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 import java.util.ArrayList; 020 import java.util.Iterator; 021 import java.util.List; 022 023 import org.apache.camel.Endpoint; 024 import org.apache.camel.Exchange; 025 import org.apache.camel.Expression; 026 import org.apache.camel.Processor; 027 import org.apache.camel.Producer; 028 import org.apache.camel.impl.ProducerCache; 029 import org.apache.camel.impl.ServiceSupport; 030 import org.apache.camel.processor.aggregate.UseLatestAggregationStrategy; 031 import org.apache.camel.util.ExchangeHelper; 032 import org.apache.camel.util.ObjectHelper; 033 import static org.apache.camel.util.ObjectHelper.notNull; 034 035 /** 036 * Implements a dynamic <a 037 * href="http://camel.apache.org/recipient-list.html">Recipient List</a> 038 * pattern where the list of actual endpoints to send a message exchange to are 039 * dependent on some dynamic expression. 040 * 041 * @version $Revision: 779038 $ 042 */ 043 public class RecipientList extends ServiceSupport implements Processor { 044 private ProducerCache producerCache; 045 private Expression expression; 046 047 public RecipientList() { 048 } 049 050 public RecipientList(Expression expression) { 051 notNull(expression, "expression"); 052 this.expression = expression; 053 } 054 055 @Override 056 public String toString() { 057 return "RecipientList[" + (expression != null ? expression : "") + "]"; 058 } 059 060 public void process(Exchange exchange) throws Exception { 061 Object receipientList = expression.evaluate(exchange, Object.class); 062 sendToRecipientList(exchange, receipientList); 063 } 064 065 /** 066 * Sends the given exchange to the recipient list 067 */ 068 public void sendToRecipientList(Exchange exchange, Object receipientList) throws Exception { 069 Iterator iter = ObjectHelper.createIterator(receipientList); 070 List<Processor> processors = new ArrayList<Processor>(); 071 while (iter.hasNext()) { 072 Object recipient = iter.next(); 073 Endpoint endpoint = resolveEndpoint(exchange, recipient); 074 Producer producer = getProducerCache(exchange).getProducer(endpoint); 075 processors.add(producer); 076 } 077 MulticastProcessor mp = new MulticastProcessor(processors, new UseLatestAggregationStrategy()); 078 mp.process(exchange); 079 } 080 081 protected ProducerCache getProducerCache(Exchange exchange) throws Exception { 082 // setup producer cache as we need to use the pluggable service pool defined on camel context 083 if (producerCache == null) { 084 this.producerCache = new ProducerCache(exchange.getContext().getProducerServicePool()); 085 this.producerCache.start(); 086 } 087 return this.producerCache; 088 } 089 090 protected Endpoint resolveEndpoint(Exchange exchange, Object recipient) { 091 // trim strings as end users might have added spaces between separators 092 if (recipient instanceof String) { 093 recipient = ((String)recipient).trim(); 094 } 095 return ExchangeHelper.resolveEndpoint(exchange, recipient); 096 } 097 098 protected void doStart() throws Exception { 099 if (producerCache != null) { 100 producerCache.start(); 101 } 102 } 103 104 protected void doStop() throws Exception { 105 if (producerCache != null) { 106 producerCache.stop(); 107 } 108 } 109 110 }