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.slf4j.Logger;
042 import org.slf4j.LoggerFactory;
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
065 */
066 @XmlRootElement(name = "beanPostProcessor")
067 @XmlAccessorType(XmlAccessType.FIELD)
068 public class CamelBeanPostProcessor implements BeanPostProcessor, ApplicationContextAware {
069 private static final transient Logger LOG = LoggerFactory.getLogger(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 injectFields(bean, beanName);
095 injectMethods(bean, beanName);
096
097 if (bean instanceof CamelContextAware && canSetCamelContext(bean, beanName)) {
098 CamelContextAware contextAware = (CamelContextAware)bean;
099 CamelContext context = getOrLookupCamelContext();
100 if (context == null) {
101 LOG.warn("No CamelContext defined yet so cannot inject into bean: " + beanName);
102 } else {
103 contextAware.setCamelContext(context);
104 }
105 }
106
107 return bean;
108 }
109
110 public Object postProcessAfterInitialization(Object bean, String beanName) throws BeansException {
111 if (LOG.isTraceEnabled()) {
112 LOG.trace("Camel bean processing after initialization for bean: " + beanName);
113 }
114
115 // some beans cannot be post processed at this given time, so we gotta check beforehand
116 if (!canPostProcessBean(bean, beanName)) {
117 return bean;
118 }
119
120 if (bean instanceof DefaultEndpoint) {
121 DefaultEndpoint defaultEndpoint = (DefaultEndpoint) bean;
122 defaultEndpoint.setEndpointUriIfNotSpecified(beanName);
123 }
124
125 return bean;
126 }
127
128 // Properties
129 // -------------------------------------------------------------------------
130
131 public void setApplicationContext(ApplicationContext applicationContext) throws BeansException {
132 this.applicationContext = applicationContext;
133 }
134
135 public CamelContext getCamelContext() {
136 return camelContext;
137 }
138
139 public void setCamelContext(CamelContext camelContext) {
140 this.camelContext = camelContext;
141 }
142
143 public String getCamelId() {
144 return camelId;
145 }
146
147 public void setCamelId(String camelId) {
148 this.camelId = camelId;
149 }
150
151 // Implementation methods
152 // -------------------------------------------------------------------------
153
154 /**
155 * Can we post process the given bean?
156 *
157 * @param bean the bean
158 * @param beanName the bean name
159 * @return true to process it
160 */
161 protected boolean canPostProcessBean(Object bean, String beanName) {
162 // the JMXAgent is a bit strange and causes Spring issues if we let it being
163 // post processed by this one. It does not need it anyway so we are good to go.
164 if (bean instanceof CamelJMXAgentDefinition) {
165 return false;
166 }
167
168 // all other beans can of course be processed
169 return true;
170 }
171
172
173 protected boolean canSetCamelContext(Object bean, String beanName) {
174 if (bean instanceof CamelContextAware) {
175 CamelContextAware camelContextAware = (CamelContextAware) bean;
176 CamelContext context = camelContextAware.getCamelContext();
177 if (context != null) {
178 if (LOG.isTraceEnabled()) {
179 LOG.trace("CamelContext already set on bean with id [" + beanName + "]. Will keep existing CamelContext on bean.");
180 }
181 return false;
182 }
183 }
184
185 return true;
186 }
187
188 /**
189 * A strategy method to allow implementations to perform some custom JBI
190 * based injection of the POJO
191 *
192 * @param bean the bean to be injected
193 */
194 protected void injectFields(final Object bean, final String beanName) {
195 ReflectionUtils.doWithFields(bean.getClass(), new ReflectionUtils.FieldCallback() {
196 public void doWith(Field field) throws IllegalArgumentException, IllegalAccessException {
197 EndpointInject endpointInject = field.getAnnotation(EndpointInject.class);
198 if (endpointInject != null && getPostProcessor().matchContext(endpointInject.context())) {
199 injectField(field, endpointInject.uri(), endpointInject.ref(), bean, beanName);
200 }
201
202 Produce produce = field.getAnnotation(Produce.class);
203 if (produce != null && getPostProcessor().matchContext(produce.context())) {
204 injectField(field, produce.uri(), produce.ref(), bean, beanName);
205 }
206 }
207 });
208 }
209
210 protected void injectField(Field field, String endpointUri, String endpointRef, Object bean, String beanName) {
211 ReflectionUtils.setField(field, bean, getPostProcessor().getInjectionValue(field.getType(), endpointUri, endpointRef, field.getName(), bean, beanName));
212 }
213
214 protected void injectMethods(final Object bean, final String beanName) {
215 ReflectionUtils.doWithMethods(bean.getClass(), new ReflectionUtils.MethodCallback() {
216 public void doWith(Method method) throws IllegalArgumentException, IllegalAccessException {
217 setterInjection(method, bean, beanName);
218 getPostProcessor().consumerInjection(method, bean, beanName);
219 }
220 });
221 }
222
223 protected void setterInjection(Method method, Object bean, String beanName) {
224 EndpointInject endpointInject = method.getAnnotation(EndpointInject.class);
225 if (endpointInject != null && getPostProcessor().matchContext(endpointInject.context())) {
226 setterInjection(method, bean, beanName, endpointInject.uri(), endpointInject.ref());
227 }
228
229 Produce produce = method.getAnnotation(Produce.class);
230 if (produce != null && getPostProcessor().matchContext(produce.context())) {
231 setterInjection(method, bean, beanName, produce.uri(), produce.ref());
232 }
233 }
234
235 protected void setterInjection(Method method, Object bean, String beanName, String endpointUri, String endpointRef) {
236 Class<?>[] parameterTypes = method.getParameterTypes();
237 if (parameterTypes != null) {
238 if (parameterTypes.length != 1) {
239 LOG.warn("Ignoring badly annotated method for injection due to incorrect number of parameters: " + method);
240 } else {
241 String propertyName = ObjectHelper.getPropertyName(method);
242 Object value = getPostProcessor().getInjectionValue(parameterTypes[0], endpointUri, endpointRef, propertyName, bean, beanName);
243 ObjectHelper.invokeMethod(method, bean, value);
244 }
245 }
246 }
247
248 protected CamelContext getOrLookupCamelContext() {
249 if (camelContext == null && applicationContext.containsBean(camelId)) {
250 camelContext = (CamelContext) applicationContext.getBean(camelId);
251 }
252 return camelContext;
253 }
254
255 public CamelPostProcessorHelper getPostProcessor() {
256 // lets lazily create the post processor
257 if (postProcessor == null) {
258 postProcessor = new CamelPostProcessorHelper() {
259
260 @Override
261 public CamelContext getCamelContext() {
262 // lets lazily lookup the camel context here
263 // as doing this will cause this context to be started immediately
264 // breaking the lifecycle ordering of different camel contexts
265 // so we only want to do this on demand
266 return getOrLookupCamelContext();
267 }
268
269 @Override
270 protected RuntimeException createProxyInstantiationRuntimeException(Class<?> type, Endpoint endpoint, Exception e) {
271 return new BeanInstantiationException(type, "Could not instantiate proxy of type " + type.getName() + " on endpoint " + endpoint, e);
272 }
273
274 protected boolean isSingleton(Object bean, String beanName) {
275 // no application context has been injected which means the bean
276 // has not been enlisted in Spring application context
277 if (applicationContext == null || beanName == null) {
278 return super.isSingleton(bean, beanName);
279 } else {
280 return applicationContext.isSingleton(beanName);
281 }
282 }
283
284 protected void startService(Service service, Object bean, String beanName) throws Exception {
285 if (isSingleton(bean, beanName)) {
286 getCamelContext().addService(service);
287 } else {
288 // only start service and do not add it to CamelContext
289 ServiceHelper.startService(service);
290 if (prototypeBeans.add(beanName)) {
291 // do not spam the log with WARN so do this only once per bean name
292 LOG.warn("The bean with id [" + beanName + "] is prototype scoped and cannot stop the injected service when bean is destroyed: "
293 + service + ". You may want to stop the service manually from the bean.");
294 }
295 }
296 }
297 };
298 }
299 return postProcessor;
300 }
301
302 }