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 java.lang.reflect.Field;
020 import java.lang.reflect.Method;
021 import java.util.LinkedHashSet;
022 import java.util.Set;
023
024 import javax.xml.bind.annotation.XmlAccessType;
025 import javax.xml.bind.annotation.XmlAccessorType;
026 import javax.xml.bind.annotation.XmlRootElement;
027 import javax.xml.bind.annotation.XmlTransient;
028
029 import org.apache.camel.CamelContext;
030 import org.apache.camel.CamelContextAware;
031 import org.apache.camel.Endpoint;
032 import org.apache.camel.EndpointInject;
033 import org.apache.camel.Produce;
034 import org.apache.camel.Service;
035 import org.apache.camel.core.xml.CamelJMXAgentDefinition;
036 import org.apache.camel.impl.CamelPostProcessorHelper;
037 import org.apache.camel.impl.DefaultEndpoint;
038 import org.apache.camel.spring.util.ReflectionUtils;
039 import org.apache.camel.util.ObjectHelper;
040 import org.apache.camel.util.ServiceHelper;
041 import org.apache.commons.logging.Log;
042 import org.apache.commons.logging.LogFactory;
043 import org.springframework.beans.BeanInstantiationException;
044 import org.springframework.beans.BeansException;
045 import org.springframework.beans.factory.config.BeanPostProcessor;
046 import org.springframework.context.ApplicationContext;
047 import org.springframework.context.ApplicationContextAware;
048
049 /**
050 * A bean post processor which implements the <a href="http://camel.apache.org/bean-integration.html">Bean Integration</a>
051 * features in Camel. Features such as the <a href="http://camel.apache.org/bean-injection.html">Bean Injection</a> of objects like
052 * {@link Endpoint} and
053 * {@link org.apache.camel.ProducerTemplate} together with support for
054 * <a href="http://camel.apache.org/pojo-consuming.html">POJO Consuming</a> via the
055 * {@link org.apache.camel.Consume} annotation along with
056 * <a href="http://camel.apache.org/pojo-producing.html">POJO Producing</a> via the
057 * {@link org.apache.camel.Produce} annotation along with other annotations such as
058 * {@link org.apache.camel.RecipientList} for creating <a href="http://camel.apache.org/recipientlist-annotation.html">a Recipient List router via annotations</a>.
059 * <p>
060 * If you use the <camelContext> element in your <a href="http://camel.apache.org/spring.html">Spring XML</a>
061 * then one of these bean post processors is implicitly installed and configured for you. So you should never have to
062 * explicitly create or configure one of these instances.
063 *
064 * @version $Revision: 1044221 $
065 */
066 @XmlRootElement(name = "beanPostProcessor")
067 @XmlAccessorType(XmlAccessType.FIELD)
068 public class CamelBeanPostProcessor implements BeanPostProcessor, ApplicationContextAware {
069 private static final transient Log LOG = LogFactory.getLog(CamelBeanPostProcessor.class);
070 @XmlTransient
071 Set<String> prototypeBeans = new LinkedHashSet<String>();
072 @XmlTransient
073 private CamelContext camelContext;
074 @XmlTransient
075 private ApplicationContext applicationContext;
076 @XmlTransient
077 private CamelPostProcessorHelper postProcessor;
078 @XmlTransient
079 private String camelId;
080
081 public CamelBeanPostProcessor() {
082 }
083
084 public Object postProcessBeforeInitialization(Object bean, String beanName) throws BeansException {
085 if (LOG.isTraceEnabled()) {
086 LOG.trace("Camel bean processing before initialization for bean: " + beanName);
087 }
088
089 // some beans cannot be post processed at this given time, so we gotta check beforehand
090 if (!canPostProcessBean(bean, beanName)) {
091 return bean;
092 }
093
094 if (camelContext == null && applicationContext.containsBean(camelId)) {
095 setCamelContext((CamelContext) applicationContext.getBean(camelId));
096 }
097
098 injectFields(bean, beanName);
099 injectMethods(bean, beanName);
100
101 if (bean instanceof CamelContextAware && canSetCamelContext(bean, beanName)) {
102 CamelContextAware contextAware = (CamelContextAware)bean;
103 if (camelContext == null) {
104 LOG.warn("No CamelContext defined yet so cannot inject into bean: " + beanName);
105 } else {
106 contextAware.setCamelContext(camelContext);
107 }
108 }
109
110 return bean;
111 }
112
113 public Object postProcessAfterInitialization(Object bean, String beanName) throws BeansException {
114 if (LOG.isTraceEnabled()) {
115 LOG.trace("Camel bean processing after initialization for bean: " + beanName);
116 }
117
118 // some beans cannot be post processed at this given time, so we gotta check beforehand
119 if (!canPostProcessBean(bean, beanName)) {
120 return bean;
121 }
122
123 if (bean instanceof DefaultEndpoint) {
124 DefaultEndpoint defaultEndpoint = (DefaultEndpoint) bean;
125 defaultEndpoint.setEndpointUriIfNotSpecified(beanName);
126 }
127
128 return bean;
129 }
130
131 // Properties
132 // -------------------------------------------------------------------------
133
134 public void setApplicationContext(ApplicationContext applicationContext) throws BeansException {
135 this.applicationContext = applicationContext;
136 }
137
138 public CamelContext getCamelContext() {
139 return camelContext;
140 }
141
142 public void setCamelContext(CamelContext camelContext) {
143 this.camelContext = camelContext;
144 postProcessor = new CamelPostProcessorHelper(camelContext) {
145 @Override
146 protected RuntimeException createProxyInstantiationRuntimeException(Class<?> type, Endpoint endpoint, Exception e) {
147 return new BeanInstantiationException(type, "Could not instantiate proxy of type " + type.getName() + " on endpoint " + endpoint, e);
148 }
149
150 protected boolean isSingleton(Object bean, String beanName) {
151 // no application context has been injected which means the bean
152 // has not been enlisted in Spring application context
153 if (applicationContext == null || beanName == null) {
154 return super.isSingleton(bean, beanName);
155 } else {
156 return applicationContext.isSingleton(beanName);
157 }
158 }
159
160 protected void startService(Service service, Object bean, String beanName) throws Exception {
161 if (isSingleton(bean, beanName)) {
162 getCamelContext().addService(service);
163 } else {
164 // only start service and do not add it to CamelContext
165 ServiceHelper.startService(service);
166 if (prototypeBeans.add(beanName)) {
167 // do not spam the log with WARN so do this only once per bean name
168 LOG.warn("The bean with id [" + beanName + "] is prototype scoped and cannot stop the injected service when bean is destroyed: "
169 + service + ". You may want to stop the service manually from the bean.");
170 }
171 }
172 }
173 };
174 }
175
176 public String getCamelId() {
177 return camelId;
178 }
179
180 public void setCamelId(String camelId) {
181 this.camelId = camelId;
182 }
183
184 // Implementation methods
185 // -------------------------------------------------------------------------
186
187 /**
188 * Can we post process the given bean?
189 *
190 * @param bean the bean
191 * @param beanName the bean name
192 * @return true to process it
193 */
194 protected boolean canPostProcessBean(Object bean, String beanName) {
195 // the JMXAgent is a bit strange and causes Spring issues if we let it being
196 // post processed by this one. It does not need it anyway so we are good to go.
197 if (bean instanceof CamelJMXAgentDefinition) {
198 return false;
199 }
200
201 // all other beans can of course be processed
202 return true;
203 }
204
205
206 protected boolean canSetCamelContext(Object bean, String beanName) {
207 if (bean instanceof CamelContextAware) {
208 CamelContextAware camelContextAware = (CamelContextAware) bean;
209 CamelContext context = camelContextAware.getCamelContext();
210 if (context != null) {
211 if (LOG.isTraceEnabled()) {
212 LOG.trace("CamelContext already set on bean with id [" + beanName + "]. Will keep existing CamelContext on bean.");
213 }
214 return false;
215 }
216 }
217
218 return true;
219 }
220
221 /**
222 * A strategy method to allow implementations to perform some custom JBI
223 * based injection of the POJO
224 *
225 * @param bean the bean to be injected
226 */
227 protected void injectFields(final Object bean, final String beanName) {
228 ReflectionUtils.doWithFields(bean.getClass(), new ReflectionUtils.FieldCallback() {
229 public void doWith(Field field) throws IllegalArgumentException, IllegalAccessException {
230 EndpointInject endpointInject = field.getAnnotation(EndpointInject.class);
231 if (endpointInject != null && postProcessor.matchContext(endpointInject.context())) {
232 injectField(field, endpointInject.uri(), endpointInject.ref(), bean, beanName);
233 }
234
235 Produce produce = field.getAnnotation(Produce.class);
236 if (produce != null && postProcessor.matchContext(produce.context())) {
237 injectField(field, produce.uri(), produce.ref(), bean, beanName);
238 }
239 }
240 });
241 }
242
243 protected void injectField(Field field, String endpointUri, String endpointRef, Object bean, String beanName) {
244 ReflectionUtils.setField(field, bean, getPostProcessor().getInjectionValue(field.getType(), endpointUri, endpointRef, field.getName(), bean, beanName));
245 }
246
247 protected void injectMethods(final Object bean, final String beanName) {
248 ReflectionUtils.doWithMethods(bean.getClass(), new ReflectionUtils.MethodCallback() {
249 public void doWith(Method method) throws IllegalArgumentException, IllegalAccessException {
250 setterInjection(method, bean, beanName);
251 getPostProcessor().consumerInjection(method, bean, beanName);
252 }
253 });
254 }
255
256 protected void setterInjection(Method method, Object bean, String beanName) {
257 EndpointInject endpointInject = method.getAnnotation(EndpointInject.class);
258 if (endpointInject != null && postProcessor.matchContext(endpointInject.context())) {
259 setterInjection(method, bean, beanName, endpointInject.uri(), endpointInject.ref());
260 }
261
262 Produce produce = method.getAnnotation(Produce.class);
263 if (produce != null && postProcessor.matchContext(produce.context())) {
264 setterInjection(method, bean, beanName, produce.uri(), produce.ref());
265 }
266 }
267
268 protected void setterInjection(Method method, Object bean, String beanName, String endpointUri, String endpointRef) {
269 Class<?>[] parameterTypes = method.getParameterTypes();
270 if (parameterTypes != null) {
271 if (parameterTypes.length != 1) {
272 LOG.warn("Ignoring badly annotated method for injection due to incorrect number of parameters: " + method);
273 } else {
274 String propertyName = ObjectHelper.getPropertyName(method);
275 Object value = getPostProcessor().getInjectionValue(parameterTypes[0], endpointUri, endpointRef, propertyName, bean, beanName);
276 ObjectHelper.invokeMethod(method, bean, value);
277 }
278 }
279 }
280
281 public CamelPostProcessorHelper getPostProcessor() {
282 ObjectHelper.notNull(postProcessor, "postProcessor");
283 return postProcessor;
284 }
285
286 }