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.NoTypeConversionAvailableException;
021 import org.apache.camel.component.bean.BeanProcessor;
022 import org.apache.camel.component.event.EventComponent;
023 import org.apache.camel.component.event.EventEndpoint;
024 import org.apache.camel.impl.DefaultCamelContext;
025 import org.apache.camel.impl.ProcessorEndpoint;
026 import org.apache.camel.spi.Injector;
027 import org.apache.camel.spi.Registry;
028 import org.apache.camel.spring.spi.ApplicationContextRegistry;
029 import org.apache.camel.spring.spi.SpringInjector;
030 import org.apache.camel.util.ObjectHelper;
031 import org.apache.commons.logging.Log;
032 import org.apache.commons.logging.LogFactory;
033 import org.springframework.beans.BeansException;
034 import org.springframework.beans.factory.DisposableBean;
035 import org.springframework.beans.factory.InitializingBean;
036 import org.springframework.context.ApplicationContext;
037 import org.springframework.context.ApplicationContextAware;
038 import org.springframework.context.ApplicationEvent;
039 import org.springframework.context.ApplicationListener;
040 import org.springframework.context.ConfigurableApplicationContext;
041 import org.springframework.context.event.ContextRefreshedEvent;
042 import org.springframework.context.event.ContextStoppedEvent;
043 import org.springframework.context.support.ClassPathXmlApplicationContext;
044
045 import static org.apache.camel.util.ObjectHelper.wrapRuntimeCamelException;
046
047 /**
048 * A Spring aware implementation of {@link org.apache.camel.CamelContext} which
049 * will automatically register itself with Springs lifecycle methods plus allows
050 * spring to be used to customize a any <a
051 * href="http://activemq.apache.org/camel/type-converter.html">Type Converters</a>
052 * as well as supporting accessing components and beans via the Spring
053 * {@link ApplicationContext}
054 *
055 * @version $Revision: 925954 $
056 */
057 public class SpringCamelContext extends DefaultCamelContext implements InitializingBean, DisposableBean,
058 ApplicationContextAware, ApplicationListener {
059
060 private static final transient Log LOG = LogFactory.getLog(SpringCamelContext.class);
061 private ApplicationContext applicationContext;
062 private EventEndpoint eventEndpoint;
063 private boolean shouldStartContext =
064 ObjectHelper.getSystemProperty("shouldStartContext", Boolean.TRUE); // start context by default
065
066 public SpringCamelContext() {
067 }
068
069 public SpringCamelContext(ApplicationContext applicationContext) {
070 setApplicationContext(applicationContext);
071 }
072
073 public static SpringCamelContext springCamelContext(ApplicationContext applicationContext) throws Exception {
074 // lets try and look up a configured camel context in the context
075 String[] names = applicationContext.getBeanNamesForType(SpringCamelContext.class);
076 if (names.length == 1) {
077 return (SpringCamelContext)applicationContext.getBean(names[0], SpringCamelContext.class);
078 }
079 SpringCamelContext answer = new SpringCamelContext();
080 answer.setApplicationContext(applicationContext);
081 answer.afterPropertiesSet();
082 return answer;
083 }
084
085 public static SpringCamelContext springCamelContext(String configLocations) throws Exception {
086 return springCamelContext(new ClassPathXmlApplicationContext(configLocations));
087 }
088
089 public void afterPropertiesSet() throws Exception {
090 maybeStart();
091 }
092
093 private void maybeStart() throws Exception {
094 if (!getShouldStartContext()) {
095 LOG.info("Not starting Apache Camel as property ShouldStartContext is false");
096 return;
097 }
098
099 if (!isStarted() && !isStarting()) {
100 // Make sure we will not get into the endless loop of calling star
101 LOG.info("Starting Apache Camel as property ShouldStartContext is true");
102 start();
103 } else {
104 // ignore as Camel is already started
105 LOG.trace("Ignoring maybeStart() as Apache Camel is already started");
106 }
107 }
108
109 public void destroy() throws Exception {
110 stop();
111 }
112
113 public void onApplicationEvent(ApplicationEvent event) {
114 if (LOG.isDebugEnabled()) {
115 LOG.debug("onApplicationEvent: " + event);
116 }
117
118 if (event instanceof ContextRefreshedEvent) {
119 // now lets start the CamelContext so that all its possible
120 // dependencies are initialized
121 try {
122 maybeStart();
123 } catch (RuntimeException e) {
124 throw e;
125 } catch (Exception e) {
126 throw wrapRuntimeCamelException(e);
127 }
128 } else if (event instanceof ContextStoppedEvent) {
129 try {
130 maybeStop();
131 } catch (Exception e) {
132 throw wrapRuntimeCamelException(e);
133 }
134 }
135
136 if (eventEndpoint != null) {
137 eventEndpoint.onApplicationEvent(event);
138 } else {
139 LOG.warn("No spring-event endpoint enabled to handle event: " + event);
140 }
141 }
142
143 // Properties
144 // -----------------------------------------------------------------------
145
146 public ApplicationContext getApplicationContext() {
147 return applicationContext;
148 }
149
150 public void setApplicationContext(ApplicationContext applicationContext) throws BeansException {
151 this.applicationContext = applicationContext;
152
153 if (applicationContext instanceof ConfigurableApplicationContext) {
154 addComponent("spring-event", new EventComponent(applicationContext));
155 }
156 }
157
158 public EventEndpoint getEventEndpoint() {
159 return eventEndpoint;
160 }
161
162 public void setEventEndpoint(EventEndpoint eventEndpoint) {
163 this.eventEndpoint = eventEndpoint;
164 }
165
166 // Implementation methods
167 // -----------------------------------------------------------------------
168
169 @Override
170 protected void doStart() throws Exception {
171 maybeDoStart();
172 }
173
174 protected void maybeDoStart() throws Exception {
175 if (getShouldStartContext()) {
176 super.doStart();
177 if (eventEndpoint == null) {
178 eventEndpoint = createEventEndpoint();
179 }
180 }
181 }
182
183 @Override
184 protected Injector createInjector() {
185 if (applicationContext instanceof ConfigurableApplicationContext) {
186 return new SpringInjector((ConfigurableApplicationContext)applicationContext);
187 } else {
188 LOG.warn("Cannot use SpringInjector as applicationContext is not a ConfigurableApplicationContext as its: "
189 + applicationContext);
190 return super.createInjector();
191 }
192 }
193
194 protected EventEndpoint createEventEndpoint() {
195 return getEndpoint("spring-event:default", EventEndpoint.class);
196 }
197
198 protected Endpoint convertBeanToEndpoint(String uri, Object bean) {
199 // We will use the type convert to build the endpoint first
200 try {
201 Endpoint endpoint = getTypeConverter().convertTo(Endpoint.class, bean);
202 if (endpoint != null) {
203 endpoint.setCamelContext(this);
204 return endpoint;
205 }
206 } catch (NoTypeConversionAvailableException ex) {
207 // ignore, handled below
208 }
209
210 return new ProcessorEndpoint(uri, this, new BeanProcessor(bean, this));
211 }
212
213 @Override
214 protected Registry createRegistry() {
215 return new ApplicationContextRegistry(getApplicationContext());
216 }
217
218 public void setShouldStartContext(boolean shouldStartContext) {
219 this.shouldStartContext = shouldStartContext;
220 }
221
222 public boolean getShouldStartContext() {
223 return shouldStartContext;
224 }
225
226 private void maybeStop() throws Exception {
227 if (!isStopping() && !isStopped()) {
228 stop();
229 } else {
230 // ignore as Camel is already stopped
231 LOG.trace("Ignoring maybeStop() as Apache Camel is already stopped");
232 }
233 }
234
235 @Override
236 public String toString() {
237 StringBuilder sb = new StringBuilder();
238 sb.append("SpringCamelContext(").append(getName()).append(")");
239 return sb.toString();
240 }
241
242 }