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.Processor;
021    import org.apache.camel.RuntimeCamelException;
022    import org.apache.camel.component.bean.BeanProcessor;
023    import org.apache.camel.component.event.EventComponent;
024    import org.apache.camel.component.event.EventEndpoint;
025    import org.apache.camel.impl.DefaultCamelContext;
026    import org.apache.camel.impl.ProcessorEndpoint;
027    import org.apache.camel.spi.ComponentResolver;
028    import org.apache.camel.spi.Injector;
029    import org.apache.camel.spi.Registry;
030    import org.apache.camel.spring.spi.ApplicationContextRegistry;
031    import org.apache.camel.spring.spi.SpringComponentResolver;
032    import org.apache.camel.spring.spi.SpringInjector;
033    import org.apache.commons.logging.Log;
034    import org.apache.commons.logging.LogFactory;
035    
036    import org.springframework.beans.BeansException;
037    import org.springframework.beans.factory.DisposableBean;
038    import org.springframework.beans.factory.InitializingBean;
039    import org.springframework.context.ApplicationContext;
040    import org.springframework.context.ApplicationContextAware;
041    import org.springframework.context.ApplicationEvent;
042    import org.springframework.context.ApplicationListener;
043    import org.springframework.context.ConfigurableApplicationContext;
044    import org.springframework.context.event.ContextRefreshedEvent;
045    import org.springframework.context.support.AbstractRefreshableApplicationContext;
046    import org.springframework.context.support.ClassPathXmlApplicationContext;
047    
048    /**
049     * A Spring aware implementation of {@link CamelContext} which will
050     * automatically register itself with Springs lifecycle methods plus allows
051     * spring to be used to customize a any <a
052     * href="http://activemq.apache.org/camel/type-converter.html">Type Converters</a>
053     * as well as supporting accessing components and beans via the Spring
054     * {@link ApplicationContext}
055     * 
056     * @version $Revision: 563665 $
057     */
058    public class SpringCamelContext extends DefaultCamelContext implements InitializingBean, DisposableBean, ApplicationContextAware, ApplicationListener {
059        private static final transient Log LOG = LogFactory.getLog(SpringCamelContext.class);
060        private ApplicationContext applicationContext;
061        private EventEndpoint eventEndpoint;
062    
063        public SpringCamelContext() {
064        }
065    
066        public SpringCamelContext(ApplicationContext applicationContext) {
067            setApplicationContext(applicationContext);
068        }
069    
070        public static SpringCamelContext springCamelContext(ApplicationContext applicationContext) throws Exception {
071            // lets try and look up a configured camel context in the context
072            String[] names = applicationContext.getBeanNamesForType(SpringCamelContext.class);
073            if (names.length == 1) {
074                return (SpringCamelContext)applicationContext.getBean(names[0], SpringCamelContext.class);
075            }
076            SpringCamelContext answer = new SpringCamelContext();
077            answer.setApplicationContext(applicationContext);
078            answer.afterPropertiesSet();
079            return answer;
080        }
081    
082        public static SpringCamelContext springCamelContext(String configLocations) throws Exception {
083            return springCamelContext(new ClassPathXmlApplicationContext(configLocations));
084        }
085    
086        public void afterPropertiesSet() throws Exception {
087            start();
088        }
089    
090        public void destroy() throws Exception {
091            stop();
092        }
093    
094        public void onApplicationEvent(ApplicationEvent event) {
095            if (LOG.isDebugEnabled()) {
096                LOG.debug("Publishing event: " + event);
097            }
098    
099            if (event instanceof ContextRefreshedEvent) {
100                // now lets start the CamelContext so that all its possible
101                // dependencies are initailized
102                try {
103                    LOG.debug("Starting the CamelContext now that the ApplicationContext has started");
104                    start();
105                } catch (Exception e) {
106                    throw new RuntimeCamelException(e);
107                }
108                if (eventEndpoint != null) {
109                    eventEndpoint.onApplicationEvent(event);
110                }
111            } else {
112                if (eventEndpoint != null) {
113                    eventEndpoint.onApplicationEvent(event);
114                } else {
115                    LOG.warn("No eventEndpoint enabled for event: " + event);
116                }
117            }
118        }
119    
120        // Properties
121        // -----------------------------------------------------------------------
122    
123        public ApplicationContext getApplicationContext() {
124            return applicationContext;
125        }
126    
127        public void setApplicationContext(ApplicationContext applicationContext) throws BeansException {
128            this.applicationContext = applicationContext;
129    
130            if (applicationContext instanceof ConfigurableApplicationContext) {
131                addComponent("event", new EventComponent(applicationContext));
132            }
133        }
134    
135        public EventEndpoint getEventEndpoint() {
136            return eventEndpoint;
137        }
138    
139        public void setEventEndpoint(EventEndpoint eventEndpoint) {
140            this.eventEndpoint = eventEndpoint;
141        }
142    
143        // Implementation methods
144        // -----------------------------------------------------------------------
145    
146        @Override
147        protected void doStart() throws Exception {
148            super.doStart();
149            if (eventEndpoint == null) {
150                eventEndpoint = createEventEndpoint();
151            }
152        }
153    
154        @Override
155        protected Injector createInjector() {
156            return new SpringInjector((AbstractRefreshableApplicationContext)getApplicationContext());
157        }
158    
159        @Override
160        protected ComponentResolver createComponentResolver() {
161            ComponentResolver defaultResolver = super.createComponentResolver();
162            return new SpringComponentResolver(getApplicationContext(), defaultResolver);
163        }
164    
165        protected EventEndpoint createEventEndpoint() {
166            EventEndpoint endpoint = getEndpoint("event:default", EventEndpoint.class);
167            return endpoint;
168        }
169    
170        protected Endpoint convertBeanToEndpoint(String uri, Object bean) {
171            Processor processor = new BeanProcessor(bean, this);
172            return new ProcessorEndpoint(uri, this, processor);
173        }
174    
175        @Override
176        protected Registry createRegistry() {
177            return new ApplicationContextRegistry(getApplicationContext());
178        }
179    }