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.PollingConsumer; 029 import org.apache.camel.Processor; 030 import org.apache.camel.Producer; 031 import org.apache.camel.ProducerTemplate; 032 import org.apache.camel.Service; 033 import org.apache.camel.component.bean.BeanProcessor; 034 import org.apache.camel.component.bean.ProxyHelper; 035 import org.apache.camel.util.CamelContextHelper; 036 import org.apache.camel.util.ObjectHelper; 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://camel.apache.org/spring.html">Spring</a> 043 * and <a href="http://camel.apache.org/guice.html">Guice</a> support. 044 * 045 * @version $Revision: 776194 $ 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 Consume consume = method.getAnnotation(Consume.class); 070 if (consume != null) { 071 LOG.info("Creating a consumer for: " + consume); 072 subscribeMethod(method, bean, consume.uri(), consume.ref()); 073 } 074 } 075 076 public void subscribeMethod(Method method, Object bean, String endpointUri, String endpointName) { 077 // lets bind this method to a listener 078 String injectionPointName = method.getName(); 079 Endpoint endpoint = getEndpointInjection(endpointUri, endpointName, injectionPointName, true); 080 if (endpoint != null) { 081 try { 082 Processor processor = createConsumerProcessor(bean, method, endpoint); 083 Consumer consumer = endpoint.createConsumer(processor); 084 if (LOG.isDebugEnabled()) { 085 LOG.debug("Created processor: " + processor + " for consumer: " + consumer); 086 } 087 startService(consumer); 088 } catch (Exception e) { 089 throw ObjectHelper.wrapRuntimeCamelException(e); 090 } 091 } 092 } 093 094 public void startService(Service service) throws Exception { 095 CamelContext camelContext = getCamelContext(); 096 if (camelContext instanceof DefaultCamelContext) { 097 DefaultCamelContext defaultCamelContext = (DefaultCamelContext) camelContext; 098 defaultCamelContext.addService(service); 099 } else { 100 service.start(); 101 } 102 } 103 104 /** 105 * Create a processor which invokes the given method when an incoming 106 * message exchange is received 107 */ 108 protected Processor createConsumerProcessor(final Object pojo, final Method method, final Endpoint endpoint) { 109 BeanProcessor answer = new BeanProcessor(pojo, getCamelContext()); 110 answer.setMethodObject(method); 111 return answer; 112 } 113 114 protected Endpoint getEndpointInjection(String uri, String name, String injectionPointName, boolean mandatory) { 115 return CamelContextHelper.getEndpointInjection(getCamelContext(), uri, name, injectionPointName, mandatory); 116 } 117 118 /** 119 * Creates the object to be injected for an {@link org.apache.camel.EndpointInject} or {@link org.apache.camel.Produce} injection point 120 */ 121 public Object getInjectionValue(Class<?> type, String endpointUri, String endpointRef, String injectionPointName) { 122 if (type.isAssignableFrom(ProducerTemplate.class)) { 123 return createInjectionProducerTemplate(endpointUri, endpointRef, injectionPointName); 124 } else { 125 Endpoint endpoint = getEndpointInjection(endpointUri, endpointRef, injectionPointName, true); 126 if (endpoint != null) { 127 if (type.isInstance(endpoint)) { 128 return endpoint; 129 } else if (type.isAssignableFrom(Producer.class)) { 130 return createInjectionProducer(endpoint); 131 } else if (type.isAssignableFrom(PollingConsumer.class)) { 132 return createInjectionPollingConsumer(endpoint); 133 } else if (type.isInterface()) { 134 // lets create a proxy 135 try { 136 return ProxyHelper.createProxy(endpoint, type); 137 } catch (Exception e) { 138 throw createProxyInstantiationRuntimeException(type, endpoint, e); 139 } 140 } else { 141 throw new IllegalArgumentException("Invalid type: " + type.getName() 142 + " which cannot be injected via @EndpointInject/@Produce for: " + endpoint); 143 } 144 } 145 return null; 146 } 147 } 148 149 /** 150 * Factory method to create a {@link org.apache.camel.ProducerTemplate} to be injected into a POJO 151 */ 152 protected ProducerTemplate createInjectionProducerTemplate(String endpointUri, String endpointRef, String injectionPointName) { 153 // endpoint is optional for this injection point 154 Endpoint endpoint = getEndpointInjection(endpointUri, endpointRef, injectionPointName, false); 155 return new DefaultProducerTemplate(getCamelContext(), endpoint); 156 } 157 158 /** 159 * Factory method to create a started {@link org.apache.camel.PollingConsumer} to be injected into a POJO 160 */ 161 protected PollingConsumer createInjectionPollingConsumer(Endpoint endpoint) { 162 try { 163 PollingConsumer pollingConsumer = endpoint.createPollingConsumer(); 164 startService(pollingConsumer); 165 return pollingConsumer; 166 } catch (Exception e) { 167 throw ObjectHelper.wrapRuntimeCamelException(e); 168 } 169 } 170 171 /** 172 * A Factory method to create a started {@link org.apache.camel.Producer} to be injected into a POJO 173 */ 174 protected Producer createInjectionProducer(Endpoint endpoint) { 175 try { 176 Producer producer = endpoint.createProducer(); 177 startService(producer); 178 return producer; 179 } catch (Exception e) { 180 throw ObjectHelper.wrapRuntimeCamelException(e); 181 } 182 } 183 184 protected RuntimeException createProxyInstantiationRuntimeException(Class<?> type, Endpoint endpoint, Exception e) { 185 return new ProxyInstantiationException(type, endpoint, e); 186 } 187 }