| /** |
| * Licensed to the Apache Software Foundation (ASF) under one or more contributor license agreements. See the NOTICE file distributed with |
| * this work for additional information regarding copyright ownership. The ASF licenses this file to you under the Apache License, Version |
| * 2.0 (the "License"); you may not use this file except in compliance with the License. You may obtain a copy of the License at |
| * |
| * http://www.apache.org/licenses/LICENSE-2.0 |
| * |
| * Unless required by applicable law or agreed to in writing, software distributed under the License is distributed on an "AS IS" BASIS, |
| * WITHOUT WARRANTIES OR CONDITIONS OF ANY KIND, either express or implied. See the License for the specific language governing permissions |
| * and limitations under the License. |
| */ |
| |
| package org.apache.storm.trident.operation; |
| |
| import java.util.List; |
| |
| |
| /** |
| * Interface for publishing tuples to a stream and reporting exceptions (to be displayed in Storm UI). |
| * |
| * Trident components that have the ability to emit tuples to a stream are passed an instance of this interface. |
| * |
| * For example, to emit a new tuple to a stream, you would do something like the following: |
| * |
| * ```java collector.emit(new Values("a", "b", "c")); ``` |
| * |
| * @see org.apache.storm.trident.Stream |
| * @see org.apache.storm.tuple.Values |
| */ |
| public interface TridentCollector { |
| /** |
| * Emits a tuple to a Stream |
| * |
| * @param values a list of values of which the tuple will be composed |
| */ |
| void emit(List<Object> values); |
| |
| /** |
| * Flush any buffered tuples (when batching is enabled) |
| */ |
| void flush(); |
| |
| /** |
| * Reports an error. The corresponding stack trace will be visible in the Storm UI. |
| * |
| * Note that calling this method does not alter the processing of a batch. To explicitly fail a batch and trigger a replay, components |
| * should throw {@link org.apache.storm.topology.FailedException}. |
| * |
| * @param t The instance of the error (Throwable) being reported. |
| */ |
| void reportError(Throwable t); |
| } |