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
022 import javax.xml.bind.annotation.XmlAccessType;
023 import javax.xml.bind.annotation.XmlAccessorType;
024 import javax.xml.bind.annotation.XmlRootElement;
025 import javax.xml.bind.annotation.XmlTransient;
026
027 import org.apache.camel.CamelContext;
028 import org.apache.camel.CamelContextAware;
029 import org.apache.camel.Endpoint;
030 import org.apache.camel.EndpointInject;
031 import org.apache.camel.Produce;
032 import org.apache.camel.impl.CamelPostProcessorHelper;
033 import org.apache.camel.impl.DefaultEndpoint;
034 import org.apache.camel.spring.util.ReflectionUtils;
035 import org.apache.camel.util.ObjectHelper;
036 import org.apache.commons.logging.Log;
037 import org.apache.commons.logging.LogFactory;
038 import org.springframework.beans.BeanInstantiationException;
039 import org.springframework.beans.BeansException;
040 import org.springframework.beans.factory.config.BeanPostProcessor;
041 import org.springframework.context.ApplicationContext;
042 import org.springframework.context.ApplicationContextAware;
043
044 /**
045 * A bean post processor which implements the <a href="http://camel.apache.org/bean-integration.html">Bean Integration</a>
046 * features in Camel. Features such as the <a href="http://camel.apache.org/bean-injection.html">Bean Injection</a> of objects like
047 * {@link Endpoint} and
048 * {@link org.apache.camel.ProducerTemplate} together with support for
049 * <a href="http://camel.apache.org/pojo-consuming.html">POJO Consuming</a> via the
050 * {@link org.apache.camel.Consume} annotation along with
051 * <a href="http://camel.apache.org/pojo-producing.html">POJO Producing</a> via the
052 * {@link org.apache.camel.Produce} annotation along with other annotations such as
053 * {@link org.apache.camel.RecipientList} for creating <a href="http://camel.apache.org/recipientlist-annotation.html">a Recipient List router via annotations</a>.
054 * <p>
055 * If you use the <camelContext> element in your <a href="http://camel.apache.org/spring.html">Spring XML</a>
056 * then one of these bean post processors is implicitly installed and configured for you. So you should never have to
057 * explicitly create or configure one of these instances.
058 *
059 * @version $Revision: 800683 $
060 */
061 @XmlRootElement(name = "beanPostProcessor")
062 @XmlAccessorType(XmlAccessType.FIELD)
063 public class CamelBeanPostProcessor implements BeanPostProcessor, ApplicationContextAware {
064 private static final transient Log LOG = LogFactory.getLog(CamelBeanPostProcessor.class);
065 @XmlTransient
066 private CamelContext camelContext;
067 @XmlTransient
068 private ApplicationContext applicationContext;
069 @XmlTransient
070 private CamelPostProcessorHelper postProcessor;
071 @XmlTransient
072 private String camelId;
073
074 public CamelBeanPostProcessor() {
075 }
076
077 public Object postProcessBeforeInitialization(Object bean, String beanName) throws BeansException {
078 if (LOG.isTraceEnabled()) {
079 LOG.trace("Camel bean processing before initialization for bean: " + beanName);
080 }
081
082 // some beans cannot be post processed at this given time, so we gotta check beforehand
083 if (!canPostProcessBean(bean, beanName)) {
084 return bean;
085 }
086
087 if (camelContext == null && applicationContext.containsBean(camelId)) {
088 setCamelContext((CamelContext) applicationContext.getBean(camelId));
089 }
090
091 injectFields(bean);
092 injectMethods(bean);
093
094 if (bean instanceof CamelContextAware && canSetCamelContext(bean, beanName)) {
095 CamelContextAware contextAware = (CamelContextAware)bean;
096 if (camelContext == null) {
097 LOG.warn("No CamelContext defined yet so cannot inject into: " + bean);
098 } else {
099 contextAware.setCamelContext(camelContext);
100 }
101 }
102
103 return bean;
104 }
105
106 public Object postProcessAfterInitialization(Object bean, String beanName) throws BeansException {
107 if (LOG.isTraceEnabled()) {
108 LOG.trace("Camel bean processing after initialization for bean: " + beanName);
109 }
110
111 // some beans cannot be post processed at this given time, so we gotta check beforehand
112 if (!canPostProcessBean(bean, beanName)) {
113 return bean;
114 }
115
116 if (bean instanceof DefaultEndpoint) {
117 DefaultEndpoint defaultEndpoint = (DefaultEndpoint) bean;
118 defaultEndpoint.setEndpointUriIfNotSpecified(beanName);
119 }
120
121 return bean;
122 }
123
124 // Properties
125 // -------------------------------------------------------------------------
126
127 public void setApplicationContext(ApplicationContext applicationContext) throws BeansException {
128 this.applicationContext = applicationContext;
129 }
130
131 public CamelContext getCamelContext() {
132 return camelContext;
133 }
134
135 public void setCamelContext(CamelContext camelContext) {
136 this.camelContext = camelContext;
137 postProcessor = new CamelPostProcessorHelper(camelContext) {
138 @Override
139 protected RuntimeException createProxyInstantiationRuntimeException(Class<?> type, Endpoint endpoint, Exception e) {
140 return new BeanInstantiationException(type, "Could not instantiate proxy of type " + type.getName() + " on endpoint " + endpoint, e);
141 }
142 };
143 }
144
145 public String getCamelId() {
146 return camelId;
147 }
148
149 public void setCamelId(String camelId) {
150 this.camelId = camelId;
151 }
152
153 // Implementation methods
154 // -------------------------------------------------------------------------
155
156 /**
157 * Can we post process the given bean?
158 *
159 * @param bean the bean
160 * @param beanName the bean name
161 * @return true to process it
162 */
163 protected boolean canPostProcessBean(Object bean, String beanName) {
164 // the JMXAgent is a bit strange and causes Spring issues if we let it being
165 // post processed by this one. It does not need it anyway so we are good to go.
166 if (bean instanceof CamelJMXAgentDefinition) {
167 return false;
168 }
169
170 // all other beans can of course be processed
171 return true;
172 }
173
174
175 protected boolean canSetCamelContext(Object bean, String beanName) {
176 boolean answer = true;
177 if (bean instanceof CamelContextAware) {
178 CamelContextAware camelContextAware = (CamelContextAware) bean;
179 CamelContext context = camelContextAware.getCamelContext();
180 if (context != null) {
181 if (LOG.isTraceEnabled()) {
182 LOG.trace("The camel context of " + beanName + " is set, so we skip inject the camel context of it.");
183 }
184 answer = false;
185 }
186 } else {
187 answer = false;
188 }
189 return answer;
190 }
191
192 /**
193 * A strategy method to allow implementations to perform some custom JBI
194 * based injection of the POJO
195 *
196 * @param bean the bean to be injected
197 */
198 protected void injectFields(final Object bean) {
199 ReflectionUtils.doWithFields(bean.getClass(), new ReflectionUtils.FieldCallback() {
200 public void doWith(Field field) throws IllegalArgumentException, IllegalAccessException {
201 EndpointInject endpointInject = field.getAnnotation(EndpointInject.class);
202 if (endpointInject != null && postProcessor.matchContext(endpointInject.context())) {
203 injectField(field, endpointInject.uri(), endpointInject.name(), bean);
204 }
205
206 Produce produce = field.getAnnotation(Produce.class);
207 if (produce != null && postProcessor.matchContext(produce.context())) {
208 injectField(field, produce.uri(), produce.ref(), bean);
209 }
210 }
211 });
212 }
213
214 protected void injectField(Field field, String endpointUri, String endpointRef, Object bean) {
215 ReflectionUtils.setField(field, bean, getPostProcessor().getInjectionValue(field.getType(), endpointUri, endpointRef, field.getName()));
216 }
217
218 protected void injectMethods(final Object bean) {
219 ReflectionUtils.doWithMethods(bean.getClass(), new ReflectionUtils.MethodCallback() {
220 @SuppressWarnings("unchecked")
221 public void doWith(Method method) throws IllegalArgumentException, IllegalAccessException {
222 setterInjection(method, bean);
223 getPostProcessor().consumerInjection(method, bean);
224 }
225 });
226 }
227
228 protected void setterInjection(Method method, Object bean) {
229 EndpointInject endpointInject = method.getAnnotation(EndpointInject.class);
230 if (endpointInject != null && postProcessor.matchContext(endpointInject.context())) {
231 setterInjection(method, bean, endpointInject.uri(), endpointInject.name());
232 }
233
234 Produce produce = method.getAnnotation(Produce.class);
235 if (produce != null && postProcessor.matchContext(produce.context())) {
236 setterInjection(method, bean, produce.uri(), produce.ref());
237 }
238 }
239
240 protected void setterInjection(Method method, Object bean, String endpointUri, String endpointRef) {
241 Class<?>[] parameterTypes = method.getParameterTypes();
242 if (parameterTypes != null) {
243 if (parameterTypes.length != 1) {
244 LOG.warn("Ignoring badly annotated method for injection due to incorrect number of parameters: " + method);
245 } else {
246 String propertyName = ObjectHelper.getPropertyName(method);
247 Object value = getPostProcessor().getInjectionValue(parameterTypes[0], endpointUri, endpointRef, propertyName);
248 ObjectHelper.invokeMethod(method, bean, value);
249 }
250 }
251 }
252
253 public CamelPostProcessorHelper getPostProcessor() {
254 ObjectHelper.notNull(postProcessor, "postProcessor");
255 return postProcessor;
256 }
257
258 }