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.support.ClassPathXmlApplicationContext;
043
044 import static org.apache.camel.util.ObjectHelper.wrapRuntimeCamelException;
045
046 /**
047 * A Spring aware implementation of {@link org.apache.camel.CamelContext} which
048 * will automatically register itself with Springs lifecycle methods plus allows
049 * spring to be used to customize a any <a
050 * href="http://activemq.apache.org/camel/type-converter.html">Type Converters</a>
051 * as well as supporting accessing components and beans via the Spring
052 * {@link ApplicationContext}
053 *
054 * @version $Revision: 787932 $
055 */
056 public class SpringCamelContext extends DefaultCamelContext implements InitializingBean, DisposableBean,
057 ApplicationContextAware, ApplicationListener {
058
059 private static final transient Log LOG = LogFactory.getLog(SpringCamelContext.class);
060 private ApplicationContext applicationContext;
061 private EventEndpoint eventEndpoint;
062 private boolean shouldStartContext =
063 ObjectHelper.getSystemProperty("shouldStartContext", Boolean.TRUE); // start context by default
064
065 public SpringCamelContext() {
066 }
067
068 public SpringCamelContext(ApplicationContext applicationContext) {
069 setApplicationContext(applicationContext);
070 }
071
072 public static SpringCamelContext springCamelContext(ApplicationContext applicationContext) throws Exception {
073 // lets try and look up a configured camel context in the context
074 String[] names = applicationContext.getBeanNamesForType(SpringCamelContext.class);
075 if (names.length == 1) {
076 return (SpringCamelContext)applicationContext.getBean(names[0], SpringCamelContext.class);
077 }
078 SpringCamelContext answer = new SpringCamelContext();
079 answer.setApplicationContext(applicationContext);
080 answer.afterPropertiesSet();
081 return answer;
082 }
083
084 public static SpringCamelContext springCamelContext(String configLocations) throws Exception {
085 return springCamelContext(new ClassPathXmlApplicationContext(configLocations));
086 }
087
088 public void afterPropertiesSet() throws Exception {
089 maybeStart();
090 }
091
092 private void maybeStart() throws Exception {
093 if (!getShouldStartContext()) {
094 LOG.info("Not starting Apache Camel as property ShouldStartContext is false");
095 return;
096 }
097
098 if (!isStarted() && !isStarting()) {
099 // Make sure we will not get into the endless loop of calling star
100 LOG.info("Starting Apache Camel as property ShouldStartContext is true");
101 start();
102 } else {
103 // ignore as Camel is already started
104 LOG.trace("Ignoring maybeStart() as Apache Camel is already started");
105 }
106 }
107
108 public void destroy() throws Exception {
109 stop();
110 }
111
112 public void onApplicationEvent(ApplicationEvent event) {
113 if (LOG.isDebugEnabled()) {
114 LOG.debug("onApplicationEvent: " + event);
115 }
116
117 if (event instanceof ContextRefreshedEvent) {
118 // now lets start the CamelContext so that all its possible
119 // dependencies are initialized
120 try {
121 maybeStart();
122 } catch (RuntimeException e) {
123 throw e;
124 } catch (Exception e) {
125 throw wrapRuntimeCamelException(e);
126 }
127 }
128
129 if (eventEndpoint != null) {
130 eventEndpoint.onApplicationEvent(event);
131 } else {
132 LOG.warn("No spring-event endpoint enabled to handle event: " + event);
133 }
134 }
135
136 // Properties
137 // -----------------------------------------------------------------------
138
139 public ApplicationContext getApplicationContext() {
140 return applicationContext;
141 }
142
143 public void setApplicationContext(ApplicationContext applicationContext) throws BeansException {
144 this.applicationContext = applicationContext;
145
146 if (applicationContext instanceof ConfigurableApplicationContext) {
147 addComponent("spring-event", new EventComponent(applicationContext));
148 }
149 }
150
151 public EventEndpoint getEventEndpoint() {
152 return eventEndpoint;
153 }
154
155 public void setEventEndpoint(EventEndpoint eventEndpoint) {
156 this.eventEndpoint = eventEndpoint;
157 }
158
159 // Implementation methods
160 // -----------------------------------------------------------------------
161
162 @Override
163 protected void doStart() throws Exception {
164 maybeDoStart();
165 }
166
167 protected void maybeDoStart() throws Exception {
168 if (getShouldStartContext()) {
169 super.doStart();
170 if (eventEndpoint == null) {
171 eventEndpoint = createEventEndpoint();
172 }
173 }
174 }
175
176 @Override
177 protected Injector createInjector() {
178 if (applicationContext instanceof ConfigurableApplicationContext) {
179 return new SpringInjector((ConfigurableApplicationContext)applicationContext);
180 } else {
181 LOG.warn("Cannot use SpringInjector as applicationContext is not a ConfigurableApplicationContext as its: "
182 + applicationContext);
183 return super.createInjector();
184 }
185 }
186
187 protected EventEndpoint createEventEndpoint() {
188 return getEndpoint("spring-event:default", EventEndpoint.class);
189 }
190
191 protected Endpoint convertBeanToEndpoint(String uri, Object bean) {
192 // We will use the type convert to build the endpoint first
193 try {
194 Endpoint endpoint = getTypeConverter().convertTo(Endpoint.class, bean);
195 if (endpoint != null) {
196 endpoint.setCamelContext(this);
197 return endpoint;
198 }
199 } catch (NoTypeConversionAvailableException ex) {
200 // ignore, handled below
201 }
202
203 return new ProcessorEndpoint(uri, this, new BeanProcessor(bean, this));
204 }
205
206 @Override
207 protected Registry createRegistry() {
208 return new ApplicationContextRegistry(getApplicationContext());
209 }
210
211 public void setShouldStartContext(boolean shouldStartContext) {
212 this.shouldStartContext = shouldStartContext;
213 }
214
215 public boolean getShouldStartContext() {
216 return shouldStartContext;
217 }
218
219 @Override
220 public String toString() {
221 StringBuilder sb = new StringBuilder();
222 sb.append("SpringCamelContext(").append(getName()).append(")");
223 return sb.toString();
224 }
225
226 }