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.impl.DefaultEndpoint; 023 import org.apache.camel.impl.DefaultProducer; 024 import org.apache.camel.processor.loadbalancer.LoadBalancer; 025 import org.apache.camel.processor.loadbalancer.TopicLoadBalancer; 026 import org.apache.camel.util.ObjectHelper; 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 import static org.apache.camel.util.ObjectHelper.wrapRuntimeCamelException; 033 034 035 /** 036 * An <a href="http://camel.apache.org/event.html">Event Endpoint</a> 037 * for working with Spring ApplicationEvents 038 * 039 * @version 040 */ 041 public class EventEndpoint extends DefaultEndpoint implements ApplicationContextAware { 042 private LoadBalancer loadBalancer; 043 private ApplicationContext applicationContext; 044 045 public EventEndpoint(String endpointUri, EventComponent component) { 046 super(endpointUri, component); 047 this.applicationContext = component.getApplicationContext(); 048 } 049 050 /** 051 * <b>Note:</b> It is preferred to create endpoints using the associated 052 * component. 053 * @param endpointUri 054 */ 055 @Deprecated 056 public EventEndpoint(String endpointUri) { 057 super(endpointUri); 058 } 059 060 public void setApplicationContext(ApplicationContext applicationContext) throws BeansException { 061 this.applicationContext = applicationContext; 062 } 063 064 public ApplicationContext getApplicationContext() { 065 return applicationContext; 066 } 067 068 public boolean isSingleton() { 069 return true; 070 } 071 072 public Producer createProducer() throws Exception { 073 ObjectHelper.notNull(applicationContext, "applicationContext"); 074 return new DefaultProducer(this) { 075 public void process(Exchange exchange) throws Exception { 076 ApplicationEvent event = toApplicationEvent(exchange); 077 applicationContext.publishEvent(event); 078 } 079 }; 080 } 081 082 public EventConsumer createConsumer(Processor processor) throws Exception { 083 ObjectHelper.notNull(applicationContext, "applicationContext"); 084 return new EventConsumer(this, processor); 085 } 086 087 public void onApplicationEvent(ApplicationEvent event) { 088 Exchange exchange = createExchange(); 089 exchange.getIn().setBody(event); 090 try { 091 getLoadBalancer().process(exchange); 092 } catch (Exception e) { 093 throw wrapRuntimeCamelException(e); 094 } 095 } 096 097 public LoadBalancer getLoadBalancer() { 098 if (loadBalancer == null) { 099 loadBalancer = createLoadBalancer(); 100 } 101 return loadBalancer; 102 } 103 104 public void setLoadBalancer(LoadBalancer loadBalancer) { 105 this.loadBalancer = loadBalancer; 106 } 107 108 // Implementation methods 109 // ------------------------------------------------------------------------- 110 public synchronized void consumerStarted(EventConsumer consumer) { 111 getLoadBalancer().addProcessor(consumer.getProcessor()); 112 } 113 114 public synchronized void consumerStopped(EventConsumer consumer) { 115 getLoadBalancer().removeProcessor(consumer.getProcessor()); 116 } 117 118 protected LoadBalancer createLoadBalancer() { 119 return new TopicLoadBalancer(); 120 } 121 122 protected ApplicationEvent toApplicationEvent(Exchange exchange) { 123 ApplicationEvent event = exchange.getIn().getBody(ApplicationEvent.class); 124 if (event != null) { 125 return event; 126 } 127 return new CamelEvent(this, exchange); 128 } 129 }