serdes.String()); |
| return Collections.singleton(keyValueStoreBuilder); |
| } |
| } |
| |
| ... |
| |
| KStream outputStream = inputStream.flatTransformValues(new MyValueTransformerWithKey()); |
| </code></pre> |
| <p> |
| With either strategy, within the <a href="ValueTransformerWithKey.html" title="interface in org.apache.kafka.streams.kstream"><code>ValueTransformerWithKey</code></a>, the state is obtained via the <a href="../processor/api/ProcessorContext.html" title="interface in org.apache.kafka.streams.processor.api"><code>ProcessorContext</code></a>. |
| To trigger periodic actions via <a href="../processor/Punctuator.html#punctuate(long)"><code>punctuate()</code></a>, |
| a schedule must be registered. |
| The <a href="ValueTransformerWithKey.html" title="interface in org.apache.kafka.streams.kstream"><code>ValueTransformerWithKey</code></a> must return an <a href="https://docs.oracle.com/en/java/javase/17/docs/api/java.base/java/lang/Iterable.html" title="class or interface in java.lang" class="external-link"><code>Iterable</code></a> type (e.g., any |
| <a href="https://docs.oracle.com/en/java/javase/17/docs/api/java.base/java/util/Collection.html" title="class or interface in java.util" class="external-link"><code>Collection</code></a> type) in <a href="ValueTransformerWithKey.html#transform(K,V)"><code>transform()</code></a>. |
| If the return value of <a href="ValueTransformerWithKey.html#transform(K,V)"><code>ValueTransformerWithKey#transform()</code></a> |
| is an empty <a href="https://docs.oracle.com/en/java/javase/17/docs/api/java.base/java/lang/Iterable.html" title="class or interface in java.lang" class="external-link"><code>Iterable</code></a> or <code>null</code>, no records are emitted. |
| In contrast to <a href="#transform(org.apache.kafka.streams.kstream.TransformerSupplier,java.lang.String...)"><code>transform()</code></a> and |
| <a href="#flatTransform(org.apache.kafka.streams.kstream.TransformerSupplier,java.lang.String...)"><code>flatTransform()</code></a>, no additional <a href="../KeyValue.html" title="class in org.apache.kafka.streams"><code>KeyValue</code></a> pairs |
| can be emitted via |
| <a href="../processor/ProcessorContext.html#forward(K,V)"><code>ProcessorContext.forward()</code></a>. |
| A <a href="../errors/StreamsException.html" title="class in org.apache.kafka.streams.errors"><code>StreamsException</code></a> is thrown if the <a href="ValueTransformerWithKey.html" title="interface in org.apache.kafka.streams.kstream"><code>ValueTransformerWithKey</code></a> tries |
| to emit a <a href="../KeyValue.html" title="class in org.apache.kafka.streams"><code>KeyValue</code></a> pair. |
| <pre><code> |
| class MyValueTransformerWithKey implements ValueTransformerWithKey { |
| private StateStore state; |
| |
| void init(ProcessorContext context) { |
| this.state = context.getStateStore("myValueTransformState"); |
| // punctuate each second, can access this.state |
| context.schedule(Duration.ofSeconds(1), PunctuationType.WALL_CLOCK_TIME, new Punctuator(..)); |
| } |
| |
| Iterable<NewValueType> transform(K readOnlyKey, V value) { |
| // can access this.state and use read-only key |
| List<NewValueType> result = new ArrayList<>(); |
| for (int i = 0; i < 3; i++) { |
| result.add(new NewValueType(readOnlyKey)); |
| } |
| return result; // values |
| } |
| |
| void close() { |
| // can access this.state |
| } |
| } |
| </code></pre> |
| Even if any upstream operation was key-changing, no auto-repartition is triggered. |
| If repartitioning is required, a call to <a href="#repartition()"><code>repartition()</code></a> should be performed before |
| <code>flatTransformValues()</code>. |
| <p> |
| Note that the key is read-only and should not be modified, as this can lead to corrupt partitioning. |
| So, setting a new value preserves data co-location with respect to the key. |
| Thus, <em>no</em> internal data redistribution is required if a key based operator (like an aggregation or join) |
| is applied to the result <code>KStream</code>. (cf. <a href="#flatTransform(org.apache.kafka.streams.kstream.TransformerSupplier,java.lang.String...)"><code>flatTransform()</code></a>)</div> |
| <dl class="notes"> |
| <dt>Type Parameters:</dt> |
| <dd><code>VR</code> - the value type of the result stream</dd> |
| <dt>Parameters:</dt> |
| <dd><code>valueTransformerSupplier</code> - an instance of <a href="ValueTransformerWithKeySupplier.html" title="interface in org.apache.kafka.streams.kstream"><code>ValueTransformerWithKeySupplier</code></a> that generates a newly constructed <a href="ValueTransformerWithKey.html" title="interface in org.apache.kafka.streams.kstream"><code>ValueTransformerWithKey</code></a> |
| The supplier should always generate a new instance. Creating a single <a href="ValueTransformerWithKey.html" title="interface in org.apache.kafka.streams.kstream"><code>ValueTransformerWithKey</code></a> object |
| and returning the same object reference in <a href="ValueTransformerWithKey.html" title="interface in org.apache.kafka.streams.kstream"><code>ValueTransformerWithKey</code></a> is a |
| violation of the supplier pattern and leads to runtime exceptions.</dd> |
| <dd><code>stateStoreNames</code> - the names of the state stores used by the processor; not required if the supplier |
| implements <a href="../processor/ConnectedStoreProvider.html#stores()"><code>ConnectedStoreProvider.stores()</code></a></dd> |
| <dt>Returns:</dt> |
| <dd>a <code>KStream</code> that contains more or less records with unmodified key and new values (possibly of |
| different type)</dd> |
| <dt>See Also:</dt> |
| <dd> |
| <ul class="see-list-long"> |
| <li><a href="#mapValues(org.apache.kafka.streams.kstream.ValueMapper)"><code>mapValues(ValueMapper)</code></a></li> |
| <li><a href="#mapValues(org.apache.kafka.streams.kstream.ValueMapperWithKey)"><code>mapValues(ValueMapperWithKey)</code></a></li> |
| <li><a href="#transform(org.apache.kafka.streams.kstream.TransformerSupplier,java.lang.String...)"><code>transform(TransformerSupplier, String...)</code></a></li> |
| <li><a href="#flatTransform(org.apache.kafka.streams.kstream.TransformerSupplier,java.lang.String...)"><code>flatTransform(TransformerSupplier, String...)</code></a></li> |
| </ul> |
| </dd> |
| </dl> |
| </section> |
| </li> |
| <li> |
| <section class="detail" id="flatTransformValues(org.apache.kafka.streams.kstream.ValueTransformerWithKeySupplier,org.apache.kafka.streams.kstream.Named,java.lang.String...)"> |
| <h3>flatTransformValues</h3> |
| <div class="member-signature"><span class="type-parameters"><VR></span> <span class="return-type"><a href="KStream.html" title="interface in org.apache.kafka.streams.kstream">KStream</a><<a href="KStream.html" title="type parameter in KStream">K</a>,<wbr>VR></span> <span class="element-name">flatTransformValues</span><wbr><span class="parameters">(<a href="ValueTransformerWithKeySupplier.html" title="interface in org.apache.kafka.streams.kstream">ValueTransformerWithKeySupplier</a><? super <a href="KStream.html" title="type parameter in KStream">K</a>,<wbr>? super <a href="KStream.html" title="type parameter in KStream">V</a>,<wbr><a href="https://docs.oracle.com/en/java/javase/17/docs/api/java.base/java/lang/Iterable.html" title="class or interface in java.lang" class="external-link">Iterable</a><VR>> valueTransformerSupplier, |
| <a href="Named.html" title="class in org.apache.kafka.streams.kstream">Named</a> named, |
| <a href="https://docs.oracle.com/en/java/javase/17/docs/api/java.base/java/lang/String.html" title="class or interface in java.lang" class="external-link">String</a>... stateStoreNames)</span></div> |
| <div class="block">Transform the value of each input record into zero or more new values (with possibly a new |
| type) and emit for each new value a record with the same key of the input record and the value. |
| A <a href="ValueTransformerWithKey.html" title="interface in org.apache.kafka.streams.kstream"><code>ValueTransformerWithKey</code></a> (provided by the given <a href="ValueTransformerWithKeySupplier.html" title="interface in org.apache.kafka.streams.kstream"><code>ValueTransformerWithKeySupplier</code></a>) is applied to |
| each input record value and computes zero or more new values. |
| Thus, an input record <code><K,V></code> can be transformed into output records <code><K:V'>, <K:V''>, ...</code>. |
| Attaching a state store makes this a stateful record-by-record operation (cf. <a href="#flatMapValues(org.apache.kafka.streams.kstream.ValueMapperWithKey)"><code>flatMapValues()</code></a>). |
| If you choose not to attach one, this operation is similar to the stateless <a href="#flatMapValues(org.apache.kafka.streams.kstream.ValueMapperWithKey)"><code>flatMapValues()</code></a> |
| but allows access to the <code>ProcessorContext</code> and record metadata. |
| This is essentially mixing the Processor API into the DSL, and provides all the functionality of the PAPI. |
| Furthermore, via <a href="../processor/Punctuator.html#punctuate(long)"><code>Punctuator.punctuate(long)</code></a> the processing progress can |
| be observed and additional periodic actions can be performed. |
| <p> |
| In order for the transformer to use state stores, the stores must be added to the topology and connected to the |
| transformer using at least one of two strategies (though it's not required to connect global state stores; read-only |
| access to global state stores is available by default). |
| <p> |
| The first strategy is to manually add the <a href="../state/StoreBuilder.html" title="interface in org.apache.kafka.streams.state"><code>StoreBuilder</code></a>s via <a href="../Topology.html#addStateStore(org.apache.kafka.streams.state.StoreBuilder,java.lang.String...)"><code>Topology.addStateStore(StoreBuilder, String...)</code></a>, |
| and specify the store names via <code>stateStoreNames</code> so they will be connected to the transformer. |
| <pre><code> |
| // create store |
| StoreBuilder<KeyValueStore<String,String>> keyValueStoreBuilder = |
| Stores.keyValueStoreBuilder(Stores.persistentKeyValueStore("myValueTransformState"), |
| Serdes.String(), |
| Serdes.String()); |
| // add store |
| builder.addStateStore(keyValueStoreBuilder); |
| |
| KStream outputStream = inputStream.flatTransformValues(new ValueTransformerWithKeySupplier() { |
| public ValueTransformerWithKey get() { |
| return new MyValueTransformerWithKey(); |
| } |
| }, "myValueTransformState"); |
| </code></pre> |
| The second strategy is for the given <a href="ValueTransformerSupplier.html" title="interface in org.apache.kafka.streams.kstream"><code>ValueTransformerSupplier</code></a> to implement <a href="../processor/ConnectedStoreProvider.html#stores()"><code>ConnectedStoreProvider.stores()</code></a>, |
| which provides the <a href="../state/StoreBuilder.html" title="interface in org.apache.kafka.streams.state"><code>StoreBuilder</code></a>s to be automatically added to the topology and connected to the transformer. |
| <pre><code> |
| class MyValueTransformerWithKeySupplier implements ValueTransformerWithKeySupplier { |
| // supply transformer |
| ValueTransformerWithKey get() { |
| return new MyValueTransformerWithKey(); |
| } |
| |
| // provide store(s) that will be added and connected to the associated transformer |
| // the store name from the builder ("myValueTransformState") is used to access the store later via the ProcessorContext |
| Set<StoreBuilder> stores() { |
| StoreBuilder<KeyValueStore<String, String>> keyValueStoreBuilder = |
| Stores.keyValueStoreBuilder(Stores.persistentKeyValueStore("myValueTransformState"), |
| Serdes.String(), |
| Serdes.String()); |
| return Collections.singleton(keyValueStoreBuilder); |
| } |
| } |
| |
| ... |
| |
| KStream outputStream = inputStream.flatTransformValues(new MyValueTransformerWithKey()); |
| </code></pre> |
| <p> |
| With either strategy, within the <a href="ValueTransformerWithKey.html" title="interface in org.apache.kafka.streams.kstream"><code>ValueTransformerWithKey</code></a>, the state is obtained via the <a href="../processor/api/ProcessorContext.html" title="interface in org.apache.kafka.streams.processor.api"><code>ProcessorContext</code></a>. |
| To trigger periodic actions via <a href="../processor/Punctuator.html#punctuate(long)"><code>punctuate()</code></a>, |
| a schedule must be registered. |
| The <a href="ValueTransformerWithKey.html" title="interface in org.apache.kafka.streams.kstream"><code>ValueTransformerWithKey</code></a> must return an <a href="https://docs.oracle.com/en/java/javase/17/docs/api/java.base/java/lang/Iterable.html" title="class or interface in java.lang" class="external-link"><code>Iterable</code></a> type (e.g., any |
| <a href="https://docs.oracle.com/en/java/javase/17/docs/api/java.base/java/util/Collection.html" title="class or interface in java.util" class="external-link"><code>Collection</code></a> type) in <a href="ValueTransformerWithKey.html#transform(K,V)"><code>transform()</code></a>. |
| If the return value of <a href="ValueTransformerWithKey.html#transform(K,V)"><code>ValueTransformerWithKey#transform()</code></a> |
| is an empty <a href="https://docs.oracle.com/en/java/javase/17/docs/api/java.base/java/lang/Iterable.html" title="class or interface in java.lang" class="external-link"><code>Iterable</code></a> or <code>null</code>, no records are emitted. |
| In contrast to <a href="#transform(org.apache.kafka.streams.kstream.TransformerSupplier,java.lang.String...)"><code>transform()</code></a> and |
| <a href="#flatTransform(org.apache.kafka.streams.kstream.TransformerSupplier,java.lang.String...)"><code>flatTransform()</code></a>, no additional <a href="../KeyValue.html" title="class in org.apache.kafka.streams"><code>KeyValue</code></a> pairs |
| can be emitted via |
| <a href="../processor/ProcessorContext.html#forward(K,V)"><code>ProcessorContext.forward()</code></a>. |
| A <a href="../errors/StreamsException.html" title="class in org.apache.kafka.streams.errors"><code>StreamsException</code></a> is thrown if the <a href="ValueTransformerWithKey.html" title="interface in org.apache.kafka.streams.kstream"><code>ValueTransformerWithKey</code></a> tries |
| to emit a <a href="../KeyValue.html" title="class in org.apache.kafka.streams"><code>KeyValue</code></a> pair. |
| <pre><code> |
| class MyValueTransformerWithKey implements ValueTransformerWithKey { |
| private StateStore state; |
| |
| void init(ProcessorContext context) { |
| this.state = context.getStateStore("myValueTransformState"); |
| // punctuate each second, can access this.state |
| context.schedule(Duration.ofSeconds(1), PunctuationType.WALL_CLOCK_TIME, new Punctuator(..)); |
| } |
| |
| Iterable<NewValueType> transform(K readOnlyKey, V value) { |
| // can access this.state and use read-only key |
| List<NewValueType> result = new ArrayList<>(); |
| for (int i = 0; i < 3; i++) { |
| result.add(new NewValueType(readOnlyKey)); |
| } |
| return result; // values |
| } |
| |
| void close() { |
| // can access this.state |
| } |
| } |
| </code></pre> |
| Even if any upstream operation was key-changing, no auto-repartition is triggered. |
| If repartitioning is required, a call to <a href="#repartition()"><code>repartition()</code></a> should be performed before |
| <code>flatTransformValues()</code>. |
| <p> |
| Note that the key is read-only and should not be modified, as this can lead to corrupt partitioning. |
| So, setting a new value preserves data co-location with respect to the key. |
| Thus, <em>no</em> internal data redistribution is required if a key based operator (like an aggregation or join) |
| is applied to the result <code>KStream</code>. (cf. <a href="#flatTransform(org.apache.kafka.streams.kstream.TransformerSupplier,java.lang.String...)"><code>flatTransform()</code></a>)</div> |
| <dl class="notes"> |
| <dt>Type Parameters:</dt> |
| <dd><code>VR</code> - the value type of the result stream</dd> |
| <dt>Parameters:</dt> |
| <dd><code>valueTransformerSupplier</code> - an instance of <a href="ValueTransformerWithKeySupplier.html" title="interface in org.apache.kafka.streams.kstream"><code>ValueTransformerWithKeySupplier</code></a> that generates a newly constructed <a href="ValueTransformerWithKey.html" title="interface in org.apache.kafka.streams.kstream"><code>ValueTransformerWithKey</code></a> |
| The supplier should always generate a new instance. Creating a single <a href="ValueTransformerWithKey.html" title="interface in org.apache.kafka.streams.kstream"><code>ValueTransformerWithKey</code></a> object |
| and returning the same object reference in <a href="ValueTransformerWithKey.html" title="interface in org.apache.kafka.streams.kstream"><code>ValueTransformerWithKey</code></a> is a |
| violation of the supplier pattern and leads to runtime exceptions.</dd> |
| <dd><code>named</code> - a <a href="Named.html" title="class in org.apache.kafka.streams.kstream"><code>Named</code></a> config used to name the processor in the topology</dd> |
| <dd><code>stateStoreNames</code> - the names of the state stores used by the processor; not required if the supplier |
| implements <a href="../processor/ConnectedStoreProvider.html#stores()"><code>ConnectedStoreProvider.stores()</code></a></dd> |
| <dt>Returns:</dt> |
| <dd>a <code>KStream</code> that contains more or less records with unmodified key and new values (possibly of |
| different type)</dd> |
| <dt>See Also:</dt> |
| <dd> |
| <ul class="see-list-long"> |
| <li><a href="#mapValues(org.apache.kafka.streams.kstream.ValueMapper)"><code>mapValues(ValueMapper)</code></a></li> |
| <li><a href="#mapValues(org.apache.kafka.streams.kstream.ValueMapperWithKey)"><code>mapValues(ValueMapperWithKey)</code></a></li> |
| <li><a href="#transform(org.apache.kafka.streams.kstream.TransformerSupplier,java.lang.String...)"><code>transform(TransformerSupplier, String...)</code></a></li> |
| <li><a href="#flatTransform(org.apache.kafka.streams.kstream.TransformerSupplier,java.lang.String...)"><code>flatTransform(TransformerSupplier, String...)</code></a></li> |
| </ul> |
| </dd> |
| </dl> |
| </section> |
| </li> |
| <li> |
| <section class="detail" id="process(org.apache.kafka.streams.processor.ProcessorSupplier,java.lang.String...)"> |
| <h3>process</h3> |
| <div class="member-signature"><span class="annotations"><a href="https://docs.oracle.com/en/java/javase/17/docs/api/java.base/java/lang/Deprecated.html" title="class or interface in java.lang" class="external-link">@Deprecated</a> |
| </span><span class="return-type">void</span> <span class="element-name">process</span><wbr><span class="parameters">(<a href="../processor/ProcessorSupplier.html" title="interface in org.apache.kafka.streams.processor">ProcessorSupplier</a><? super <a href="KStream.html" title="type parameter in KStream">K</a>,<wbr>? super <a href="KStream.html" title="type parameter in KStream">V</a>> processorSupplier, |
| <a href="https://docs.oracle.com/en/java/javase/17/docs/api/java.base/java/lang/String.html" title="class or interface in java.lang" class="external-link">String</a>... stateStoreNames)</span></div> |
| <div class="deprecation-block"><span class="deprecated-label">Deprecated.</span> |
| <div class="deprecation-comment">Since 3.0. Use <a href="#process(org.apache.kafka.streams.processor.api.ProcessorSupplier,java.lang.String...)"><code>process(org.apache.kafka.streams.processor.api.ProcessorSupplier, java.lang.String...)</code></a> instead.</div> |
| </div> |
| <div class="block">Process all records in this stream, one record at a time, by applying a |
| <a href="../processor/Processor.html" title="interface in org.apache.kafka.streams.processor"><code>Processor</code></a> (provided by the given |
| <a href="../processor/ProcessorSupplier.html" title="interface in org.apache.kafka.streams.processor"><code>ProcessorSupplier</code></a>). |
| Attaching a state store makes this a stateful record-by-record operation (cf. <a href="#foreach(org.apache.kafka.streams.kstream.ForeachAction)"><code>foreach(ForeachAction)</code></a>). |
| If you choose not to attach one, this operation is similar to the stateless <a href="#foreach(org.apache.kafka.streams.kstream.ForeachAction)"><code>foreach(ForeachAction)</code></a> |
| but allows access to the <code>ProcessorContext</code> and record metadata. |
| This is essentially mixing the Processor API into the DSL, and provides all the functionality of the PAPI. |
| Furthermore, via <a href="../processor/Punctuator.html#punctuate(long)"><code>Punctuator.punctuate(long)</code></a> the processing progress |
| can be observed and additional periodic actions can be performed. |
| Note that this is a terminal operation that returns void. |
| <p> |
| In order for the processor to use state stores, the stores must be added to the topology and connected to the |
| processor using at least one of two strategies (though it's not required to connect global state stores; read-only |
| access to global state stores is available by default). |
| <p> |
| The first strategy is to manually add the <a href="../state/StoreBuilder.html" title="interface in org.apache.kafka.streams.state"><code>StoreBuilder</code></a>s via <a href="../Topology.html#addStateStore(org.apache.kafka.streams.state.StoreBuilder,java.lang.String...)"><code>Topology.addStateStore(StoreBuilder, String...)</code></a>, |
| and specify the store names via <code>stateStoreNames</code> so they will be connected to the processor. |
| <pre><code> |
| // create store |
| StoreBuilder<KeyValueStore<String,String>> keyValueStoreBuilder = |
| Stores.keyValueStoreBuilder(Stores.persistentKeyValueStore("myProcessorState"), |
| Serdes.String(), |
| Serdes.String()); |
| // add store |
| builder.addStateStore(keyValueStoreBuilder); |
| |
| KStream outputStream = inputStream.processor(new ProcessorSupplier() { |
| public Processor get() { |
| return new MyProcessor(); |
| } |
| }, "myProcessorState"); |
| </code></pre> |
| The second strategy is for the given <a href="../processor/ProcessorSupplier.html" title="interface in org.apache.kafka.streams.processor"><code>ProcessorSupplier</code></a> |
| to implement <a href="../processor/ConnectedStoreProvider.html#stores()"><code>ConnectedStoreProvider.stores()</code></a>, |
| which provides the <a href="../state/StoreBuilder.html" title="interface in org.apache.kafka.streams.state"><code>StoreBuilder</code></a>s to be automatically added to the topology and connected to the processor. |
| <pre><code> |
| class MyProcessorSupplier implements ProcessorSupplier { |
| // supply processor |
| Processor get() { |
| return new MyProcessor(); |
| } |
| |
| // provide store(s) that will be added and connected to the associated processor |
| // the store name from the builder ("myProcessorState") is used to access the store later via the ProcessorContext |
| Set<StoreBuilder> stores() { |
| StoreBuilder<KeyValueStore<String, String>> keyValueStoreBuilder = |
| Stores.keyValueStoreBuilder(Stores.persistentKeyValueStore("myProcessorState"), |
| Serdes.String(), |
| Serdes.String()); |
| return Collections.singleton(keyValueStoreBuilder); |
| } |
| } |
| |
| ... |
| |
| KStream outputStream = inputStream.process(new MyProcessorSupplier()); |
| </code></pre> |
| <p> |
| With either strategy, within the <a href="../processor/Processor.html" title="interface in org.apache.kafka.streams.processor"><code>Processor</code></a>, |
| the state is obtained via the <a href="../processor/ProcessorContext.html" title="interface in org.apache.kafka.streams.processor"><code>ProcessorContext</code></a>. |
| To trigger periodic actions via <a href="../processor/Punctuator.html#punctuate(long)"><code>punctuate()</code></a>, |
| a schedule must be registered. |
| <pre><code> |
| class MyProcessor implements Processor { |
| private StateStore state; |
| |
| void init(ProcessorContext context) { |
| this.state = context.getStateStore("myProcessorState"); |
| // punctuate each second, can access this.state |
| context.schedule(Duration.ofSeconds(1), PunctuationType.WALL_CLOCK_TIME, new Punctuator(..)); |
| } |
| |
| void process(K key, V value) { |
| // can access this.state |
| } |
| |
| void close() { |
| // can access this.state |
| } |
| } |
| </code></pre> |
| Even if any upstream operation was key-changing, no auto-repartition is triggered. |
| If repartitioning is required, a call to <a href="#repartition()"><code>repartition()</code></a> should be performed before <code>process()</code>.</div> |
| <dl class="notes"> |
| <dt>Parameters:</dt> |
| <dd><code>processorSupplier</code> - an instance of <a href="../processor/ProcessorSupplier.html" title="interface in org.apache.kafka.streams.processor"><code>ProcessorSupplier</code></a> |
| that generates a newly constructed <a href="../processor/Processor.html" title="interface in org.apache.kafka.streams.processor"><code>Processor</code></a> |
| The supplier should always generate a new instance. Creating a single |
| <a href="../processor/Processor.html" title="interface in org.apache.kafka.streams.processor"><code>Processor</code></a> object |
| and returning the same object reference in |
| <a href="../processor/ProcessorSupplier.html#get()"><code>ProcessorSupplier.get()</code></a> is a |
| violation of the supplier pattern and leads to runtime exceptions.</dd> |
| <dd><code>stateStoreNames</code> - the names of the state stores used by the processor; not required if the supplier |
| implements <a href="../processor/ConnectedStoreProvider.html#stores()"><code>ConnectedStoreProvider.stores()</code></a></dd> |
| <dt>See Also:</dt> |
| <dd> |
| <ul class="see-list-long"> |
| <li><a href="#foreach(org.apache.kafka.streams.kstream.ForeachAction)"><code>foreach(ForeachAction)</code></a></li> |
| <li><a href="#transform(org.apache.kafka.streams.kstream.TransformerSupplier,java.lang.String...)"><code>transform(TransformerSupplier, String...)</code></a></li> |
| </ul> |
| </dd> |
| </dl> |
| </section> |
| </li> |
| <li> |
| <section class="detail" id="process(org.apache.kafka.streams.processor.api.ProcessorSupplier,java.lang.String...)"> |
| <h3>process</h3> |
| <div class="member-signature"><span class="return-type">void</span> <span class="element-name">process</span><wbr><span class="parameters">(<a href="../processor/api/ProcessorSupplier.html" title="interface in org.apache.kafka.streams.processor.api">ProcessorSupplier</a><? super <a href="KStream.html" title="type parameter in KStream">K</a>,<wbr>? super <a href="KStream.html" title="type parameter in KStream">V</a>,<wbr><a href="https://docs.oracle.com/en/java/javase/17/docs/api/java.base/java/lang/Void.html" title="class or interface in java.lang" class="external-link">Void</a>,<wbr><a href="https://docs.oracle.com/en/java/javase/17/docs/api/java.base/java/lang/Void.html" title="class or interface in java.lang" class="external-link">Void</a>> processorSupplier, |
| <a href="https://docs.oracle.com/en/java/javase/17/docs/api/java.base/java/lang/String.html" title="class or interface in java.lang" class="external-link">String</a>... stateStoreNames)</span></div> |
| <div class="block">Process all records in this stream, one record at a time, by applying a <a href="../processor/api/Processor.html" title="interface in org.apache.kafka.streams.processor.api"><code>Processor</code></a> (provided by the given |
| <a href="../processor/api/ProcessorSupplier.html" title="interface in org.apache.kafka.streams.processor.api"><code>ProcessorSupplier</code></a>). |
| Attaching a state store makes this a stateful record-by-record operation (cf. <a href="#foreach(org.apache.kafka.streams.kstream.ForeachAction)"><code>foreach(ForeachAction)</code></a>). |
| If you choose not to attach one, this operation is similar to the stateless <a href="#foreach(org.apache.kafka.streams.kstream.ForeachAction)"><code>foreach(ForeachAction)</code></a> |
| but allows access to the <code>ProcessorContext</code> and record metadata. |
| This is essentially mixing the Processor API into the DSL, and provides all the functionality of the PAPI. |
| Furthermore, via <a href="../processor/Punctuator.html#punctuate(long)"><code>Punctuator.punctuate(long)</code></a> the processing progress |
| can be observed and additional periodic actions can be performed. |
| Note that this is a terminal operation that returns void. |
| <p> |
| In order for the processor to use state stores, the stores must be added to the topology and connected to the |
| processor using at least one of two strategies (though it's not required to connect global state stores; read-only |
| access to global state stores is available by default). |
| <p> |
| The first strategy is to manually add the <a href="../state/StoreBuilder.html" title="interface in org.apache.kafka.streams.state"><code>StoreBuilder</code></a>s via <a href="../Topology.html#addStateStore(org.apache.kafka.streams.state.StoreBuilder,java.lang.String...)"><code>Topology.addStateStore(StoreBuilder, String...)</code></a>, |
| and specify the store names via <code>stateStoreNames</code> so they will be connected to the processor. |
| <pre><code> |
| // create store |
| StoreBuilder<KeyValueStore<String,String>> keyValueStoreBuilder = |
| Stores.keyValueStoreBuilder(Stores.persistentKeyValueStore("myProcessorState"), |
| Serdes.String(), |
| Serdes.String()); |
| // add store |
| builder.addStateStore(keyValueStoreBuilder); |
| |
| KStream outputStream = inputStream.processor(new ProcessorSupplier() { |
| public Processor get() { |
| return new MyProcessor(); |
| } |
| }, "myProcessorState"); |
| </code></pre> |
| The second strategy is for the given <a href="../processor/api/ProcessorSupplier.html" title="interface in org.apache.kafka.streams.processor.api"><code>ProcessorSupplier</code></a> to implement <a href="../processor/ConnectedStoreProvider.html#stores()"><code>ConnectedStoreProvider.stores()</code></a>, |
| which provides the <a href="../state/StoreBuilder.html" title="interface in org.apache.kafka.streams.state"><code>StoreBuilder</code></a>s to be automatically added to the topology and connected to the processor. |
| <pre><code> |
| class MyProcessorSupplier implements ProcessorSupplier { |
| // supply processor |
| Processor get() { |
| return new MyProcessor(); |
| } |
| |
| // provide store(s) that will be added and connected to the associated processor |
| // the store name from the builder ("myProcessorState") is used to access the store later via the ProcessorContext |
| Set<StoreBuilder> stores() { |
| StoreBuilder<KeyValueStore<String, String>> keyValueStoreBuilder = |
| Stores.keyValueStoreBuilder(Stores.persistentKeyValueStore("myProcessorState"), |
| Serdes.String(), |
| Serdes.String()); |
| return Collections.singleton(keyValueStoreBuilder); |
| } |
| } |
| |
| ... |
| |
| KStream outputStream = inputStream.process(new MyProcessorSupplier()); |
| </code></pre> |
| <p> |
| With either strategy, within the <a href="../processor/api/Processor.html" title="interface in org.apache.kafka.streams.processor.api"><code>Processor</code></a>, the state is obtained via the <a href="../processor/api/ProcessorContext.html" title="interface in org.apache.kafka.streams.processor.api"><code>ProcessorContext</code></a>. |
| To trigger periodic actions via <a href="../processor/Punctuator.html#punctuate(long)"><code>punctuate()</code></a>, |
| a schedule must be registered. |
| <pre><code> |
| class MyProcessor implements Processor { |
| private StateStore state; |
| |
| void init(ProcessorContext context) { |
| this.state = context.getStateStore("myProcessorState"); |
| // punctuate each second, can access this.state |
| context.schedule(Duration.ofSeconds(1), PunctuationType.WALL_CLOCK_TIME, new Punctuator(..)); |
| } |
| |
| void process(K key, V value) { |
| // can access this.state |
| } |
| |
| void close() { |
| // can access this.state |
| } |
| } |
| </code></pre> |
| Even if any upstream operation was key-changing, no auto-repartition is triggered. |
| If repartitioning is required, a call to <a href="#repartition()"><code>repartition()</code></a> should be performed before <code>process()</code>.</div> |
| <dl class="notes"> |
| <dt>Parameters:</dt> |
| <dd><code>processorSupplier</code> - an instance of <a href="../processor/api/ProcessorSupplier.html" title="interface in org.apache.kafka.streams.processor.api"><code>ProcessorSupplier</code></a> that generates a newly constructed <a href="../processor/api/Processor.html" title="interface in org.apache.kafka.streams.processor.api"><code>Processor</code></a> |
| The supplier should always generate a new instance. Creating a single <a href="../processor/api/Processor.html" title="interface in org.apache.kafka.streams.processor.api"><code>Processor</code></a> object |
| and returning the same object reference in <a href="../processor/api/ProcessorSupplier.html#get()"><code>ProcessorSupplier.get()</code></a> is a |
| violation of the supplier pattern and leads to runtime exceptions.</dd> |
| <dd><code>stateStoreNames</code> - the names of the state stores used by the processor; not required if the supplier |
| implements <a href="../processor/ConnectedStoreProvider.html#stores()"><code>ConnectedStoreProvider.stores()</code></a></dd> |
| <dt>See Also:</dt> |
| <dd> |
| <ul class="see-list-long"> |
| <li><a href="#foreach(org.apache.kafka.streams.kstream.ForeachAction)"><code>foreach(ForeachAction)</code></a></li> |
| <li><a href="#transform(org.apache.kafka.streams.kstream.TransformerSupplier,java.lang.String...)"><code>transform(TransformerSupplier, String...)</code></a></li> |
| </ul> |
| </dd> |
| </dl> |
| </section> |
| </li> |
| <li> |
| <section class="detail" id="process(org.apache.kafka.streams.processor.ProcessorSupplier,org.apache.kafka.streams.kstream.Named,java.lang.String...)"> |
| <h3>process</h3> |
| <div class="member-signature"><span class="annotations"><a href="https://docs.oracle.com/en/java/javase/17/docs/api/java.base/java/lang/Deprecated.html" title="class or interface in java.lang" class="external-link">@Deprecated</a> |
| </span><span class="return-type">void</span> <span class="element-name">process</span><wbr><span class="parameters">(<a href="../processor/ProcessorSupplier.html" title="interface in org.apache.kafka.streams.processor">ProcessorSupplier</a><? super <a href="KStream.html" title="type parameter in KStream">K</a>,<wbr>? super <a href="KStream.html" title="type parameter in KStream">V</a>> processorSupplier, |
| <a href="Named.html" title="class in org.apache.kafka.streams.kstream">Named</a> named, |
| <a href="https://docs.oracle.com/en/java/javase/17/docs/api/java.base/java/lang/String.html" title="class or interface in java.lang" class="external-link">String</a>... stateStoreNames)</span></div> |
| <div class="deprecation-block"><span class="deprecated-label">Deprecated.</span> |
| <div class="deprecation-comment">Since 3.0. Use <a href="#process(org.apache.kafka.streams.processor.api.ProcessorSupplier,org.apache.kafka.streams.kstream.Named,java.lang.String...)"><code>process(org.apache.kafka.streams.processor.api.ProcessorSupplier, org.apache.kafka.streams.kstream.Named, java.lang.String...)</code></a> instead.</div> |
| </div> |
| <div class="block">Process all records in this stream, one record at a time, by applying a |
| <a href="../processor/Processor.html" title="interface in org.apache.kafka.streams.processor"><code>Processor</code></a> (provided by the given |
| <a href="../processor/ProcessorSupplier.html" title="interface in org.apache.kafka.streams.processor"><code>ProcessorSupplier</code></a>). |
| Attaching a state store makes this a stateful record-by-record operation (cf. <a href="#foreach(org.apache.kafka.streams.kstream.ForeachAction)"><code>foreach(ForeachAction)</code></a>). |
| If you choose not to attach one, this operation is similar to the stateless <a href="#foreach(org.apache.kafka.streams.kstream.ForeachAction)"><code>foreach(ForeachAction)</code></a> |
| but allows access to the <code>ProcessorContext</code> and record metadata. |
| This is essentially mixing the Processor API into the DSL, and provides all the functionality of the PAPI. |
| Furthermore, via <a href="../processor/Punctuator.html#punctuate(long)"><code>Punctuator.punctuate(long)</code></a> the processing progress |
| can be observed and additional periodic actions can be performed. |
| Note that this is a terminal operation that returns void. |
| <p> |
| In order for the processor to use state stores, the stores must be added to the topology and connected to the |
| processor using at least one of two strategies (though it's not required to connect global state stores; read-only |
| access to global state stores is available by default). |
| <p> |
| The first strategy is to manually add the <a href="../state/StoreBuilder.html" title="interface in org.apache.kafka.streams.state"><code>StoreBuilder</code></a>s via <a href="../Topology.html#addStateStore(org.apache.kafka.streams.state.StoreBuilder,java.lang.String...)"><code>Topology.addStateStore(StoreBuilder, String...)</code></a>, |
| and specify the store names via <code>stateStoreNames</code> so they will be connected to the processor. |
| <pre><code> |
| // create store |
| StoreBuilder<KeyValueStore<String,String>> keyValueStoreBuilder = |
| Stores.keyValueStoreBuilder(Stores.persistentKeyValueStore("myProcessorState"), |
| Serdes.String(), |
| Serdes.String()); |
| // add store |
| builder.addStateStore(keyValueStoreBuilder); |
| |
| KStream outputStream = inputStream.processor(new ProcessorSupplier() { |
| public Processor get() { |
| return new MyProcessor(); |
| } |
| }, "myProcessorState"); |
| </code></pre> |
| The second strategy is for the given <a href="../processor/ProcessorSupplier.html" title="interface in org.apache.kafka.streams.processor"><code>ProcessorSupplier</code></a> |
| to implement <a href="../processor/ConnectedStoreProvider.html#stores()"><code>ConnectedStoreProvider.stores()</code></a>, |
| which provides the <a href="../state/StoreBuilder.html" title="interface in org.apache.kafka.streams.state"><code>StoreBuilder</code></a>s to be automatically added to the topology and connected to the processor. |
| <pre><code> |
| class MyProcessorSupplier implements ProcessorSupplier { |
| // supply processor |
| Processor get() { |
| return new MyProcessor(); |
| } |
| |
| // provide store(s) that will be added and connected to the associated processor |
| // the store name from the builder ("myProcessorState") is used to access the store later via the ProcessorContext |
| Set<StoreBuilder> stores() { |
| StoreBuilder<KeyValueStore<String, String>> keyValueStoreBuilder = |
| Stores.keyValueStoreBuilder(Stores.persistentKeyValueStore("myProcessorState"), |
| Serdes.String(), |
| Serdes.String()); |
| return Collections.singleton(keyValueStoreBuilder); |
| } |
| } |
| |
| ... |
| |
| KStream outputStream = inputStream.process(new MyProcessorSupplier()); |
| </code></pre> |
| <p> |
| With either strategy, within the <a href="../processor/Processor.html" title="interface in org.apache.kafka.streams.processor"><code>Processor</code></a>, |
| the state is obtained via the <a href="../processor/ProcessorContext.html" title="interface in org.apache.kafka.streams.processor"><code>ProcessorContext</code></a>. |
| To trigger periodic actions via <a href="../processor/Punctuator.html#punctuate(long)"><code>punctuate()</code></a>, |
| a schedule must be registered. |
| <pre><code> |
| class MyProcessor implements Processor { |
| private StateStore state; |
| |
| void init(ProcessorContext context) { |
| this.state = context.getStateStore("myProcessorState"); |
| // punctuate each second, can access this.state |
| context.schedule(Duration.ofSeconds(1), PunctuationType.WALL_CLOCK_TIME, new Punctuator(..)); |
| } |
| |
| void process(K key, V value) { |
| // can access this.state |
| } |
| |
| void close() { |
| // can access this.state |
| } |
| } |
| </code></pre> |
| Even if any upstream operation was key-changing, no auto-repartition is triggered. |
| If repartitioning is required, a call to <a href="#repartition()"><code>repartition()</code></a> should be performed before <code>process()</code>.</div> |
| <dl class="notes"> |
| <dt>Parameters:</dt> |
| <dd><code>processorSupplier</code> - an instance of <a href="../processor/ProcessorSupplier.html" title="interface in org.apache.kafka.streams.processor"><code>ProcessorSupplier</code></a> |
| that generates a newly constructed <a href="../processor/Processor.html" title="interface in org.apache.kafka.streams.processor"><code>Processor</code></a> |
| The supplier should always generate a new instance. Creating a single |
| <a href="../processor/Processor.html" title="interface in org.apache.kafka.streams.processor"><code>Processor</code></a> object |
| and returning the same object reference in |
| <a href="../processor/ProcessorSupplier.html#get()"><code>ProcessorSupplier.get()</code></a> is a |
| violation of the supplier pattern and leads to runtime exceptions.</dd> |
| <dd><code>named</code> - a <a href="Named.html" title="class in org.apache.kafka.streams.kstream"><code>Named</code></a> config used to name the processor in the topology</dd> |
| <dd><code>stateStoreNames</code> - the names of the state store used by the processor</dd> |
| <dt>See Also:</dt> |
| <dd> |
| <ul class="see-list-long"> |
| <li><a href="#foreach(org.apache.kafka.streams.kstream.ForeachAction)"><code>foreach(ForeachAction)</code></a></li> |
| <li><a href="#transform(org.apache.kafka.streams.kstream.TransformerSupplier,java.lang.String...)"><code>transform(TransformerSupplier, String...)</code></a></li> |
| </ul> |
| </dd> |
| </dl> |
| </section> |
| </li> |
| <li> |
| <section class="detail" id="process(org.apache.kafka.streams.processor.api.ProcessorSupplier,org.apache.kafka.streams.kstream.Named,java.lang.String...)"> |
| <h3>process</h3> |
| <div class="member-signature"><span class="return-type">void</span> <span class="element-name">process</span><wbr><span class="parameters">(<a href="../processor/api/ProcessorSupplier.html" title="interface in org.apache.kafka.streams.processor.api">ProcessorSupplier</a><? super <a href="KStream.html" title="type parameter in KStream">K</a>,<wbr>? super <a href="KStream.html" title="type parameter in KStream">V</a>,<wbr><a href="https://docs.oracle.com/en/java/javase/17/docs/api/java.base/java/lang/Void.html" title="class or interface in java.lang" class="external-link">Void</a>,<wbr><a href="https://docs.oracle.com/en/java/javase/17/docs/api/java.base/java/lang/Void.html" title="class or interface in java.lang" class="external-link">Void</a>> processorSupplier, |
| <a href="Named.html" title="class in org.apache.kafka.streams.kstream">Named</a> named, |
| <a href="https://docs.oracle.com/en/java/javase/17/docs/api/java.base/java/lang/String.html" title="class or interface in java.lang" class="external-link">String</a>... stateStoreNames)</span></div> |
| <div class="block">Process all records in this stream, one record at a time, by applying a <a href="../processor/api/Processor.html" title="interface in org.apache.kafka.streams.processor.api"><code>Processor</code></a> (provided by the given |
| <a href="../processor/api/ProcessorSupplier.html" title="interface in org.apache.kafka.streams.processor.api"><code>ProcessorSupplier</code></a>). |
| Attaching a state store makes this a stateful record-by-record operation (cf. <a href="#foreach(org.apache.kafka.streams.kstream.ForeachAction)"><code>foreach(ForeachAction)</code></a>). |
| If you choose not to attach one, this operation is similar to the stateless <a href="#foreach(org.apache.kafka.streams.kstream.ForeachAction)"><code>foreach(ForeachAction)</code></a> |
| but allows access to the <code>ProcessorContext</code> and record metadata. |
| This is essentially mixing the Processor API into the DSL, and provides all the functionality of the PAPI. |
| Furthermore, via <a href="../processor/Punctuator.html#punctuate(long)"><code>Punctuator.punctuate(long)</code></a> the processing progress |
| can be observed and additional periodic actions can be performed. |
| Note that this is a terminal operation that returns void. |
| <p> |
| In order for the processor to use state stores, the stores must be added to the topology and connected to the |
| processor using at least one of two strategies (though it's not required to connect global state stores; read-only |
| access to global state stores is available by default). |
| <p> |
| The first strategy is to manually add the <a href="../state/StoreBuilder.html" title="interface in org.apache.kafka.streams.state"><code>StoreBuilder</code></a>s via <a href="../Topology.html#addStateStore(org.apache.kafka.streams.state.StoreBuilder,java.lang.String...)"><code>Topology.addStateStore(StoreBuilder, String...)</code></a>, |
| and specify the store names via <code>stateStoreNames</code> so they will be connected to the processor. |
| <pre><code> |
| // create store |
| StoreBuilder<KeyValueStore<String,String>> keyValueStoreBuilder = |
| Stores.keyValueStoreBuilder(Stores.persistentKeyValueStore("myProcessorState"), |
| Serdes.String(), |
| Serdes.String()); |
| // add store |
| builder.addStateStore(keyValueStoreBuilder); |
| |
| KStream outputStream = inputStream.processor(new ProcessorSupplier() { |
| public Processor get() { |
| return new MyProcessor(); |
| } |
| }, "myProcessorState"); |
| </code></pre> |
| The second strategy is for the given <a href="../processor/api/ProcessorSupplier.html" title="interface in org.apache.kafka.streams.processor.api"><code>ProcessorSupplier</code></a> to implement <a href="../processor/ConnectedStoreProvider.html#stores()"><code>ConnectedStoreProvider.stores()</code></a>, |
| which provides the <a href="../state/StoreBuilder.html" title="interface in org.apache.kafka.streams.state"><code>StoreBuilder</code></a>s to be automatically added to the topology and connected to the processor. |
| <pre><code> |
| class MyProcessorSupplier implements ProcessorSupplier { |
| // supply processor |
| Processor get() { |
| return new MyProcessor(); |
| } |
| |
| // provide store(s) that will be added and connected to the associated processor |
| // the store name from the builder ("myProcessorState") is used to access the store later via the ProcessorContext |
| Set<StoreBuilder> stores() { |
| StoreBuilder<KeyValueStore<String, String>> keyValueStoreBuilder = |
| Stores.keyValueStoreBuilder(Stores.persistentKeyValueStore("myProcessorState"), |
| Serdes.String(), |
| Serdes.String()); |
| return Collections.singleton(keyValueStoreBuilder); |
| } |
| } |
| |
| ... |
| |
| KStream outputStream = inputStream.process(new MyProcessorSupplier()); |
| </code></pre> |
| <p> |
| With either strategy, within the <a href="../processor/api/Processor.html" title="interface in org.apache.kafka.streams.processor.api"><code>Processor</code></a>, the state is obtained via the <a href="../processor/api/ProcessorContext.html" title="interface in org.apache.kafka.streams.processor.api"><code>ProcessorContext</code></a>. |
| To trigger periodic actions via <a href="../processor/Punctuator.html#punctuate(long)"><code>punctuate()</code></a>, |
| a schedule must be registered. |
| <pre><code> |
| class MyProcessor implements Processor { |
| private StateStore state; |
| |
| void init(ProcessorContext context) { |
| this.state = context.getStateStore("myProcessorState"); |
| // punctuate each second, can access this.state |
| context.schedule(Duration.ofSeconds(1), PunctuationType.WALL_CLOCK_TIME, new Punctuator(..)); |
| } |
| |
| void process(K key, V value) { |
| // can access this.state |
| } |
| |
| void close() { |
| // can access this.state |
| } |
| } |
| </code></pre> |
| Even if any upstream operation was key-changing, no auto-repartition is triggered. |
| If repartitioning is required, a call to <a href="#repartition()"><code>repartition()</code></a> should be performed before <code>process()</code>.</div> |
| <dl class="notes"> |
| <dt>Parameters:</dt> |
| <dd><code>processorSupplier</code> - an instance of <a href="../processor/api/ProcessorSupplier.html" title="interface in org.apache.kafka.streams.processor.api"><code>ProcessorSupplier</code></a> that generates a newly constructed <a href="../processor/api/Processor.html" title="interface in org.apache.kafka.streams.processor.api"><code>Processor</code></a> |
| The supplier should always generate a new instance. Creating a single <a href="../processor/api/Processor.html" title="interface in org.apache.kafka.streams.processor.api"><code>Processor</code></a> object |
| and returning the same object reference in <a href="../processor/api/ProcessorSupplier.html#get()"><code>ProcessorSupplier.get()</code></a> is a |
| violation of the supplier pattern and leads to runtime exceptions.</dd> |
| <dd><code>named</code> - a <a href="Named.html" title="class in org.apache.kafka.streams.kstream"><code>Named</code></a> config used to name the processor in the topology</dd> |
| <dd><code>stateStoreNames</code> - the names of the state store used by the processor</dd> |
| <dt>See Also:</dt> |
| <dd> |
| <ul class="see-list-long"> |
| <li><a href="#foreach(org.apache.kafka.streams.kstream.ForeachAction)"><code>foreach(ForeachAction)</code></a></li> |
| <li><a href="#transform(org.apache.kafka.streams.kstream.TransformerSupplier,java.lang.String...)"><code>transform(TransformerSupplier, String...)</code></a></li> |
| </ul> |
| </dd> |
| </dl> |
| </section> |
| </li> |
| </ul> |
| </section> |
| </li> |
| </ul> |
| </section> |
| <!-- ========= END OF CLASS DATA ========= --> |
| </main> |
| </div> |
| </div> |
| </body> |
| </html> |
