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.CamelContextAware;
028 import org.apache.camel.Endpoint;
029 import org.apache.camel.EndpointInject;
030 import org.apache.camel.Produce;
031 import org.apache.camel.impl.CamelPostProcessorHelper;
032 import org.apache.camel.spring.util.ReflectionUtils;
033 import org.apache.camel.util.ObjectHelper;
034 import org.apache.commons.logging.Log;
035 import org.apache.commons.logging.LogFactory;
036 import org.springframework.beans.BeanInstantiationException;
037 import org.springframework.beans.BeansException;
038 import org.springframework.beans.factory.config.BeanPostProcessor;
039 import org.springframework.context.ApplicationContext;
040 import org.springframework.context.ApplicationContextAware;
041
042 /**
043 * A bean post processor which implements the <a href="http://activemq.apache.org/camel/bean-integration.html">Bean Integration</a>
044 * features in Camel such as the <a href="http://activemq.apache.org/camel/bean-injection.html">Bean Injection</a> of objects like
045 * {@link Endpoint} and
046 * {@link org.apache.camel.ProducerTemplate} together with support for
047 * <a href="http://activemq.apache.org/camel/pojo-consuming.html">POJO Consuming</a> via the
048 * {@link org.apache.camel.Consume} and {@link org.apache.camel.MessageDriven} annotations along with
049 * <a href="http://activemq.apache.org/camel/pojo-producing.html">POJO Producing</a> via the
050 * {@link org.apache.camel.Produce} annotation along with other annotations such as
051 * {@link org.apache.camel.RecipientList} for creating <a href="http://activemq.apache.org/camel/recipientlist-annotation.html">a Recipient List router via annotations</a>.
052 * <p>
053 * If you use the <camelContext> element in your <a href="http://activemq.apache.org/camel/spring.html">Spring XML</a>
054 * then one of these bean post processors is implicity installed and configured for you. So you should never have to
055 * explicitly create or configure one of these instances.
056 *
057 * @version $Revision: 707305 $
058 */
059 @XmlRootElement(name = "beanPostProcessor")
060 @XmlAccessorType(XmlAccessType.FIELD)
061 public class CamelBeanPostProcessor implements BeanPostProcessor, ApplicationContextAware {
062 private static final transient Log LOG = LogFactory.getLog(CamelBeanPostProcessor.class);
063 @XmlTransient
064 private SpringCamelContext camelContext;
065 @XmlTransient
066 private ApplicationContext applicationContext;
067 @XmlTransient
068 private CamelPostProcessorHelper postProcessor;
069
070 public CamelBeanPostProcessor() {
071 }
072
073 public Object postProcessBeforeInitialization(Object bean, String beanName) throws BeansException {
074 injectFields(bean);
075 injectMethods(bean);
076 if (bean instanceof CamelContextAware) {
077 CamelContextAware contextAware = (CamelContextAware)bean;
078 if (camelContext == null) {
079 LOG.warn("No CamelContext defined yet so cannot inject into: " + bean);
080 } else {
081 contextAware.setCamelContext(camelContext);
082 }
083 }
084 return bean;
085 }
086
087 public Object postProcessAfterInitialization(Object bean, String beanName) throws BeansException {
088 return bean;
089 }
090
091 // Properties
092 // -------------------------------------------------------------------------
093
094 public void setApplicationContext(ApplicationContext applicationContext) throws BeansException {
095 this.applicationContext = applicationContext;
096 }
097
098 public SpringCamelContext getCamelContext() {
099 return camelContext;
100 }
101
102 public void setCamelContext(SpringCamelContext camelContext) {
103 this.camelContext = camelContext;
104 postProcessor = new CamelPostProcessorHelper(camelContext) {
105 @Override
106 protected RuntimeException createProxyInstantiationRuntimeException(Class<?> type, Endpoint endpoint, Exception e) {
107 return new BeanInstantiationException(type, "Could not instantiate proxy of type " + type.getName() + " on endpoint " + endpoint, e);
108 }
109 };
110 }
111
112 // Implementation methods
113 // -------------------------------------------------------------------------
114
115 /**
116 * A strategy method to allow implementations to perform some custom JBI
117 * based injection of the POJO
118 *
119 * @param bean the bean to be injected
120 */
121 protected void injectFields(final Object bean) {
122 ReflectionUtils.doWithFields(bean.getClass(), new ReflectionUtils.FieldCallback() {
123 public void doWith(Field field) throws IllegalArgumentException, IllegalAccessException {
124 EndpointInject annotation = field.getAnnotation(EndpointInject.class);
125 if (annotation != null) {
126 injectField(field, annotation.uri(), annotation.name(), bean);
127 }
128 Produce produce = field.getAnnotation(Produce.class);
129 if (produce != null) {
130 injectField(field, produce.uri(), produce.ref(), bean);
131 }
132 }
133 });
134 }
135
136 protected void injectField(Field field, String endpointUri, String endpointRef, Object bean) {
137 ReflectionUtils.setField(field, bean, getPostProcessor().getInjectionValue(field.getType(), endpointUri, endpointRef, field.getName()));
138 }
139
140 protected void injectMethods(final Object bean) {
141 ReflectionUtils.doWithMethods(bean.getClass(), new ReflectionUtils.MethodCallback() {
142 @SuppressWarnings("unchecked")
143 public void doWith(Method method) throws IllegalArgumentException, IllegalAccessException {
144 setterInjection(method, bean);
145 getPostProcessor().consumerInjection(method, bean);
146 }
147 });
148 }
149
150 protected void setterInjection(Method method, Object bean) {
151 EndpointInject annoation = method.getAnnotation(EndpointInject.class);
152 if (annoation != null) {
153 setterInjection(method, bean, annoation.uri(), annoation.name());
154 }
155 Produce produce = method.getAnnotation(Produce.class);
156 if (produce != null) {
157 setterInjection(method, bean, produce.uri(), produce.ref());
158 }
159 }
160
161 protected void setterInjection(Method method, Object bean, String endpointUri, String endpointRef) {
162 Class<?>[] parameterTypes = method.getParameterTypes();
163 if (parameterTypes != null) {
164 if (parameterTypes.length != 1) {
165 LOG.warn("Ignoring badly annotated method for injection due to incorrect number of parameters: " + method);
166 } else {
167 String propertyName = ObjectHelper.getPropertyName(method);
168 Object value = getPostProcessor().getInjectionValue(parameterTypes[0], endpointUri, endpointRef, propertyName);
169 ObjectHelper.invokeMethod(method, bean, value);
170 }
171 }
172 }
173
174
175 protected void consumerInjection(final Object bean) {
176 org.springframework.util.ReflectionUtils.doWithMethods(bean.getClass(), new org.springframework.util.ReflectionUtils.MethodCallback() {
177 @SuppressWarnings("unchecked")
178 public void doWith(Method method) throws IllegalArgumentException, IllegalAccessException {
179 /*
180 * TODO support callbacks? if
181 * (method.getAnnotation(Callback.class) != null) { try {
182 * Expression e = ExpressionFactory.createExpression(
183 * method.getAnnotation(Callback.class).condition());
184 * JexlContext jc = JexlHelper.createContext();
185 * jc.getVars().put("this", obj); Object r = e.evaluate(jc); if
186 * (!(r instanceof Boolean)) { throw new
187 * RuntimeException("Expression did not returned a boolean value
188 * but: " + r); } Boolean oldVal =
189 * req.getCallbacks().get(method); Boolean newVal = (Boolean) r;
190 * if ((oldVal == null || !oldVal) && newVal) {
191 * req.getCallbacks().put(method, newVal); method.invoke(obj,
192 * new Object[0]); // TODO: handle return value and sent it as
193 * the answer } } catch (Exception e) { throw new
194 * RuntimeException("Unable to invoke callback", e); } }
195 */
196 }
197 });
198 }
199
200 public CamelPostProcessorHelper getPostProcessor() {
201 ObjectHelper.notNull(postProcessor, "postProcessor");
202 return postProcessor;
203 }
204 }