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StreamPipes</span><meta itemprop="position" content="1"></li><li itemscope="" itemprop="itemListElement" itemtype="https://schema.org/ListItem" class="breadcrumbs__item breadcrumbs__item--active"><span class="breadcrumbs__link" itemprop="name">SDK: Stream Requirements</span><meta itemprop="position" content="2"></li></ul></nav><span class="theme-doc-version-badge badge badge--secondary">Version: 0.92.0</span><div class="tocCollapsible_ETCw theme-doc-toc-mobile tocMobile_ITEo"><button type="button" class="clean-btn tocCollapsibleButton_TO0P">On this page</button></div><div class="theme-doc-markdown markdown"><header><h1>SDK Guide: Stream Requirements</h1></header><h2 class="anchor anchorWithStickyNavbar_LWe7" id="introduction">Introduction<a href="#introduction" class="hash-link" aria-label="Direct link to Introduction" title="Direct link to Introduction"></a></h2><p>Data processors and data sinks can define <code>StreamRequirements</code>. Stream requirements allow pipeline elements to express requirements on an incoming event stream that are needed for the element to work properly.
 Once users create pipelines in the StreamPipes Pipeline Editor, these requirements are verified against the connected event stream.
 By using this feature, StreamPipes ensures that only pipeline elements can be connected that are syntactically and semantically valid.</p><p>This guide covers the creation of stream requirements. Before reading this section, we recommend that you make yourself familiar with the SDK guide on <a href="/docs/0.92.0/dev-guide-sdk-guide-processors/">data processors</a> and <a href="/docs/0.92.0/dev-guide-sdk-guide-sinks/">data sinks</a>.</p><div class="admonition tip"><div class="admonition-title">Code on Github</div><p>For all examples, the code can be found on <a href="https://www.github.com/apache/streampipes-examples/tree/dev/streampipes-pipeline-elements-examples-processors-jvm/src/main/java/org/apache/streampipes/pe/examples/jvm/requirements/" target="_blank" rel="noopener noreferrer">Github</a>.</p></div><h2 class="anchor anchorWithStickyNavbar_LWe7" id="the-streamrequirementsbuilder">The StreamRequirementsBuilder<a href="#the-streamrequirementsbuilder" class="hash-link" aria-label="Direct link to The StreamRequirementsBuilder" title="Direct link to The StreamRequirementsBuilder"></a></h2><p>Stream requirements can be defined in the <code>declareModel</code> method of the pipeline element class. Start with a method body like this:</p><div class="language-java codeBlockContainer_Ckt0 theme-code-block" style="--prism-color:#bfc7d5;--prism-background-color:#292d3e"><div class="codeBlockContent_biex"><pre tabindex="0" class="prism-code language-java codeBlock_bY9V thin-scrollbar"><code class="codeBlockLines_e6Vv"><span class="token-line" style="color:#bfc7d5"><span class="token plain" style="display:inline-block"></span><br></span><span class="token-line" style="color:#bfc7d5"><span class="token plain"></span><span class="token annotation punctuation" style="color:rgb(199, 146, 234)">@Override</span><span class="token plain"></span><br></span><span class="token-line" style="color:#bfc7d5"><span class="token plain">  </span><span class="token keyword" style="font-style:italic">public</span><span class="token plain"> </span><span class="token class-name" style="color:rgb(255, 203, 107)">DataProcessorDescription</span><span class="token plain"> </span><span class="token function" style="color:rgb(130, 170, 255)">declareModel</span><span class="token punctuation" style="color:rgb(199, 146, 234)">(</span><span class="token punctuation" style="color:rgb(199, 146, 234)">)</span><span class="token plain"> </span><span class="token punctuation" style="color:rgb(199, 146, 234)">{</span><span class="token plain"></span><br></span><span class="token-line" style="color:#bfc7d5"><span class="token plain">    </span><span class="token keyword" style="font-style:italic">return</span><span class="token plain"> </span><span class="token class-name" style="color:rgb(255, 203, 107)">ProcessingElementBuilder</span><span class="token punctuation" style="color:rgb(199, 146, 234)">.</span><span class="token function" style="color:rgb(130, 170, 255)">create</span><span class="token punctuation" style="color:rgb(199, 146, 234)">(</span><span class="token constant" style="color:rgb(130, 170, 255)">ID</span><span class="token punctuation" style="color:rgb(199, 146, 234)">,</span><span class="token plain"> </span><span class="token constant" style="color:rgb(130, 170, 255)">PIPELINE_ELEMENT_NAME</span><span class="token punctuation" style="color:rgb(199, 146, 234)">,</span><span class="token plain"> </span><span class="token constant" style="color:rgb(130, 170, 255)">DESCRIPTION</span><span class="token punctuation" style="color:rgb(199, 146, 234)">)</span><span class="token plain"></span><br></span><span class="token-line" style="color:#bfc7d5"><span class="token plain">            </span><span class="token punctuation" style="color:rgb(199, 146, 234)">.</span><span class="token function" style="color:rgb(130, 170, 255)">requiredStream</span><span class="token punctuation" style="color:rgb(199, 146, 234)">(</span><span class="token class-name" style="color:rgb(255, 203, 107)">StreamRequirementsBuilder</span><span class="token punctuation" style="color:rgb(199, 146, 234)">.</span><span class="token plain"></span><br></span><span class="token-line" style="color:#bfc7d5"><span class="token plain">                    </span><span class="token function" style="color:rgb(130, 170, 255)">create</span><span class="token punctuation" style="color:rgb(199, 146, 234)">(</span><span class="token punctuation" style="color:rgb(199, 146, 234)">)</span><span class="token plain"></span><br></span><span class="token-line" style="color:#bfc7d5"><span class="token plain" style="display:inline-block"></span><br></span><span class="token-line" style="color:#bfc7d5"><span class="token plain">                    </span><span class="token punctuation" style="color:rgb(199, 146, 234)">.</span><span class="token function" style="color:rgb(130, 170, 255)">build</span><span class="token punctuation" style="color:rgb(199, 146, 234)">(</span><span class="token punctuation" style="color:rgb(199, 146, 234)">)</span><span class="token punctuation" style="color:rgb(199, 146, 234)">)</span><span class="token plain"></span><br></span><span class="token-line" style="color:#bfc7d5"><span class="token plain" style="display:inline-block"></span><br></span><span class="token-line" style="color:#bfc7d5"><span class="token plain">            </span><span class="token punctuation" style="color:rgb(199, 146, 234)">.</span><span class="token function" style="color:rgb(130, 170, 255)">supportedProtocols</span><span class="token punctuation" style="color:rgb(199, 146, 234)">(</span><span class="token class-name" style="color:rgb(255, 203, 107)">SupportedProtocols</span><span class="token punctuation" style="color:rgb(199, 146, 234)">.</span><span class="token function" style="color:rgb(130, 170, 255)">kafka</span><span class="token punctuation" style="color:rgb(199, 146, 234)">(</span><span class="token punctuation" style="color:rgb(199, 146, 234)">)</span><span class="token punctuation" style="color:rgb(199, 146, 234)">)</span><span class="token plain"></span><br></span><span class="token-line" style="color:#bfc7d5"><span class="token plain">            </span><span class="token punctuation" style="color:rgb(199, 146, 234)">.</span><span class="token function" style="color:rgb(130, 170, 255)">supportedFormats</span><span class="token punctuation" style="color:rgb(199, 146, 234)">(</span><span class="token class-name" style="color:rgb(255, 203, 107)">SupportedFormats</span><span class="token punctuation" style="color:rgb(199, 146, 234)">.</span><span class="token function" style="color:rgb(130, 170, 255)">jsonFormat</span><span class="token punctuation" style="color:rgb(199, 146, 234)">(</span><span class="token punctuation" style="color:rgb(199, 146, 234)">)</span><span class="token punctuation" style="color:rgb(199, 146, 234)">)</span><span class="token plain"></span><br></span><span class="token-line" style="color:#bfc7d5"><span class="token plain">            </span><span class="token punctuation" style="color:rgb(199, 146, 234)">.</span><span class="token function" style="color:rgb(130, 170, 255)">outputStrategy</span><span class="token punctuation" style="color:rgb(199, 146, 234)">(</span><span class="token class-name" style="color:rgb(255, 203, 107)">OutputStrategies</span><span class="token punctuation" style="color:rgb(199, 146, 234)">.</span><span class="token function" style="color:rgb(130, 170, 255)">keep</span><span class="token punctuation" style="color:rgb(199, 146, 234)">(</span><span class="token punctuation" style="color:rgb(199, 146, 234)">)</span><span class="token punctuation" style="color:rgb(199, 146, 234)">)</span><span class="token plain"></span><br></span><span class="token-line" style="color:#bfc7d5"><span class="token plain" style="display:inline-block"></span><br></span><span class="token-line" style="color:#bfc7d5"><span class="token plain">            </span><span class="token punctuation" style="color:rgb(199, 146, 234)">.</span><span class="token function" style="color:rgb(130, 170, 255)">build</span><span class="token punctuation" style="color:rgb(199, 146, 234)">(</span><span class="token punctuation" style="color:rgb(199, 146, 234)">)</span><span class="token punctuation" style="color:rgb(199, 146, 234)">;</span><span class="token plain"></span><br></span><span class="token-line" style="color:#bfc7d5"><span class="token plain">  </span><span class="token punctuation" style="color:rgb(199, 146, 234)">}</span><br></span></code></pre><div class="buttonGroup__atx"><button type="button" aria-label="Copy code to clipboard" title="Copy" class="clean-btn"><span class="copyButtonIcons_eSgA" aria-hidden="true"><svg viewBox="0 0 24 24" class="copyButtonIcon_y97N"><path fill="currentColor" d="M19,21H8V7H19M19,5H8A2,2 0 0,0 6,7V21A2,2 0 0,0 8,23H19A2,2 0 0,0 21,21V7A2,2 0 0,0 19,5M16,1H4A2,2 0 0,0 2,3V17H4V3H16V1Z"></path></svg><svg viewBox="0 0 24 24" class="copyButtonSuccessIcon_LjdS"><path fill="currentColor" d="M21,7L9,19L3.5,13.5L4.91,12.09L9,16.17L19.59,5.59L21,7Z"></path></svg></span></button></div></div></div><p>The <code>StreamRequirementsBuilder</code> class provides methods to add stream requirements to a pipeline element.</p><h2 class="anchor anchorWithStickyNavbar_LWe7" id="requirements-on-primitive-fields">Requirements on primitive fields<a href="#requirements-on-primitive-fields" class="hash-link" aria-label="Direct link to Requirements on primitive fields" title="Direct link to Requirements on primitive fields"></a></h2><p>As a very first example, let&#x27;s assume we would like to create a data processor that filters numerical values that are above a given threshold.
 Consequently, any data stream that is connected to the filter processor needs to provide a numerical value.</p><p>The stream requirement would be assigned as follows:</p><div class="language-java codeBlockContainer_Ckt0 theme-code-block" style="--prism-color:#bfc7d5;--prism-background-color:#292d3e"><div class="codeBlockContent_biex"><pre tabindex="0" class="prism-code language-java codeBlock_bY9V thin-scrollbar"><code class="codeBlockLines_e6Vv"><span class="token-line" style="color:#bfc7d5"><span class="token annotation punctuation" style="color:rgb(199, 146, 234)">@Override</span><span class="token plain"></span><br></span><span class="token-line" style="color:#bfc7d5"><span class="token plain">  </span><span class="token keyword" style="font-style:italic">public</span><span class="token plain"> </span><span class="token class-name" style="color:rgb(255, 203, 107)">DataProcessorDescription</span><span class="token plain"> </span><span class="token function" style="color:rgb(130, 170, 255)">declareModel</span><span class="token punctuation" style="color:rgb(199, 146, 234)">(</span><span class="token punctuation" style="color:rgb(199, 146, 234)">)</span><span class="token plain"> </span><span class="token punctuation" style="color:rgb(199, 146, 234)">{</span><span class="token plain"></span><br></span><span class="token-line" style="color:#bfc7d5"><span class="token plain">    </span><span class="token keyword" style="font-style:italic">return</span><span class="token plain"> </span><span class="token class-name" style="color:rgb(255, 203, 107)">ProcessingElementBuilder</span><span class="token punctuation" style="color:rgb(199, 146, 234)">.</span><span class="token function" style="color:rgb(130, 170, 255)">create</span><span class="token punctuation" style="color:rgb(199, 146, 234)">(</span><span class="token constant" style="color:rgb(130, 170, 255)">ID</span><span class="token punctuation" style="color:rgb(199, 146, 234)">,</span><span class="token plain"> </span><span class="token constant" style="color:rgb(130, 170, 255)">PIPELINE_ELEMENT_NAME</span><span class="token punctuation" style="color:rgb(199, 146, 234)">,</span><span class="token plain"> </span><span class="token constant" style="color:rgb(130, 170, 255)">DESCRIPTION</span><span class="token punctuation" style="color:rgb(199, 146, 234)">)</span><span class="token plain"></span><br></span><span class="token-line" style="color:#bfc7d5"><span class="token plain">            </span><span class="token punctuation" style="color:rgb(199, 146, 234)">.</span><span class="token function" style="color:rgb(130, 170, 255)">requiredStream</span><span class="token punctuation" style="color:rgb(199, 146, 234)">(</span><span class="token class-name" style="color:rgb(255, 203, 107)">StreamRequirementsBuilder</span><span class="token plain"></span><br></span><span class="token-line" style="color:#bfc7d5"><span class="token plain">                    </span><span class="token punctuation" style="color:rgb(199, 146, 234)">.</span><span class="token function" style="color:rgb(130, 170, 255)">create</span><span class="token punctuation" style="color:rgb(199, 146, 234)">(</span><span class="token punctuation" style="color:rgb(199, 146, 234)">)</span><span class="token plain"></span><br></span><span class="token-line" style="color:#bfc7d5"><span class="token plain">                    </span><span class="token punctuation" style="color:rgb(199, 146, 234)">.</span><span class="token function" style="color:rgb(130, 170, 255)">requiredProperty</span><span class="token punctuation" style="color:rgb(199, 146, 234)">(</span><span class="token class-name" style="color:rgb(255, 203, 107)">EpRequirements</span><span class="token punctuation" style="color:rgb(199, 146, 234)">.</span><span class="token function" style="color:rgb(130, 170, 255)">numberReq</span><span class="token punctuation" style="color:rgb(199, 146, 234)">(</span><span class="token punctuation" style="color:rgb(199, 146, 234)">)</span><span class="token punctuation" style="color:rgb(199, 146, 234)">)</span><span class="token plain"></span><br></span><span class="token-line" style="color:#bfc7d5"><span class="token plain">                    </span><span class="token punctuation" style="color:rgb(199, 146, 234)">.</span><span class="token function" style="color:rgb(130, 170, 255)">build</span><span class="token punctuation" style="color:rgb(199, 146, 234)">(</span><span class="token punctuation" style="color:rgb(199, 146, 234)">)</span><span class="token punctuation" style="color:rgb(199, 146, 234)">)</span><span class="token plain"></span><br></span><span class="token-line" style="color:#bfc7d5"><span class="token plain" style="display:inline-block"></span><br></span><span class="token-line" style="color:#bfc7d5"><span class="token plain">            </span><span class="token punctuation" style="color:rgb(199, 146, 234)">.</span><span class="token function" style="color:rgb(130, 170, 255)">supportedProtocols</span><span class="token punctuation" style="color:rgb(199, 146, 234)">(</span><span class="token class-name" style="color:rgb(255, 203, 107)">SupportedProtocols</span><span class="token punctuation" style="color:rgb(199, 146, 234)">.</span><span class="token function" style="color:rgb(130, 170, 255)">kafka</span><span class="token punctuation" style="color:rgb(199, 146, 234)">(</span><span class="token punctuation" style="color:rgb(199, 146, 234)">)</span><span class="token punctuation" style="color:rgb(199, 146, 234)">)</span><span class="token plain"></span><br></span><span class="token-line" style="color:#bfc7d5"><span class="token plain">            </span><span class="token punctuation" style="color:rgb(199, 146, 234)">.</span><span class="token function" style="color:rgb(130, 170, 255)">supportedFormats</span><span class="token punctuation" style="color:rgb(199, 146, 234)">(</span><span class="token class-name" style="color:rgb(255, 203, 107)">SupportedFormats</span><span class="token punctuation" style="color:rgb(199, 146, 234)">.</span><span class="token function" style="color:rgb(130, 170, 255)">jsonFormat</span><span class="token punctuation" style="color:rgb(199, 146, 234)">(</span><span class="token punctuation" style="color:rgb(199, 146, 234)">)</span><span class="token punctuation" style="color:rgb(199, 146, 234)">)</span><span class="token plain"></span><br></span><span class="token-line" style="color:#bfc7d5"><span class="token plain">            </span><span class="token punctuation" style="color:rgb(199, 146, 234)">.</span><span class="token function" style="color:rgb(130, 170, 255)">outputStrategy</span><span class="token punctuation" style="color:rgb(199, 146, 234)">(</span><span class="token class-name" style="color:rgb(255, 203, 107)">OutputStrategies</span><span class="token punctuation" style="color:rgb(199, 146, 234)">.</span><span class="token function" style="color:rgb(130, 170, 255)">keep</span><span class="token punctuation" style="color:rgb(199, 146, 234)">(</span><span class="token punctuation" style="color:rgb(199, 146, 234)">)</span><span class="token punctuation" style="color:rgb(199, 146, 234)">)</span><span class="token plain"></span><br></span><span class="token-line" style="color:#bfc7d5"><span class="token plain" style="display:inline-block"></span><br></span><span class="token-line" style="color:#bfc7d5"><span class="token plain">            </span><span class="token punctuation" style="color:rgb(199, 146, 234)">.</span><span class="token function" style="color:rgb(130, 170, 255)">build</span><span class="token punctuation" style="color:rgb(199, 146, 234)">(</span><span class="token punctuation" style="color:rgb(199, 146, 234)">)</span><span class="token punctuation" style="color:rgb(199, 146, 234)">;</span><span class="token plain"></span><br></span><span class="token-line" style="color:#bfc7d5"><span class="token plain">  </span><span class="token punctuation" style="color:rgb(199, 146, 234)">}</span><br></span></code></pre><div class="buttonGroup__atx"><button type="button" aria-label="Copy code to clipboard" title="Copy" class="clean-btn"><span class="copyButtonIcons_eSgA" aria-hidden="true"><svg viewBox="0 0 24 24" class="copyButtonIcon_y97N"><path fill="currentColor" d="M19,21H8V7H19M19,5H8A2,2 0 0,0 6,7V21A2,2 0 0,0 8,23H19A2,2 0 0,0 21,21V7A2,2 0 0,0 19,5M16,1H4A2,2 0 0,0 2,3V17H4V3H16V1Z"></path></svg><svg viewBox="0 0 24 24" class="copyButtonSuccessIcon_LjdS"><path fill="currentColor" d="M21,7L9,19L3.5,13.5L4.91,12.09L9,16.17L19.59,5.59L21,7Z"></path></svg></span></button></div></div></div><p>Note the line starting with <code>requiredProperty</code>, which requires any stream to provide a datatype of type <code>number</code>.</p><p>In many cases, you&#x27;ll want to let the user select a specific field from a data stream from all available fields that match the specified requirement. For that, you simply use the method <code>requiredPropertyWithUnaryMapping</code> as follows:</p><div class="language-java codeBlockContainer_Ckt0 theme-code-block" style="--prism-color:#bfc7d5;--prism-background-color:#292d3e"><div class="codeBlockContent_biex"><pre tabindex="0" class="prism-code language-java codeBlock_bY9V thin-scrollbar"><code class="codeBlockLines_e6Vv"><span class="token-line" style="color:#bfc7d5"><span class="token annotation punctuation" style="color:rgb(199, 146, 234)">@Override</span><span class="token plain"></span><br></span><span class="token-line" style="color:#bfc7d5"><span class="token plain">  </span><span class="token keyword" style="font-style:italic">public</span><span class="token plain"> </span><span class="token class-name" style="color:rgb(255, 203, 107)">DataProcessorDescription</span><span class="token plain"> </span><span class="token function" style="color:rgb(130, 170, 255)">declareModel</span><span class="token punctuation" style="color:rgb(199, 146, 234)">(</span><span class="token punctuation" style="color:rgb(199, 146, 234)">)</span><span class="token plain"> </span><span class="token punctuation" style="color:rgb(199, 146, 234)">{</span><span class="token plain"></span><br></span><span class="token-line" style="color:#bfc7d5"><span class="token plain">    </span><span class="token keyword" style="font-style:italic">return</span><span class="token plain"> </span><span class="token class-name" style="color:rgb(255, 203, 107)">ProcessingElementBuilder</span><span class="token punctuation" style="color:rgb(199, 146, 234)">.</span><span class="token function" style="color:rgb(130, 170, 255)">create</span><span class="token punctuation" style="color:rgb(199, 146, 234)">(</span><span class="token constant" style="color:rgb(130, 170, 255)">ID</span><span class="token punctuation" style="color:rgb(199, 146, 234)">,</span><span class="token plain"> </span><span class="token constant" style="color:rgb(130, 170, 255)">PIPELINE_ELEMENT_NAME</span><span class="token punctuation" style="color:rgb(199, 146, 234)">,</span><span class="token plain"> </span><span class="token constant" style="color:rgb(130, 170, 255)">DESCRIPTION</span><span class="token punctuation" style="color:rgb(199, 146, 234)">)</span><span class="token plain"></span><br></span><span class="token-line" style="color:#bfc7d5"><span class="token plain">            </span><span class="token punctuation" style="color:rgb(199, 146, 234)">.</span><span class="token function" style="color:rgb(130, 170, 255)">requiredStream</span><span class="token punctuation" style="color:rgb(199, 146, 234)">(</span><span class="token class-name" style="color:rgb(255, 203, 107)">StreamRequirementsBuilder</span><span class="token plain"></span><br></span><span class="token-line" style="color:#bfc7d5"><span class="token plain">                    </span><span class="token punctuation" style="color:rgb(199, 146, 234)">.</span><span class="token function" style="color:rgb(130, 170, 255)">create</span><span class="token punctuation" style="color:rgb(199, 146, 234)">(</span><span class="token punctuation" style="color:rgb(199, 146, 234)">)</span><span class="token plain"></span><br></span><span class="token-line" style="color:#bfc7d5"><span class="token plain">                    </span><span class="token punctuation" style="color:rgb(199, 146, 234)">.</span><span class="token function" style="color:rgb(130, 170, 255)">requiredPropertyWithUnaryMapping</span><span class="token punctuation" style="color:rgb(199, 146, 234)">(</span><span class="token class-name" style="color:rgb(255, 203, 107)">EpRequirements</span><span class="token punctuation" style="color:rgb(199, 146, 234)">.</span><span class="token function" style="color:rgb(130, 170, 255)">numberReq</span><span class="token punctuation" style="color:rgb(199, 146, 234)">(</span><span class="token punctuation" style="color:rgb(199, 146, 234)">)</span><span class="token punctuation" style="color:rgb(199, 146, 234)">,</span><span class="token plain"></span><br></span><span class="token-line" style="color:#bfc7d5"><span class="token plain">                    </span><span class="token class-name" style="color:rgb(255, 203, 107)">Labels</span><span class="token punctuation" style="color:rgb(199, 146, 234)">.</span><span class="token function" style="color:rgb(130, 170, 255)">from</span><span class="token punctuation" style="color:rgb(199, 146, 234)">(</span><span class="token string" style="color:rgb(195, 232, 141)">&quot;number-mapping&quot;</span><span class="token punctuation" style="color:rgb(199, 146, 234)">,</span><span class="token plain"> </span><span class="token string" style="color:rgb(195, 232, 141)">&quot;The value that should be filtered&quot;</span><span class="token punctuation" style="color:rgb(199, 146, 234)">,</span><span class="token plain"> </span><span class="token string" style="color:rgb(195, 232, 141)">&quot;&quot;</span><span class="token punctuation" style="color:rgb(199, 146, 234)">)</span><span class="token punctuation" style="color:rgb(199, 146, 234)">,</span><span class="token plain"> </span><span class="token class-name" style="color:rgb(255, 203, 107)">PropertyScope</span><span class="token punctuation" style="color:rgb(199, 146, 234)">.</span><span class="token constant" style="color:rgb(130, 170, 255)">NONE</span><span class="token punctuation" style="color:rgb(199, 146, 234)">)</span><span class="token plain"></span><br></span><span class="token-line" style="color:#bfc7d5"><span class="token plain">                    </span><span class="token punctuation" style="color:rgb(199, 146, 234)">.</span><span class="token function" style="color:rgb(130, 170, 255)">build</span><span class="token punctuation" style="color:rgb(199, 146, 234)">(</span><span class="token punctuation" style="color:rgb(199, 146, 234)">)</span><span class="token punctuation" style="color:rgb(199, 146, 234)">)</span><span class="token plain"></span><br></span><span class="token-line" style="color:#bfc7d5"><span class="token plain" style="display:inline-block"></span><br></span><span class="token-line" style="color:#bfc7d5"><span class="token plain">            </span><span class="token punctuation" style="color:rgb(199, 146, 234)">.</span><span class="token function" style="color:rgb(130, 170, 255)">supportedProtocols</span><span class="token punctuation" style="color:rgb(199, 146, 234)">(</span><span class="token class-name" style="color:rgb(255, 203, 107)">SupportedProtocols</span><span class="token punctuation" style="color:rgb(199, 146, 234)">.</span><span class="token function" style="color:rgb(130, 170, 255)">kafka</span><span class="token punctuation" style="color:rgb(199, 146, 234)">(</span><span class="token punctuation" style="color:rgb(199, 146, 234)">)</span><span class="token punctuation" style="color:rgb(199, 146, 234)">)</span><span class="token plain"></span><br></span><span class="token-line" style="color:#bfc7d5"><span class="token plain">            </span><span class="token punctuation" style="color:rgb(199, 146, 234)">.</span><span class="token function" style="color:rgb(130, 170, 255)">supportedFormats</span><span class="token punctuation" style="color:rgb(199, 146, 234)">(</span><span class="token class-name" style="color:rgb(255, 203, 107)">SupportedFormats</span><span class="token punctuation" style="color:rgb(199, 146, 234)">.</span><span class="token function" style="color:rgb(130, 170, 255)">jsonFormat</span><span class="token punctuation" style="color:rgb(199, 146, 234)">(</span><span class="token punctuation" style="color:rgb(199, 146, 234)">)</span><span class="token punctuation" style="color:rgb(199, 146, 234)">)</span><span class="token plain"></span><br></span><span class="token-line" style="color:#bfc7d5"><span class="token plain">            </span><span class="token punctuation" style="color:rgb(199, 146, 234)">.</span><span class="token function" style="color:rgb(130, 170, 255)">outputStrategy</span><span class="token punctuation" style="color:rgb(199, 146, 234)">(</span><span class="token class-name" style="color:rgb(255, 203, 107)">OutputStrategies</span><span class="token punctuation" style="color:rgb(199, 146, 234)">.</span><span class="token function" style="color:rgb(130, 170, 255)">keep</span><span class="token punctuation" style="color:rgb(199, 146, 234)">(</span><span class="token punctuation" style="color:rgb(199, 146, 234)">)</span><span class="token punctuation" style="color:rgb(199, 146, 234)">)</span><span class="token plain"></span><br></span><span class="token-line" style="color:#bfc7d5"><span class="token plain" style="display:inline-block"></span><br></span><span class="token-line" style="color:#bfc7d5"><span class="token plain">            </span><span class="token punctuation" style="color:rgb(199, 146, 234)">.</span><span class="token function" style="color:rgb(130, 170, 255)">build</span><span class="token punctuation" style="color:rgb(199, 146, 234)">(</span><span class="token punctuation" style="color:rgb(199, 146, 234)">)</span><span class="token punctuation" style="color:rgb(199, 146, 234)">;</span><span class="token plain"></span><br></span><span class="token-line" style="color:#bfc7d5"><span class="token plain">  </span><span class="token punctuation" style="color:rgb(199, 146, 234)">}</span><br></span></code></pre><div class="buttonGroup__atx"><button type="button" aria-label="Copy code to clipboard" title="Copy" class="clean-btn"><span class="copyButtonIcons_eSgA" aria-hidden="true"><svg viewBox="0 0 24 24" class="copyButtonIcon_y97N"><path fill="currentColor" d="M19,21H8V7H19M19,5H8A2,2 0 0,0 6,7V21A2,2 0 0,0 8,23H19A2,2 0 0,0 21,21V7A2,2 0 0,0 19,5M16,1H4A2,2 0 0,0 2,3V17H4V3H16V1Z"></path></svg><svg viewBox="0 0 24 24" class="copyButtonSuccessIcon_LjdS"><path fill="currentColor" d="M21,7L9,19L3.5,13.5L4.91,12.09L9,16.17L19.59,5.59L21,7Z"></path></svg></span></button></div></div></div><p>See also the developer guide on <a href="/docs/0.92.0/extend-sdk-stream-requirements/extend-sdk-static-properties/">static properties</a> to better understand the usage of <code>MappingProperties</code>.</p><p>Requirements on primitive fields can be specified for all common datatypes:</p><div class="language-java codeBlockContainer_Ckt0 theme-code-block" style="--prism-color:#bfc7d5;--prism-background-color:#292d3e"><div class="codeBlockContent_biex"><pre tabindex="0" class="prism-code language-java codeBlock_bY9V thin-scrollbar"><code class="codeBlockLines_e6Vv"><span class="token-line" style="color:#bfc7d5"><span class="token plain"> </span><span class="token annotation punctuation" style="color:rgb(199, 146, 234)">@Override</span><span class="token plain"></span><br></span><span class="token-line" style="color:#bfc7d5"><span class="token plain">  </span><span class="token keyword" style="font-style:italic">public</span><span class="token plain"> </span><span class="token class-name" style="color:rgb(255, 203, 107)">DataProcessorDescription</span><span class="token plain"> </span><span class="token function" style="color:rgb(130, 170, 255)">declareModel</span><span class="token punctuation" style="color:rgb(199, 146, 234)">(</span><span class="token punctuation" style="color:rgb(199, 146, 234)">)</span><span class="token plain"> </span><span class="token punctuation" style="color:rgb(199, 146, 234)">{</span><span class="token plain"></span><br></span><span class="token-line" style="color:#bfc7d5"><span class="token plain">    </span><span class="token keyword" style="font-style:italic">return</span><span class="token plain"> </span><span class="token class-name" style="color:rgb(255, 203, 107)">ProcessingElementBuilder</span><span class="token punctuation" style="color:rgb(199, 146, 234)">.</span><span class="token function" style="color:rgb(130, 170, 255)">create</span><span class="token punctuation" style="color:rgb(199, 146, 234)">(</span><span class="token string" style="color:rgb(195, 232, 141)">&quot;org.streampipes.examples.requirements&quot;</span><span class="token plain"> </span><span class="token operator" style="color:rgb(137, 221, 255)">+</span><span class="token plain"></span><br></span><span class="token-line" style="color:#bfc7d5"><span class="token plain">            </span><span class="token string" style="color:rgb(195, 232, 141)">&quot;.simple&quot;</span><span class="token punctuation" style="color:rgb(199, 146, 234)">,</span><span class="token plain"> </span><span class="token string" style="color:rgb(195, 232, 141)">&quot;Simple requirements specification examples&quot;</span><span class="token punctuation" style="color:rgb(199, 146, 234)">,</span><span class="token plain"> </span><span class="token string" style="color:rgb(195, 232, 141)">&quot;&quot;</span><span class="token punctuation" style="color:rgb(199, 146, 234)">)</span><span class="token plain"></span><br></span><span class="token-line" style="color:#bfc7d5"><span class="token plain">            </span><span class="token punctuation" style="color:rgb(199, 146, 234)">.</span><span class="token function" style="color:rgb(130, 170, 255)">requiredStream</span><span class="token punctuation" style="color:rgb(199, 146, 234)">(</span><span class="token class-name" style="color:rgb(255, 203, 107)">StreamRequirementsBuilder</span><span class="token punctuation" style="color:rgb(199, 146, 234)">.</span><span class="token plain"></span><br></span><span class="token-line" style="color:#bfc7d5"><span class="token plain">                    </span><span class="token function" style="color:rgb(130, 170, 255)">create</span><span class="token punctuation" style="color:rgb(199, 146, 234)">(</span><span class="token punctuation" style="color:rgb(199, 146, 234)">)</span><span class="token plain"></span><br></span><span class="token-line" style="color:#bfc7d5"><span class="token plain">                    </span><span class="token punctuation" style="color:rgb(199, 146, 234)">.</span><span class="token function" style="color:rgb(130, 170, 255)">requiredProperty</span><span class="token punctuation" style="color:rgb(199, 146, 234)">(</span><span class="token class-name" style="color:rgb(255, 203, 107)">EpRequirements</span><span class="token punctuation" style="color:rgb(199, 146, 234)">.</span><span class="token function" style="color:rgb(130, 170, 255)">numberReq</span><span class="token punctuation" style="color:rgb(199, 146, 234)">(</span><span class="token punctuation" style="color:rgb(199, 146, 234)">)</span><span class="token punctuation" style="color:rgb(199, 146, 234)">)</span><span class="token plain"> </span><span class="token comment" style="color:rgb(105, 112, 152);font-style:italic">// any number</span><span class="token plain"></span><br></span><span class="token-line" style="color:#bfc7d5"><span class="token plain">                    </span><span class="token punctuation" style="color:rgb(199, 146, 234)">.</span><span class="token function" style="color:rgb(130, 170, 255)">requiredProperty</span><span class="token punctuation" style="color:rgb(199, 146, 234)">(</span><span class="token class-name" style="color:rgb(255, 203, 107)">EpRequirements</span><span class="token punctuation" style="color:rgb(199, 146, 234)">.</span><span class="token function" style="color:rgb(130, 170, 255)">doubleReq</span><span class="token punctuation" style="color:rgb(199, 146, 234)">(</span><span class="token punctuation" style="color:rgb(199, 146, 234)">)</span><span class="token punctuation" style="color:rgb(199, 146, 234)">)</span><span class="token plain"> </span><span class="token comment" style="color:rgb(105, 112, 152);font-style:italic">// any field of type double</span><span class="token plain"></span><br></span><span class="token-line" style="color:#bfc7d5"><span class="token plain">                    </span><span class="token punctuation" style="color:rgb(199, 146, 234)">.</span><span class="token function" style="color:rgb(130, 170, 255)">requiredProperty</span><span class="token punctuation" style="color:rgb(199, 146, 234)">(</span><span class="token class-name" style="color:rgb(255, 203, 107)">EpRequirements</span><span class="token punctuation" style="color:rgb(199, 146, 234)">.</span><span class="token function" style="color:rgb(130, 170, 255)">booleanReq</span><span class="token punctuation" style="color:rgb(199, 146, 234)">(</span><span class="token punctuation" style="color:rgb(199, 146, 234)">)</span><span class="token punctuation" style="color:rgb(199, 146, 234)">)</span><span class="token plain"> </span><span class="token comment" style="color:rgb(105, 112, 152);font-style:italic">// any field of type boolean</span><span class="token plain"></span><br></span><span class="token-line" style="color:#bfc7d5"><span class="token plain">                    </span><span class="token punctuation" style="color:rgb(199, 146, 234)">.</span><span class="token function" style="color:rgb(130, 170, 255)">requiredProperty</span><span class="token punctuation" style="color:rgb(199, 146, 234)">(</span><span class="token class-name" style="color:rgb(255, 203, 107)">EpRequirements</span><span class="token punctuation" style="color:rgb(199, 146, 234)">.</span><span class="token function" style="color:rgb(130, 170, 255)">integerReq</span><span class="token punctuation" style="color:rgb(199, 146, 234)">(</span><span class="token punctuation" style="color:rgb(199, 146, 234)">)</span><span class="token punctuation" style="color:rgb(199, 146, 234)">)</span><span class="token plain"> </span><span class="token comment" style="color:rgb(105, 112, 152);font-style:italic">// any field of type integer</span><span class="token plain"></span><br></span><span class="token-line" style="color:#bfc7d5"><span class="token plain">                    </span><span class="token punctuation" style="color:rgb(199, 146, 234)">.</span><span class="token function" style="color:rgb(130, 170, 255)">requiredProperty</span><span class="token punctuation" style="color:rgb(199, 146, 234)">(</span><span class="token class-name" style="color:rgb(255, 203, 107)">EpRequirements</span><span class="token punctuation" style="color:rgb(199, 146, 234)">.</span><span class="token function" style="color:rgb(130, 170, 255)">stringReq</span><span class="token punctuation" style="color:rgb(199, 146, 234)">(</span><span class="token punctuation" style="color:rgb(199, 146, 234)">)</span><span class="token punctuation" style="color:rgb(199, 146, 234)">)</span><span class="token plain"> </span><span class="token comment" style="color:rgb(105, 112, 152);font-style:italic">// any field of type string</span><span class="token plain"></span><br></span><span class="token-line" style="color:#bfc7d5"><span class="token plain" style="display:inline-block"></span><br></span><span class="token-line" style="color:#bfc7d5"><span class="token plain">                    </span><span class="token punctuation" style="color:rgb(199, 146, 234)">.</span><span class="token function" style="color:rgb(130, 170, 255)">requiredProperty</span><span class="token punctuation" style="color:rgb(199, 146, 234)">(</span><span class="token class-name" style="color:rgb(255, 203, 107)">EpRequirements</span><span class="token punctuation" style="color:rgb(199, 146, 234)">.</span><span class="token function" style="color:rgb(130, 170, 255)">anyProperty</span><span class="token punctuation" style="color:rgb(199, 146, 234)">(</span><span class="token punctuation" style="color:rgb(199, 146, 234)">)</span><span class="token punctuation" style="color:rgb(199, 146, 234)">)</span><span class="token plain"> </span><span class="token comment" style="color:rgb(105, 112, 152);font-style:italic">// any field allowed (no restriction)</span><span class="token plain"></span><br></span><span class="token-line" style="color:#bfc7d5"><span class="token plain">                    </span><span class="token punctuation" style="color:rgb(199, 146, 234)">.</span><span class="token function" style="color:rgb(130, 170, 255)">requiredProperty</span><span class="token punctuation" style="color:rgb(199, 146, 234)">(</span><span class="token class-name" style="color:rgb(255, 203, 107)">EpRequirements</span><span class="token punctuation" style="color:rgb(199, 146, 234)">.</span><span class="token function" style="color:rgb(130, 170, 255)">timestampReq</span><span class="token punctuation" style="color:rgb(199, 146, 234)">(</span><span class="token punctuation" style="color:rgb(199, 146, 234)">)</span><span class="token punctuation" style="color:rgb(199, 146, 234)">)</span><span class="token plain">  </span><span class="token comment" style="color:rgb(105, 112, 152);font-style:italic">// any timestamp field</span><span class="token plain"></span><br></span><span class="token-line" style="color:#bfc7d5"><span class="token plain">                    </span><span class="token punctuation" style="color:rgb(199, 146, 234)">.</span><span class="token function" style="color:rgb(130, 170, 255)">build</span><span class="token punctuation" style="color:rgb(199, 146, 234)">(</span><span class="token punctuation" style="color:rgb(199, 146, 234)">)</span><span class="token punctuation" style="color:rgb(199, 146, 234)">)</span><span class="token plain"></span><br></span><span class="token-line" style="color:#bfc7d5"><span class="token plain" style="display:inline-block"></span><br></span><span class="token-line" style="color:#bfc7d5"><span class="token plain" style="display:inline-block"></span><br></span><span class="token-line" style="color:#bfc7d5"><span class="token plain">            </span><span class="token punctuation" style="color:rgb(199, 146, 234)">.</span><span class="token function" style="color:rgb(130, 170, 255)">supportedProtocols</span><span class="token punctuation" style="color:rgb(199, 146, 234)">(</span><span class="token class-name" style="color:rgb(255, 203, 107)">SupportedProtocols</span><span class="token punctuation" style="color:rgb(199, 146, 234)">.</span><span class="token function" style="color:rgb(130, 170, 255)">kafka</span><span class="token punctuation" style="color:rgb(199, 146, 234)">(</span><span class="token punctuation" style="color:rgb(199, 146, 234)">)</span><span class="token punctuation" style="color:rgb(199, 146, 234)">)</span><span class="token plain"></span><br></span><span class="token-line" style="color:#bfc7d5"><span class="token plain">            </span><span class="token punctuation" style="color:rgb(199, 146, 234)">.</span><span class="token function" style="color:rgb(130, 170, 255)">supportedFormats</span><span class="token punctuation" style="color:rgb(199, 146, 234)">(</span><span class="token class-name" style="color:rgb(255, 203, 107)">SupportedFormats</span><span class="token punctuation" style="color:rgb(199, 146, 234)">.</span><span class="token function" style="color:rgb(130, 170, 255)">jsonFormat</span><span class="token punctuation" style="color:rgb(199, 146, 234)">(</span><span class="token punctuation" style="color:rgb(199, 146, 234)">)</span><span class="token punctuation" style="color:rgb(199, 146, 234)">)</span><span class="token plain"></span><br></span><span class="token-line" style="color:#bfc7d5"><span class="token plain">            </span><span class="token punctuation" style="color:rgb(199, 146, 234)">.</span><span class="token function" style="color:rgb(130, 170, 255)">outputStrategy</span><span class="token punctuation" style="color:rgb(199, 146, 234)">(</span><span class="token class-name" style="color:rgb(255, 203, 107)">OutputStrategies</span><span class="token punctuation" style="color:rgb(199, 146, 234)">.</span><span class="token function" style="color:rgb(130, 170, 255)">keep</span><span class="token punctuation" style="color:rgb(199, 146, 234)">(</span><span class="token punctuation" style="color:rgb(199, 146, 234)">)</span><span class="token punctuation" style="color:rgb(199, 146, 234)">)</span><span class="token plain"></span><br></span><span class="token-line" style="color:#bfc7d5"><span class="token plain" style="display:inline-block"></span><br></span><span class="token-line" style="color:#bfc7d5"><span class="token plain">            </span><span class="token punctuation" style="color:rgb(199, 146, 234)">.</span><span class="token function" style="color:rgb(130, 170, 255)">build</span><span class="token punctuation" style="color:rgb(199, 146, 234)">(</span><span class="token punctuation" style="color:rgb(199, 146, 234)">)</span><span class="token punctuation" style="color:rgb(199, 146, 234)">;</span><br></span></code></pre><div class="buttonGroup__atx"><button type="button" aria-label="Copy code to clipboard" title="Copy" class="clean-btn"><span class="copyButtonIcons_eSgA" aria-hidden="true"><svg viewBox="0 0 24 24" class="copyButtonIcon_y97N"><path fill="currentColor" d="M19,21H8V7H19M19,5H8A2,2 0 0,0 6,7V21A2,2 0 0,0 8,23H19A2,2 0 0,0 21,21V7A2,2 0 0,0 19,5M16,1H4A2,2 0 0,0 2,3V17H4V3H16V1Z"></path></svg><svg viewBox="0 0 24 24" class="copyButtonSuccessIcon_LjdS"><path fill="currentColor" d="M21,7L9,19L3.5,13.5L4.91,12.09L9,16.17L19.59,5.59L21,7Z"></path></svg></span></button></div></div></div><h3 class="anchor anchorWithStickyNavbar_LWe7" id="specifying-semantics">Specifying semantics<a href="#specifying-semantics" class="hash-link" aria-label="Direct link to Specifying semantics" title="Direct link to Specifying semantics"></a></h3><p>For some algorithms, only specifying the datatype is not sufficient. Let&#x27;s consider a geofencing algorithm that detects the precense some geospatial coordinate (e.g., from a vehicle) within a given location.</p><p>You could specify something like this:</p><div class="language-java codeBlockContainer_Ckt0 theme-code-block" style="--prism-color:#bfc7d5;--prism-background-color:#292d3e"><div class="codeBlockContent_biex"><pre tabindex="0" class="prism-code language-java codeBlock_bY9V thin-scrollbar"><code class="codeBlockLines_e6Vv"><span class="token-line" style="color:#bfc7d5"><span class="token plain">    </span><span class="token class-name" style="color:rgb(255, 203, 107)">StreamRequirementsBuilder</span><span class="token plain"></span><br></span><span class="token-line" style="color:#bfc7d5"><span class="token plain">    </span><span class="token punctuation" style="color:rgb(199, 146, 234)">.</span><span class="token function" style="color:rgb(130, 170, 255)">create</span><span class="token punctuation" style="color:rgb(199, 146, 234)">(</span><span class="token punctuation" style="color:rgb(199, 146, 234)">)</span><span class="token plain"></span><br></span><span class="token-line" style="color:#bfc7d5"><span class="token plain">    </span><span class="token punctuation" style="color:rgb(199, 146, 234)">.</span><span class="token function" style="color:rgb(130, 170, 255)">requiredPropertyWithUnaryMapping</span><span class="token punctuation" style="color:rgb(199, 146, 234)">(</span><span class="token class-name" style="color:rgb(255, 203, 107)">EpRequirements</span><span class="token punctuation" style="color:rgb(199, 146, 234)">.</span><span class="token function" style="color:rgb(130, 170, 255)">doubleEp</span><span class="token punctuation" style="color:rgb(199, 146, 234)">(</span><span class="token punctuation" style="color:rgb(199, 146, 234)">)</span><span class="token punctuation" style="color:rgb(199, 146, 234)">,</span><span class="token plain"> </span><span class="token class-name" style="color:rgb(255, 203, 107)">Labels</span><span class="token punctuation" style="color:rgb(199, 146, 234)">.</span><span class="token function" style="color:rgb(130, 170, 255)">from</span><span class="token punctuation" style="color:rgb(199, 146, 234)">(</span><span class="token string" style="color:rgb(195, 232, 141)">&quot;mapping-latitude&quot;</span><span class="token punctuation" style="color:rgb(199, 146, 234)">,</span><span class="token plain"> </span><span class="token string" style="color:rgb(195, 232, 141)">&quot;Latitude&quot;</span><span class="token punctuation" style="color:rgb(199, 146, 234)">,</span><span class="token plain"> </span><span class="token string" style="color:rgb(195, 232, 141)">&quot;&quot;</span><span class="token punctuation" style="color:rgb(199, 146, 234)">)</span><span class="token punctuation" style="color:rgb(199, 146, 234)">,</span><span class="token plain"> </span><span class="token class-name" style="color:rgb(255, 203, 107)">PropertyScope</span><span class="token punctuation" style="color:rgb(199, 146, 234)">.</span><span class="token constant" style="color:rgb(130, 170, 255)">NONE</span><span class="token punctuation" style="color:rgb(199, 146, 234)">)</span><span class="token plain"></span><br></span><span class="token-line" style="color:#bfc7d5"><span class="token plain">    </span><span class="token punctuation" style="color:rgb(199, 146, 234)">.</span><span class="token function" style="color:rgb(130, 170, 255)">requiredPropertyWithUnaryMapping</span><span class="token punctuation" style="color:rgb(199, 146, 234)">(</span><span class="token class-name" style="color:rgb(255, 203, 107)">EpRequirements</span><span class="token punctuation" style="color:rgb(199, 146, 234)">.</span><span class="token function" style="color:rgb(130, 170, 255)">doubleEp</span><span class="token punctuation" style="color:rgb(199, 146, 234)">(</span><span class="token punctuation" style="color:rgb(199, 146, 234)">)</span><span class="token punctuation" style="color:rgb(199, 146, 234)">,</span><span class="token plain"> </span><span class="token class-name" style="color:rgb(255, 203, 107)">Labels</span><span class="token punctuation" style="color:rgb(199, 146, 234)">.</span><span class="token function" style="color:rgb(130, 170, 255)">from</span><span class="token punctuation" style="color:rgb(199, 146, 234)">(</span><span class="token string" style="color:rgb(195, 232, 141)">&quot;mapping-longitude&quot;</span><span class="token punctuation" style="color:rgb(199, 146, 234)">,</span><span class="token plain"> </span><span class="token string" style="color:rgb(195, 232, 141)">&quot;Longitude&quot;</span><span class="token punctuation" style="color:rgb(199, 146, 234)">,</span><span class="token plain"> </span><span class="token string" style="color:rgb(195, 232, 141)">&quot;&quot;</span><span class="token punctuation" style="color:rgb(199, 146, 234)">)</span><span class="token punctuation" style="color:rgb(199, 146, 234)">,</span><span class="token plain"> </span><span class="token class-name" style="color:rgb(255, 203, 107)">PropertyScope</span><span class="token punctuation" style="color:rgb(199, 146, 234)">.</span><span class="token constant" style="color:rgb(130, 170, 255)">NONE</span><span class="token punctuation" style="color:rgb(199, 146, 234)">)</span><span class="token plain"></span><br></span><span class="token-line" style="color:#bfc7d5"><span class="token plain">    </span><span class="token punctuation" style="color:rgb(199, 146, 234)">.</span><span class="token function" style="color:rgb(130, 170, 255)">build</span><span class="token punctuation" style="color:rgb(199, 146, 234)">(</span><span class="token punctuation" style="color:rgb(199, 146, 234)">)</span><br></span></code></pre><div class="buttonGroup__atx"><button type="button" aria-label="Copy code to clipboard" title="Copy" class="clean-btn"><span class="copyButtonIcons_eSgA" aria-hidden="true"><svg viewBox="0 0 24 24" class="copyButtonIcon_y97N"><path fill="currentColor" d="M19,21H8V7H19M19,5H8A2,2 0 0,0 6,7V21A2,2 0 0,0 8,23H19A2,2 0 0,0 21,21V7A2,2 0 0,0 19,5M16,1H4A2,2 0 0,0 2,3V17H4V3H16V1Z"></path></svg><svg viewBox="0 0 24 24" class="copyButtonSuccessIcon_LjdS"><path fill="currentColor" d="M21,7L9,19L3.5,13.5L4.91,12.09L9,16.17L19.59,5.59L21,7Z"></path></svg></span></button></div></div></div><p>However, this would allow users to create strange pipelines as users could connect any stream containing a double value to our geofencing algorithm.
 To avoid such situations, you can also specify requirements based on the semantics of a field:</p><div class="language-java codeBlockContainer_Ckt0 theme-code-block" style="--prism-color:#bfc7d5;--prism-background-color:#292d3e"><div class="codeBlockContent_biex"><pre tabindex="0" class="prism-code language-java codeBlock_bY9V thin-scrollbar"><code class="codeBlockLines_e6Vv"><span class="token-line" style="color:#bfc7d5"><span class="token plain">    </span><span class="token class-name" style="color:rgb(255, 203, 107)">StreamRequirementsBuilder</span><span class="token plain"></span><br></span><span class="token-line" style="color:#bfc7d5"><span class="token plain">    </span><span class="token punctuation" style="color:rgb(199, 146, 234)">.</span><span class="token function" style="color:rgb(130, 170, 255)">create</span><span class="token punctuation" style="color:rgb(199, 146, 234)">(</span><span class="token punctuation" style="color:rgb(199, 146, 234)">)</span><span class="token plain"></span><br></span><span class="token-line" style="color:#bfc7d5"><span class="token plain">    </span><span class="token punctuation" style="color:rgb(199, 146, 234)">.</span><span class="token function" style="color:rgb(130, 170, 255)">requiredPropertyWithUnaryMapping</span><span class="token punctuation" style="color:rgb(199, 146, 234)">(</span><span class="token class-name" style="color:rgb(255, 203, 107)">EpRequirements</span><span class="token punctuation" style="color:rgb(199, 146, 234)">.</span><span class="token function" style="color:rgb(130, 170, 255)">domainPropertyReq</span><span class="token punctuation" style="color:rgb(199, 146, 234)">(</span><span class="token class-name" style="color:rgb(255, 203, 107)">SO</span><span class="token class-name punctuation" style="color:rgb(199, 146, 234)">.</span><span class="token class-name" style="color:rgb(255, 203, 107)">Latitude</span><span class="token punctuation" style="color:rgb(199, 146, 234)">)</span><span class="token punctuation" style="color:rgb(199, 146, 234)">,</span><span class="token plain"> </span><span class="token class-name" style="color:rgb(255, 203, 107)">Labels</span><span class="token punctuation" style="color:rgb(199, 146, 234)">.</span><span class="token function" style="color:rgb(130, 170, 255)">from</span><span class="token punctuation" style="color:rgb(199, 146, 234)">(</span><span class="token string" style="color:rgb(195, 232, 141)">&quot;mapping-latitude&quot;</span><span class="token punctuation" style="color:rgb(199, 146, 234)">,</span><span class="token plain"> </span><span class="token string" style="color:rgb(195, 232, 141)">&quot;Latitude&quot;</span><span class="token punctuation" style="color:rgb(199, 146, 234)">,</span><span class="token plain"> </span><span class="token string" style="color:rgb(195, 232, 141)">&quot;&quot;</span><span class="token punctuation" style="color:rgb(199, 146, 234)">)</span><span class="token punctuation" style="color:rgb(199, 146, 234)">,</span><span class="token plain"> </span><span class="token class-name" style="color:rgb(255, 203, 107)">PropertyScope</span><span class="token punctuation" style="color:rgb(199, 146, 234)">.</span><span class="token constant" style="color:rgb(130, 170, 255)">NONE</span><span class="token punctuation" style="color:rgb(199, 146, 234)">)</span><span class="token plain"></span><br></span><span class="token-line" style="color:#bfc7d5"><span class="token plain">    </span><span class="token punctuation" style="color:rgb(199, 146, 234)">.</span><span class="token function" style="color:rgb(130, 170, 255)">requiredPropertyWithUnaryMapping</span><span class="token punctuation" style="color:rgb(199, 146, 234)">(</span><span class="token class-name" style="color:rgb(255, 203, 107)">EpRequirements</span><span class="token punctuation" style="color:rgb(199, 146, 234)">.</span><span class="token function" style="color:rgb(130, 170, 255)">domainPropertyReq</span><span class="token punctuation" style="color:rgb(199, 146, 234)">(</span><span class="token class-name" style="color:rgb(255, 203, 107)">SO</span><span class="token class-name punctuation" style="color:rgb(199, 146, 234)">.</span><span class="token class-name" style="color:rgb(255, 203, 107)">Longitude</span><span class="token punctuation" style="color:rgb(199, 146, 234)">)</span><span class="token punctuation" style="color:rgb(199, 146, 234)">,</span><span class="token plain"> </span><span class="token class-name" style="color:rgb(255, 203, 107)">Labels</span><span class="token punctuation" style="color:rgb(199, 146, 234)">.</span><span class="token function" style="color:rgb(130, 170, 255)">from</span><span class="token punctuation" style="color:rgb(199, 146, 234)">(</span><span class="token string" style="color:rgb(195, 232, 141)">&quot;mapping-longitude&quot;</span><span class="token punctuation" style="color:rgb(199, 146, 234)">,</span><span class="token plain"> </span><span class="token string" style="color:rgb(195, 232, 141)">&quot;Longitude&quot;</span><span class="token punctuation" style="color:rgb(199, 146, 234)">,</span><span class="token plain"> </span><span class="token string" style="color:rgb(195, 232, 141)">&quot;&quot;</span><span class="token punctuation" style="color:rgb(199, 146, 234)">)</span><span class="token punctuation" style="color:rgb(199, 146, 234)">,</span><span class="token plain"> </span><span class="token class-name" style="color:rgb(255, 203, 107)">PropertyScope</span><span class="token punctuation" style="color:rgb(199, 146, 234)">.</span><span class="token constant" style="color:rgb(130, 170, 255)">NONE</span><span class="token punctuation" style="color:rgb(199, 146, 234)">)</span><span class="token plain"></span><br></span><span class="token-line" style="color:#bfc7d5"><span class="token plain">    </span><span class="token punctuation" style="color:rgb(199, 146, 234)">.</span><span class="token function" style="color:rgb(130, 170, 255)">build</span><span class="token punctuation" style="color:rgb(199, 146, 234)">(</span><span class="token punctuation" style="color:rgb(199, 146, 234)">)</span><br></span></code></pre><div class="buttonGroup__atx"><button type="button" aria-label="Copy code to clipboard" title="Copy" class="clean-btn"><span class="copyButtonIcons_eSgA" aria-hidden="true"><svg viewBox="0 0 24 24" class="copyButtonIcon_y97N"><path fill="currentColor" d="M19,21H8V7H19M19,5H8A2,2 0 0,0 6,7V21A2,2 0 0,0 8,23H19A2,2 0 0,0 21,21V7A2,2 0 0,0 19,5M16,1H4A2,2 0 0,0 2,3V17H4V3H16V1Z"></path></svg><svg viewBox="0 0 24 24" class="copyButtonSuccessIcon_LjdS"><path fill="currentColor" d="M21,7L9,19L3.5,13.5L4.91,12.09L9,16.17L19.59,5.59L21,7Z"></path></svg></span></button></div></div></div><p>Note that in this case, we make use of Schema.org&#x27;s <code>Latitude</code> concept (<a href="https://schema.org/latitude" target="_blank" rel="noopener noreferrer">https://schema.org/latitude</a>). StreamPipes already includes popular vocabularies for specifying semantics. You are also free to use your own vocabularies.</p><h2 class="anchor anchorWithStickyNavbar_LWe7" id="requirements-on-lists">Requirements on lists<a href="#requirements-on-lists" class="hash-link" aria-label="Direct link to Requirements on lists" title="Direct link to Requirements on lists"></a></h2><p>Similarly to primitive requirements, you can define processors that require data streams with list fields, see the following examples:</p><div class="language-java codeBlockContainer_Ckt0 theme-code-block" style="--prism-color:#bfc7d5;--prism-background-color:#292d3e"><div class="codeBlockContent_biex"><pre tabindex="0" class="prism-code language-java codeBlock_bY9V thin-scrollbar"><code class="codeBlockLines_e6Vv"><span class="token-line" style="color:#bfc7d5"><span class="token annotation punctuation" style="color:rgb(199, 146, 234)">@Override</span><span class="token plain"></span><br></span><span class="token-line" style="color:#bfc7d5"><span class="token plain">  </span><span class="token keyword" style="font-style:italic">public</span><span class="token plain"> </span><span class="token class-name" style="color:rgb(255, 203, 107)">DataProcessorDescription</span><span class="token plain"> </span><span class="token function" style="color:rgb(130, 170, 255)">declareModel</span><span class="token punctuation" style="color:rgb(199, 146, 234)">(</span><span class="token punctuation" style="color:rgb(199, 146, 234)">)</span><span class="token plain"> </span><span class="token punctuation" style="color:rgb(199, 146, 234)">{</span><span class="token plain"></span><br></span><span class="token-line" style="color:#bfc7d5"><span class="token plain">    </span><span class="token keyword" style="font-style:italic">return</span><span class="token plain"> </span><span class="token class-name" style="color:rgb(255, 203, 107)">ProcessingElementBuilder</span><span class="token punctuation" style="color:rgb(199, 146, 234)">.</span><span class="token function" style="color:rgb(130, 170, 255)">create</span><span class="token punctuation" style="color:rgb(199, 146, 234)">(</span><span class="token string" style="color:rgb(195, 232, 141)">&quot;org.streampipes.examples.requirements&quot;</span><span class="token plain"> </span><span class="token operator" style="color:rgb(137, 221, 255)">+</span><span class="token plain"></span><br></span><span class="token-line" style="color:#bfc7d5"><span class="token plain">            </span><span class="token string" style="color:rgb(195, 232, 141)">&quot;.list&quot;</span><span class="token punctuation" style="color:rgb(199, 146, 234)">,</span><span class="token plain"> </span><span class="token string" style="color:rgb(195, 232, 141)">&quot;List requirements specification examples&quot;</span><span class="token punctuation" style="color:rgb(199, 146, 234)">,</span><span class="token plain"> </span><span class="token string" style="color:rgb(195, 232, 141)">&quot;&quot;</span><span class="token punctuation" style="color:rgb(199, 146, 234)">)</span><span class="token plain"></span><br></span><span class="token-line" style="color:#bfc7d5"><span class="token plain">            </span><span class="token punctuation" style="color:rgb(199, 146, 234)">.</span><span class="token function" style="color:rgb(130, 170, 255)">requiredStream</span><span class="token punctuation" style="color:rgb(199, 146, 234)">(</span><span class="token class-name" style="color:rgb(255, 203, 107)">StreamRequirementsBuilder</span><span class="token punctuation" style="color:rgb(199, 146, 234)">.</span><span class="token plain"></span><br></span><span class="token-line" style="color:#bfc7d5"><span class="token plain">                    </span><span class="token function" style="color:rgb(130, 170, 255)">create</span><span class="token punctuation" style="color:rgb(199, 146, 234)">(</span><span class="token punctuation" style="color:rgb(199, 146, 234)">)</span><span class="token plain"></span><br></span><span class="token-line" style="color:#bfc7d5"><span class="token plain">                    </span><span class="token punctuation" style="color:rgb(199, 146, 234)">.</span><span class="token function" style="color:rgb(130, 170, 255)">requiredProperty</span><span class="token punctuation" style="color:rgb(199, 146, 234)">(</span><span class="token class-name" style="color:rgb(255, 203, 107)">EpRequirements</span><span class="token punctuation" style="color:rgb(199, 146, 234)">.</span><span class="token function" style="color:rgb(130, 170, 255)">listRequirement</span><span class="token punctuation" style="color:rgb(199, 146, 234)">(</span><span class="token class-name" style="color:rgb(255, 203, 107)">Datatypes</span><span class="token class-name punctuation" style="color:rgb(199, 146, 234)">.</span><span class="token class-name" style="color:rgb(255, 203, 107)">Integer</span><span class="token punctuation" style="color:rgb(199, 146, 234)">)</span><span class="token punctuation" style="color:rgb(199, 146, 234)">)</span><span class="token plain"></span><br></span><span class="token-line" style="color:#bfc7d5"><span class="token plain">                    </span><span class="token punctuation" style="color:rgb(199, 146, 234)">.</span><span class="token function" style="color:rgb(130, 170, 255)">requiredProperty</span><span class="token punctuation" style="color:rgb(199, 146, 234)">(</span><span class="token class-name" style="color:rgb(255, 203, 107)">EpRequirements</span><span class="token punctuation" style="color:rgb(199, 146, 234)">.</span><span class="token function" style="color:rgb(130, 170, 255)">listRequirement</span><span class="token punctuation" style="color:rgb(199, 146, 234)">(</span><span class="token class-name" style="color:rgb(255, 203, 107)">Datatypes</span><span class="token class-name punctuation" style="color:rgb(199, 146, 234)">.</span><span class="token class-name" style="color:rgb(255, 203, 107)">Double</span><span class="token punctuation" style="color:rgb(199, 146, 234)">)</span><span class="token punctuation" style="color:rgb(199, 146, 234)">)</span><span class="token plain"></span><br></span><span class="token-line" style="color:#bfc7d5"><span class="token plain">                    </span><span class="token punctuation" style="color:rgb(199, 146, 234)">.</span><span class="token function" style="color:rgb(130, 170, 255)">requiredProperty</span><span class="token punctuation" style="color:rgb(199, 146, 234)">(</span><span class="token class-name" style="color:rgb(255, 203, 107)">EpRequirements</span><span class="token punctuation" style="color:rgb(199, 146, 234)">.</span><span class="token function" style="color:rgb(130, 170, 255)">listRequirement</span><span class="token punctuation" style="color:rgb(199, 146, 234)">(</span><span class="token class-name" style="color:rgb(255, 203, 107)">Datatypes</span><span class="token class-name punctuation" style="color:rgb(199, 146, 234)">.</span><span class="token class-name" style="color:rgb(255, 203, 107)">Boolean</span><span class="token punctuation" style="color:rgb(199, 146, 234)">)</span><span class="token punctuation" style="color:rgb(199, 146, 234)">)</span><span class="token plain"></span><br></span><span class="token-line" style="color:#bfc7d5"><span class="token plain">                    </span><span class="token punctuation" style="color:rgb(199, 146, 234)">.</span><span class="token function" style="color:rgb(130, 170, 255)">requiredProperty</span><span class="token punctuation" style="color:rgb(199, 146, 234)">(</span><span class="token class-name" style="color:rgb(255, 203, 107)">EpRequirements</span><span class="token punctuation" style="color:rgb(199, 146, 234)">.</span><span class="token function" style="color:rgb(130, 170, 255)">listRequirement</span><span class="token punctuation" style="color:rgb(199, 146, 234)">(</span><span class="token class-name" style="color:rgb(255, 203, 107)">Datatypes</span><span class="token class-name punctuation" style="color:rgb(199, 146, 234)">.</span><span class="token class-name" style="color:rgb(255, 203, 107)">String</span><span class="token punctuation" style="color:rgb(199, 146, 234)">)</span><span class="token punctuation" style="color:rgb(199, 146, 234)">)</span><span class="token plain"></span><br></span><span class="token-line" style="color:#bfc7d5"><span class="token plain">                    </span><span class="token punctuation" style="color:rgb(199, 146, 234)">.</span><span class="token function" style="color:rgb(130, 170, 255)">build</span><span class="token punctuation" style="color:rgb(199, 146, 234)">(</span><span class="token punctuation" style="color:rgb(199, 146, 234)">)</span><span class="token punctuation" style="color:rgb(199, 146, 234)">)</span><span class="token plain"></span><br></span><span class="token-line" style="color:#bfc7d5"><span class="token plain" style="display:inline-block"></span><br></span><span class="token-line" style="color:#bfc7d5"><span class="token plain" style="display:inline-block"></span><br></span><span class="token-line" style="color:#bfc7d5"><span class="token plain">            </span><span class="token punctuation" style="color:rgb(199, 146, 234)">.</span><span class="token function" style="color:rgb(130, 170, 255)">supportedProtocols</span><span class="token punctuation" style="color:rgb(199, 146, 234)">(</span><span class="token class-name" style="color:rgb(255, 203, 107)">SupportedProtocols</span><span class="token punctuation" style="color:rgb(199, 146, 234)">.</span><span class="token function" style="color:rgb(130, 170, 255)">kafka</span><span class="token punctuation" style="color:rgb(199, 146, 234)">(</span><span class="token punctuation" style="color:rgb(199, 146, 234)">)</span><span class="token punctuation" style="color:rgb(199, 146, 234)">)</span><span class="token plain"></span><br></span><span class="token-line" style="color:#bfc7d5"><span class="token plain">            </span><span class="token punctuation" style="color:rgb(199, 146, 234)">.</span><span class="token function" style="color:rgb(130, 170, 255)">supportedFormats</span><span class="token punctuation" style="color:rgb(199, 146, 234)">(</span><span class="token class-name" style="color:rgb(255, 203, 107)">SupportedFormats</span><span class="token punctuation" style="color:rgb(199, 146, 234)">.</span><span class="token function" style="color:rgb(130, 170, 255)">jsonFormat</span><span class="token punctuation" style="color:rgb(199, 146, 234)">(</span><span class="token punctuation" style="color:rgb(199, 146, 234)">)</span><span class="token punctuation" style="color:rgb(199, 146, 234)">)</span><span class="token plain"></span><br></span><span class="token-line" style="color:#bfc7d5"><span class="token plain">            </span><span class="token punctuation" style="color:rgb(199, 146, 234)">.</span><span class="token function" style="color:rgb(130, 170, 255)">outputStrategy</span><span class="token punctuation" style="color:rgb(199, 146, 234)">(</span><span class="token class-name" style="color:rgb(255, 203, 107)">OutputStrategies</span><span class="token punctuation" style="color:rgb(199, 146, 234)">.</span><span class="token function" style="color:rgb(130, 170, 255)">keep</span><span class="token punctuation" style="color:rgb(199, 146, 234)">(</span><span class="token punctuation" style="color:rgb(199, 146, 234)">)</span><span class="token punctuation" style="color:rgb(199, 146, 234)">)</span><span class="token plain"></span><br></span><span class="token-line" style="color:#bfc7d5"><span class="token plain" style="display:inline-block"></span><br></span><span class="token-line" style="color:#bfc7d5"><span class="token plain">            </span><span class="token punctuation" style="color:rgb(199, 146, 234)">.</span><span class="token function" style="color:rgb(130, 170, 255)">build</span><span class="token punctuation" style="color:rgb(199, 146, 234)">(</span><span class="token punctuation" style="color:rgb(199, 146, 234)">)</span><span class="token punctuation" style="color:rgb(199, 146, 234)">;</span><span class="token plain"></span><br></span><span class="token-line" style="color:#bfc7d5"><span class="token plain">  </span><span class="token punctuation" style="color:rgb(199, 146, 234)">}</span><br></span></code></pre><div class="buttonGroup__atx"><button type="button" aria-label="Copy code to clipboard" title="Copy" class="clean-btn"><span class="copyButtonIcons_eSgA" aria-hidden="true"><svg viewBox="0 0 24 24" class="copyButtonIcon_y97N"><path fill="currentColor" d="M19,21H8V7H19M19,5H8A2,2 0 0,0 6,7V21A2,2 0 0,0 8,23H19A2,2 0 0,0 21,21V7A2,2 0 0,0 19,5M16,1H4A2,2 0 0,0 2,3V17H4V3H16V1Z"></path></svg><svg viewBox="0 0 24 24" class="copyButtonSuccessIcon_LjdS"><path fill="currentColor" d="M21,7L9,19L3.5,13.5L4.91,12.09L9,16.17L19.59,5.59L21,7Z"></path></svg></span></button></div></div></div><h2 class="anchor anchorWithStickyNavbar_LWe7" id="requirements-on-nested-properties">Requirements on nested properties<a href="#requirements-on-nested-properties" class="hash-link" aria-label="Direct link to Requirements on nested properties" title="Direct link to Requirements on nested properties"></a></h2><p>(coming soon, see the Javadoc for now)</p></div><footer class="theme-doc-footer docusaurus-mt-lg"><div class="theme-doc-footer-edit-meta-row row"><div class="col"></div><div class="col lastUpdated_vwxv"><span class="theme-last-updated">Last updated<!-- --> on <b><time datetime="2023-07-12T16:12:17.000Z">Jul 12, 2023</time></b> by <b>Dominik Riemer</b></span></div></div></footer></article><nav class="pagination-nav docusaurus-mt-lg" aria-label="Docs pages"><a class="pagination-nav__link pagination-nav__link--prev" href="/docs/0.92.0/extend-sdk-event-model/"><div class="pagination-nav__sublabel">Previous</div><div class="pagination-nav__label">SDK: Event Model</div></a><a class="pagination-nav__link pagination-nav__link--next" href="/docs/0.92.0/extend-sdk-static-properties/"><div class="pagination-nav__sublabel">Next</div><div class="pagination-nav__label">SDK: Static Properties</div></a></nav></div></div><div class="col col--3"><div class="tableOfContents_bqdL thin-scrollbar theme-doc-toc-desktop"><ul class="table-of-contents table-of-contents__left-border"><li><a href="#introduction" class="table-of-contents__link toc-highlight">Introduction</a></li><li><a href="#the-streamrequirementsbuilder" class="table-of-contents__link toc-highlight">The StreamRequirementsBuilder</a></li><li><a href="#requirements-on-primitive-fields" class="table-of-contents__link toc-highlight">Requirements on primitive fields</a><ul><li><a href="#specifying-semantics" class="table-of-contents__link toc-highlight">Specifying semantics</a></li></ul></li><li><a href="#requirements-on-lists" class="table-of-contents__link toc-highlight">Requirements on lists</a></li><li><a href="#requirements-on-nested-properties" class="table-of-contents__link toc-highlight">Requirements on nested properties</a></li></ul></div></div></div></div></main></div></div><footer class="container_yWIM"><div class="linksRow_XFIr"><div class="linksCol_rFJL"><div>ASF</div><ul><li class="footer__item"><a href="https://www.apache.org/" target="_blank" rel="noopener noreferrer"><span></span><span>Foundation</span></a></li><li class="footer__item"><a href="https://www.apache.org/licenses/" target="_blank" rel="noopener noreferrer"><span></span><span>License</span></a></li><li class="footer__item"><a href="https://www.apache.org/events/" target="_blank" rel="noopener noreferrer"><span></span><span>Events</span></a></li><li class="footer__item"><a href="https://www.apache.org/security/" target="_blank" rel="noopener noreferrer"><span></span><span>Security</span></a></li><li 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