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.impl; 018 019 import java.lang.reflect.Method; 020 021 import javax.xml.bind.annotation.XmlTransient; 022 023 import org.apache.camel.CamelContext; 024 import org.apache.camel.CamelContextAware; 025 import org.apache.camel.Consume; 026 import org.apache.camel.Consumer; 027 import org.apache.camel.Endpoint; 028 import org.apache.camel.MessageDriven; 029 import org.apache.camel.PollingConsumer; 030 import org.apache.camel.Processor; 031 import org.apache.camel.Producer; 032 import org.apache.camel.ProducerTemplate; 033 import org.apache.camel.Service; 034 import org.apache.camel.component.bean.BeanProcessor; 035 import org.apache.camel.component.bean.ProxyHelper; 036 import org.apache.camel.util.CamelContextHelper; 037 import org.apache.commons.logging.Log; 038 import org.apache.commons.logging.LogFactory; 039 040 /** 041 * A helper class for Camel based injector or post processing hooks which can be reused by 042 * both the <a href="http://activemq.apache.org/camel/spring.html">Spring</a> 043 * and <a href="http://activemq.apache.org/camel/guice.html">Guice</a> support. 044 * 045 * @version $Revision: 63996 $ 046 */ 047 public class CamelPostProcessorHelper implements CamelContextAware { 048 private static final transient Log LOG = LogFactory.getLog(CamelPostProcessorHelper.class); 049 050 @XmlTransient 051 private CamelContext camelContext; 052 053 public CamelPostProcessorHelper() { 054 } 055 056 public CamelPostProcessorHelper(CamelContext camelContext) { 057 this.setCamelContext(camelContext); 058 } 059 060 public CamelContext getCamelContext() { 061 return camelContext; 062 } 063 064 public void setCamelContext(CamelContext camelContext) { 065 this.camelContext = camelContext; 066 } 067 068 public void consumerInjection(Method method, Object bean) { 069 MessageDriven annotation = method.getAnnotation(MessageDriven.class); 070 if (annotation != null) { 071 LOG.info("Creating a consumer for: " + annotation); 072 subscribeMethod(method, bean, annotation.uri(), annotation.name()); 073 } 074 075 Consume consume = method.getAnnotation(Consume.class); 076 if (consume != null) { 077 LOG.info("Creating a consumer for: " + consume); 078 subscribeMethod(method, bean, consume.uri(), consume.ref()); 079 } 080 } 081 082 protected void subscribeMethod(Method method, Object bean, String endpointUri, String endpointName) { 083 // lets bind this method to a listener 084 String injectionPointName = method.getName(); 085 Endpoint endpoint = getEndpointInjection(endpointUri, endpointName, injectionPointName, true); 086 if (endpoint != null) { 087 try { 088 Processor processor = createConsumerProcessor(bean, method, endpoint); 089 LOG.info("Created processor: " + processor); 090 Consumer consumer = endpoint.createConsumer(processor); 091 startService(consumer); 092 } catch (Exception e) { 093 LOG.warn(e); 094 throw org.apache.camel.util.ObjectHelper.wrapRuntimeCamelException(e); 095 } 096 } 097 } 098 099 public void startService(Service service) throws Exception { 100 CamelContext camelContext = getCamelContext(); 101 if (camelContext instanceof DefaultCamelContext) { 102 DefaultCamelContext defaultCamelContext = (DefaultCamelContext) camelContext; 103 defaultCamelContext.addService(service); 104 } else { 105 service.start(); 106 } 107 } 108 109 /** 110 * Create a processor which invokes the given method when an incoming 111 * message exchange is received 112 */ 113 protected Processor createConsumerProcessor(final Object pojo, final Method method, final Endpoint endpoint) { 114 BeanProcessor answer = new BeanProcessor(pojo, getCamelContext()); 115 answer.setMethodObject(method); 116 return answer; 117 } 118 119 protected Endpoint getEndpointInjection(String uri, String name, String injectionPointName, boolean mandatory) { 120 return CamelContextHelper.getEndpointInjection(getCamelContext(), uri, name, injectionPointName, mandatory); 121 } 122 123 /** 124 * Creates the object to be injected for an {@link org.apache.camel.EndpointInject} or {@link org.apache.camel.Produce} injection point 125 */ 126 public Object getInjectionValue(Class<?> type, String endpointUri, String endpointRef, String injectionPointName) { 127 if (type.isAssignableFrom(ProducerTemplate.class)) { 128 // endpoint is optional for this injection point 129 Endpoint endpoint = getEndpointInjection(endpointUri, endpointRef, injectionPointName, false); 130 return new DefaultProducerTemplate(getCamelContext(), endpoint); 131 } else { 132 Endpoint endpoint = getEndpointInjection(endpointUri, endpointRef, injectionPointName, true); 133 if (endpoint != null) { 134 if (type.isInstance(endpoint)) { 135 return endpoint; 136 } else if (type.isAssignableFrom(Producer.class)) { 137 return createInjectionProducer(endpoint); 138 } else if (type.isAssignableFrom(PollingConsumer.class)) { 139 return createInjectionPollingConsumer(endpoint); 140 } else if (type.isInterface()) { 141 // lets create a proxy 142 try { 143 return ProxyHelper.createProxy(endpoint, type); 144 } catch (Exception e) { 145 throw createProxyInstantiationRuntimeException(type, endpoint, e); 146 } 147 } else { 148 throw new IllegalArgumentException("Invalid type: " + type.getName() + " which cannot be injected via @EndpointInject for " + endpoint); 149 } 150 } 151 return null; 152 } 153 } 154 155 protected RuntimeException createProxyInstantiationRuntimeException(Class<?> type, Endpoint endpoint, Exception e) { 156 return new ProxyInstantiationException(type, endpoint, e); 157 } 158 159 /** 160 * Factory method to create a started {@link org.apache.camel.PollingConsumer} to be injected 161 * into a POJO 162 */ 163 protected PollingConsumer createInjectionPollingConsumer(Endpoint endpoint) { 164 try { 165 PollingConsumer pollingConsumer = endpoint.createPollingConsumer(); 166 startService(pollingConsumer); 167 return pollingConsumer; 168 } catch (Exception e) { 169 throw org.apache.camel.util.ObjectHelper.wrapRuntimeCamelException(e); 170 } 171 } 172 173 /** 174 * A Factory method to create a started {@link org.apache.camel.Producer} to be injected into 175 * a POJO 176 */ 177 protected Producer createInjectionProducer(Endpoint endpoint) { 178 try { 179 Producer producer = endpoint.createProducer(); 180 startService(producer); 181 return producer; 182 } catch (Exception e) { 183 throw org.apache.camel.util.ObjectHelper.wrapRuntimeCamelException(e); 184 } 185 } 186 }