001 /** 002 * Licensed to the Apache Software Foundation (ASF) under one or more 003 * contributor license agreements. See the NOTICE file distributed with 004 * this work for additional information regarding copyright ownership. 005 * The ASF licenses this file to You under the Apache License, Version 2.0 006 * (the "License"); you may not use this file except in compliance with 007 * the License. You may obtain a copy of the License at 008 * 009 * http://www.apache.org/licenses/LICENSE-2.0 010 * 011 * Unless required by applicable law or agreed to in writing, software 012 * distributed under the License is distributed on an "AS IS" BASIS, 013 * WITHOUT WARRANTIES OR CONDITIONS OF ANY KIND, either express or implied. 014 * See the License for the specific language governing permissions and 015 * limitations under the License. 016 */ 017 package org.apache.camel.processor; 018 019 020 021 import java.util.ArrayList; 022 import java.util.Iterator; 023 import java.util.List; 024 025 import org.apache.camel.Endpoint; 026 import org.apache.camel.Exchange; 027 import org.apache.camel.Expression; 028 import org.apache.camel.Processor; 029 import org.apache.camel.Producer; 030 import org.apache.camel.converter.ObjectConverter; 031 import org.apache.camel.impl.ProducerCache; 032 import org.apache.camel.impl.ServiceSupport; 033 import org.apache.camel.processor.aggregate.UseLatestAggregationStrategy; 034 import org.apache.camel.util.ExchangeHelper; 035 import static org.apache.camel.util.ObjectHelper.notNull; 036 037 /** 038 * Implements a dynamic <a 039 * href="http://activemq.apache.org/camel/recipient-list.html">Recipient List</a> 040 * pattern where the list of actual endpoints to send a message exchange to are 041 * dependent on some dynamic expression. 042 * 043 * @version $Revision: 41822 $ 044 */ 045 public class RecipientList extends ServiceSupport implements Processor { 046 private final Expression<Exchange> expression; 047 private ProducerCache<Exchange> producerCache = new ProducerCache<Exchange>(); 048 049 public RecipientList(Expression<Exchange> expression) { 050 notNull(expression, "expression"); 051 this.expression = expression; 052 } 053 054 @Override 055 public String toString() { 056 return "RecipientList[" + expression + "]"; 057 } 058 059 public void process(Exchange exchange) throws Exception { 060 Object receipientList = expression.evaluate(exchange); 061 Iterator iter = ObjectConverter.iterator(receipientList); 062 List<Processor> processors = new ArrayList<Processor>(); 063 while (iter.hasNext()) { 064 Object recipient = iter.next(); 065 Endpoint<Exchange> endpoint = resolveEndpoint(exchange, recipient); 066 Producer<Exchange> producer = producerCache.getProducer(endpoint); 067 processors.add(producer); 068 } 069 MulticastProcessor mp = new MulticastProcessor(processors, new UseLatestAggregationStrategy()); 070 mp.process(exchange); 071 } 072 073 protected Endpoint<Exchange> resolveEndpoint(Exchange exchange, Object recipient) { 074 return ExchangeHelper.resolveEndpoint(exchange, recipient); 075 } 076 077 protected void doStop() throws Exception { 078 producerCache.stop(); 079 } 080 081 protected void doStart() throws Exception { 082 } 083 }