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.loadbalancer;
018
019 import java.util.List;
020
021 import org.apache.camel.AsyncCallback;
022 import org.apache.camel.Exchange;
023 import org.apache.camel.Processor;
024
025 /**
026 * A {@link LoadBalancer} implementations which sends to all destinations
027 * (rather like JMS Topics).
028 *
029 * @version $Revision: 736571 $
030 *
031 */
032 public class TopicLoadBalancer extends LoadBalancerSupport {
033
034 public void process(Exchange exchange) throws Exception {
035 List<Processor> list = getProcessors();
036 for (Processor processor : list) {
037 Exchange copy = copyExchangeStrategy(processor, exchange);
038 processor.process(copy);
039 }
040 }
041
042 /**
043 * Strategy method to copy the exchange before sending to another endpoint.
044 * Derived classes such as the {@link org.apache.camel.processor.Pipeline Pipeline}
045 * will not clone the exchange
046 *
047 * @param processor the processor that will send the exchange
048 * @param exchange the exchange
049 * @return the current exchange if no copying is required such as for a
050 * pipeline otherwise a new copy of the exchange is returned.
051 */
052 protected Exchange copyExchangeStrategy(Processor processor, Exchange exchange) {
053 return exchange.copy();
054 }
055
056 public boolean process(Exchange exchange, AsyncCallback callback) {
057 List<Processor> list = getProcessors();
058 for (Processor processor : list) {
059 Exchange copy = copyExchangeStrategy(processor, exchange);
060 try {
061 processor.process(copy);
062 } catch (Exception ex) {
063 // We don't handle the exception here
064 }
065 }
066 callback.done(false);
067 return false;
068 }
069 }