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.component.event; 018 019 import org.apache.camel.Exchange; 020 import org.apache.camel.Processor; 021 import org.apache.camel.Producer; 022 import org.apache.camel.RuntimeCamelException; 023 import org.apache.camel.impl.DefaultEndpoint; 024 import org.apache.camel.impl.DefaultProducer; 025 import org.apache.camel.processor.loadbalancer.LoadBalancer; 026 import org.apache.camel.processor.loadbalancer.TopicLoadBalancer; 027 import org.springframework.beans.BeansException; 028 import org.springframework.context.ApplicationContext; 029 import org.springframework.context.ApplicationContextAware; 030 import org.springframework.context.ApplicationEvent; 031 032 /** 033 * An <a href="http://activemq.apache.org/camel/event.html">Event Endpoint</a> 034 * for working with Spring ApplicationEvents 035 * 036 * @version $Revision: 41334 $ 037 */ 038 public class EventEndpoint extends DefaultEndpoint<Exchange> implements ApplicationContextAware { 039 private LoadBalancer loadBalancer; 040 private ApplicationContext applicationContext; 041 042 public EventEndpoint(String endpointUri, EventComponent component) { 043 super(endpointUri, component); 044 this.applicationContext = component.getApplicationContext(); 045 } 046 047 public EventEndpoint(String endpointUri) { 048 super(endpointUri); 049 } 050 051 public void setApplicationContext(ApplicationContext applicationContext) throws BeansException { 052 this.applicationContext = applicationContext; 053 } 054 055 public ApplicationContext getApplicationContext() { 056 return applicationContext; 057 } 058 059 public boolean isSingleton() { 060 return true; 061 } 062 063 public Producer<Exchange> createProducer() throws Exception { 064 return new DefaultProducer<Exchange>(this) { 065 public void process(Exchange exchange) throws Exception { 066 ApplicationEvent event = toApplicationEvent(exchange); 067 getApplicationContext().publishEvent(event); 068 } 069 }; 070 } 071 072 public EventConsumer createConsumer(Processor processor) throws Exception { 073 return new EventConsumer(this, processor); 074 } 075 076 public void onApplicationEvent(ApplicationEvent event) { 077 Exchange exchange = createExchange(); 078 exchange.getIn().setBody(event); 079 try { 080 getLoadBalancer().process(exchange); 081 } catch (Exception e) { 082 throw new RuntimeCamelException(e); 083 } 084 } 085 086 public LoadBalancer getLoadBalancer() { 087 if (loadBalancer == null) { 088 loadBalancer = createLoadBalancer(); 089 } 090 return loadBalancer; 091 } 092 093 public void setLoadBalancer(LoadBalancer loadBalancer) { 094 this.loadBalancer = loadBalancer; 095 } 096 097 // Implementation methods 098 // ------------------------------------------------------------------------- 099 public synchronized void consumerStarted(EventConsumer consumer) { 100 getLoadBalancer().addProcessor(consumer.getProcessor()); 101 } 102 103 public synchronized void consumerStopped(EventConsumer consumer) { 104 getLoadBalancer().removeProcessor(consumer.getProcessor()); 105 } 106 107 protected LoadBalancer createLoadBalancer() { 108 return new TopicLoadBalancer(); 109 } 110 111 protected ApplicationEvent toApplicationEvent(Exchange exchange) { 112 ApplicationEvent event = exchange.getIn().getBody(ApplicationEvent.class); 113 if (event == null) { 114 event = new CamelEvent(this, exchange); 115 } 116 return event; 117 } 118 119 }