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 org.apache.camel.Endpoint; 020 import org.apache.camel.Exchange; 021 import org.apache.camel.ExchangePattern; 022 import org.apache.camel.Message; 023 import org.apache.camel.Processor; 024 import org.apache.camel.Producer; 025 import org.apache.camel.ProducerCallback; 026 import org.apache.camel.impl.ProducerCache; 027 import org.apache.camel.impl.ServiceSupport; 028 import org.apache.camel.model.RoutingSlipDefinition; 029 import org.apache.camel.util.ExchangeHelper; 030 031 import static org.apache.camel.util.ObjectHelper.notNull; 032 033 /** 034 * Implements a <a href="http://camel.apache.org/routing-slip.html">Routing Slip</a> 035 * pattern where the list of actual endpoints to send a message exchange to are 036 * dependent on the value of a message header. 037 */ 038 public class RoutingSlip extends ServiceSupport implements Processor, Traceable { 039 private ProducerCache producerCache; 040 private final String header; 041 private final String uriDelimiter; 042 043 public RoutingSlip(String header) { 044 this(header, RoutingSlipDefinition.DEFAULT_DELIMITER); 045 } 046 047 public RoutingSlip(String header, String uriDelimiter) { 048 notNull(header, "header"); 049 notNull(uriDelimiter, "uriDelimiter"); 050 051 this.header = header; 052 this.uriDelimiter = uriDelimiter; 053 } 054 055 @Override 056 public String toString() { 057 return "RoutingSlip[header=" + header + " uriDelimiter=" + uriDelimiter + "]"; 058 } 059 060 public String getTraceLabel() { 061 return "RoutingSlip[" + header + "]"; 062 } 063 064 public void process(Exchange exchange) throws Exception { 065 Message message = exchange.getIn(); 066 String[] recipients = recipients(message); 067 Exchange current = exchange; 068 069 for (String nextRecipient : recipients) { 070 Endpoint endpoint = resolveEndpoint(exchange, nextRecipient); 071 072 Exchange copy = current.newInstance(); 073 updateRoutingSlip(current); 074 copyOutToIn(copy, current); 075 076 getProducerCache(exchange).doInProducer(endpoint, copy, null, new ProducerCallback<Object>() { 077 public Object doInProducer(Producer producer, Exchange exchange, ExchangePattern exchangePattern) throws Exception { 078 producer.process(exchange); 079 return exchange; 080 } 081 }); 082 083 current = copy; 084 } 085 ExchangeHelper.copyResults(exchange, current); 086 } 087 088 protected ProducerCache getProducerCache(Exchange exchange) throws Exception { 089 // setup producer cache as we need to use the pluggable service pool defined on camel context 090 if (producerCache == null) { 091 this.producerCache = new ProducerCache(exchange.getContext().getProducerServicePool()); 092 this.producerCache.start(); 093 } 094 return this.producerCache; 095 } 096 097 protected Endpoint resolveEndpoint(Exchange exchange, Object recipient) { 098 return ExchangeHelper.resolveEndpoint(exchange, recipient); 099 } 100 101 protected void doStart() throws Exception { 102 if (producerCache != null) { 103 producerCache.start(); 104 } 105 } 106 107 protected void doStop() throws Exception { 108 if (producerCache != null) { 109 producerCache.stop(); 110 } 111 } 112 113 private void updateRoutingSlip(Exchange current) { 114 Message message = getResultMessage(current); 115 String oldSlip = message.getHeader(header, String.class); 116 if (oldSlip != null) { 117 int delimiterIndex = oldSlip.indexOf(uriDelimiter); 118 String newSlip = delimiterIndex > 0 ? oldSlip.substring(delimiterIndex + 1) : ""; 119 message.setHeader(header, newSlip); 120 } 121 } 122 123 /** 124 * Returns the outbound message if available. Otherwise return the inbound 125 * message. 126 */ 127 private Message getResultMessage(Exchange exchange) { 128 if (exchange.hasOut()) { 129 return exchange.getOut(); 130 } else { 131 // if this endpoint had no out (like a mock endpoint) just take the in 132 return exchange.getIn(); 133 } 134 } 135 136 /** 137 * Return the list of recipients defined in the routing slip in the 138 * specified message. 139 */ 140 private String[] recipients(Message message) { 141 Object headerValue = message.getHeader(header); 142 if (headerValue != null && !headerValue.equals("")) { 143 return headerValue.toString().split(uriDelimiter); 144 } 145 return new String[] {}; 146 } 147 148 /** 149 * Copy the outbound data in 'source' to the inbound data in 'result'. 150 */ 151 private void copyOutToIn(Exchange result, Exchange source) { 152 result.setException(source.getException()); 153 154 if (source.hasFault()) { 155 result.getFault().copyFrom(source.getFault()); 156 } 157 158 result.setIn(getResultMessage(source)); 159 160 result.getProperties().clear(); 161 result.getProperties().putAll(source.getProperties()); 162 } 163 }