| /** |
| * 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.jms; |
| |
| import java.io.Serializable; |
| import javax.jms.JMSException; |
| import javax.jms.Message; |
| import org.apache.storm.topology.OutputFieldsDeclarer; |
| import org.apache.storm.tuple.Values; |
| |
| /** |
| * Interface to define classes that can produce a Storm <code>Values</code> objects |
| * from a <code>javax.jms.Message</code> object>. |
| * |
| * <p>Implementations are also responsible for declaring the output |
| * fields they produce. |
| * |
| * <p>If for some reason the implementation can't process a message |
| * (for example if it received a <code>javax.jms.ObjectMessage</code> |
| * when it was expecting a <code>javax.jms.TextMessage</code> it should |
| * return <code>null</code> to indicate to the <code>JmsSpout</code> that |
| * the message could not be processed. |
| * |
| */ |
| public interface JmsTupleProducer extends Serializable { |
| /** |
| * Process a JMS message object to create a Values object. |
| * |
| * @param msg - the JMS message |
| * @return the Values tuple, or null if the message couldn't be processed. |
| */ |
| Values toTuple(Message msg) throws JMSException; |
| |
| /** |
| * Declare the output fields produced by this JmsTupleProducer. |
| * |
| * @param declarer The OuputFieldsDeclarer for the spout. |
| */ |
| void declareOutputFields(OutputFieldsDeclarer declarer); |
| } |