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: 724293 $
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 }