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.spring;
018
019 import org.apache.camel.Endpoint;
020 import org.apache.camel.component.bean.BeanProcessor;
021 import org.apache.camel.component.event.EventComponent;
022 import org.apache.camel.component.event.EventEndpoint;
023 import org.apache.camel.impl.DefaultCamelContext;
024 import org.apache.camel.impl.ProcessorEndpoint;
025 import org.apache.camel.spi.Injector;
026 import org.apache.camel.spi.Registry;
027 import org.apache.camel.spring.spi.ApplicationContextRegistry;
028 import org.apache.camel.spring.spi.SpringInjector;
029 import org.apache.commons.logging.Log;
030 import org.apache.commons.logging.LogFactory;
031 import org.springframework.beans.BeansException;
032 import org.springframework.beans.factory.DisposableBean;
033 import org.springframework.beans.factory.InitializingBean;
034 import org.springframework.context.ApplicationContext;
035 import org.springframework.context.ApplicationContextAware;
036 import org.springframework.context.ApplicationEvent;
037 import org.springframework.context.ApplicationListener;
038 import org.springframework.context.ConfigurableApplicationContext;
039 import org.springframework.context.event.ContextRefreshedEvent;
040 import org.springframework.context.support.ClassPathXmlApplicationContext;
041
042 import static org.apache.camel.util.ObjectHelper.wrapRuntimeCamelException;
043
044 /**
045 * A Spring aware implementation of {@link org.apache.camel.CamelContext} which
046 * will automatically register itself with Springs lifecycle methods plus allows
047 * spring to be used to customize a any <a
048 * href="http://camel.apache.org/type-converter.html">Type Converters</a>
049 * as well as supporting accessing components and beans via the Spring
050 * {@link ApplicationContext}
051 *
052 * @version $Revision: 833859 $
053 */
054 public class SpringCamelContext extends DefaultCamelContext implements InitializingBean, DisposableBean,
055 ApplicationContextAware, ApplicationListener {
056
057 private static final transient Log LOG = LogFactory.getLog(SpringCamelContext.class);
058 private ApplicationContext applicationContext;
059 private EventEndpoint eventEndpoint;
060
061 public SpringCamelContext() {
062 }
063
064 public SpringCamelContext(ApplicationContext applicationContext) {
065 setApplicationContext(applicationContext);
066 }
067
068 public static SpringCamelContext springCamelContext(ApplicationContext applicationContext) throws Exception {
069 // lets try and look up a configured camel context in the context
070 String[] names = applicationContext.getBeanNamesForType(SpringCamelContext.class);
071 if (names.length == 1) {
072 return (SpringCamelContext)applicationContext.getBean(names[0], SpringCamelContext.class);
073 }
074 SpringCamelContext answer = new SpringCamelContext();
075 answer.setApplicationContext(applicationContext);
076 answer.afterPropertiesSet();
077 return answer;
078 }
079
080 public static SpringCamelContext springCamelContext(String configLocations) throws Exception {
081 return springCamelContext(new ClassPathXmlApplicationContext(configLocations));
082 }
083
084 public void afterPropertiesSet() throws Exception {
085 maybeStart();
086 }
087
088 public void destroy() throws Exception {
089 stop();
090 }
091
092 public void onApplicationEvent(ApplicationEvent event) {
093 if (LOG.isDebugEnabled()) {
094 LOG.debug("onApplicationEvent: " + event);
095 }
096
097 if (event instanceof ContextRefreshedEvent) {
098 // now lets start the CamelContext so that all its possible
099 // dependencies are initialized
100 try {
101 maybeStart();
102 } catch (Exception e) {
103 throw wrapRuntimeCamelException(e);
104 }
105 }
106
107 if (eventEndpoint != null) {
108 eventEndpoint.onApplicationEvent(event);
109 } else {
110 LOG.info("No spring-event endpoint enabled to handle event: " + event);
111 }
112 }
113
114 // Properties
115 // -----------------------------------------------------------------------
116
117 public ApplicationContext getApplicationContext() {
118 return applicationContext;
119 }
120
121 public void setApplicationContext(ApplicationContext applicationContext) throws BeansException {
122 this.applicationContext = applicationContext;
123 ClassLoader cl;
124
125 // set the application context classloader
126 if (applicationContext != null && applicationContext.getClassLoader() != null) {
127 cl = applicationContext.getClassLoader();
128 } else {
129 LOG.warn("Cannot find the class loader from application context, using the thread context class loader instead");
130 cl = Thread.currentThread().getContextClassLoader();
131 }
132 if (LOG.isDebugEnabled()) {
133 LOG.debug("Set the application context classloader to: " + cl);
134 }
135 this.setApplicationContextClassLoader(cl);
136
137 if (applicationContext instanceof ConfigurableApplicationContext) {
138 // only add if not already added
139 if (hasComponent("spring-event") == null) {
140 addComponent("spring-event", new EventComponent(applicationContext));
141 }
142 }
143 }
144
145 public EventEndpoint getEventEndpoint() {
146 return eventEndpoint;
147 }
148
149 public void setEventEndpoint(EventEndpoint eventEndpoint) {
150 this.eventEndpoint = eventEndpoint;
151 }
152
153 // Implementation methods
154 // -----------------------------------------------------------------------
155
156 @Override
157 protected void doStart() throws Exception {
158 super.doStart();
159 if (eventEndpoint == null) {
160 eventEndpoint = createEventEndpoint();
161 }
162 }
163
164 @Override
165 protected Injector createInjector() {
166 if (applicationContext instanceof ConfigurableApplicationContext) {
167 return new SpringInjector((ConfigurableApplicationContext)applicationContext);
168 } else {
169 LOG.warn("Cannot use SpringInjector as applicationContext is not a ConfigurableApplicationContext as its: "
170 + applicationContext);
171 return super.createInjector();
172 }
173 }
174
175 protected EventEndpoint createEventEndpoint() {
176 return getEndpoint("spring-event:default", EventEndpoint.class);
177 }
178
179 protected Endpoint convertBeanToEndpoint(String uri, Object bean) {
180 // We will use the type convert to build the endpoint first
181 Endpoint endpoint = getTypeConverter().convertTo(Endpoint.class, bean);
182 if (endpoint != null) {
183 endpoint.setCamelContext(this);
184 return endpoint;
185 }
186
187 return new ProcessorEndpoint(uri, this, new BeanProcessor(bean, this));
188 }
189
190 @Override
191 protected Registry createRegistry() {
192 return new ApplicationContextRegistry(getApplicationContext());
193 }
194
195 private void maybeStart() throws Exception {
196 if (!isStarted() && !isStarting()) {
197 start();
198 } else {
199 // ignore as Camel is already started
200 LOG.trace("Ignoring maybeStart() as Apache Camel is already started");
201 }
202 }
203
204 @Override
205 public String toString() {
206 StringBuilder sb = new StringBuilder();
207 sb.append("SpringCamelContext(").append(getName()).append(")");
208 if (applicationContext != null) {
209 sb.append(" with spring id ").append(applicationContext.getId());
210 }
211 return sb.toString();
212 }
213
214 }