/**
* Licensed to the Apache Software Foundation (ASF) under one or more
* contributor license agreements. See the NOTICE file distributed with
* this work for additional information regarding copyright ownership.
* The ASF licenses this file to You under the Apache License, Version 2.0
* (the "License"); you may not use this file except in compliance with
* the License. You may obtain a copy of the License at
*
* http://www.apache.org/licenses/LICENSE-2.0
*
* Unless required by applicable law or agreed to in writing, software
* distributed under the License is distributed on an "AS IS" BASIS,
* WITHOUT WARRANTIES OR CONDITIONS OF ANY KIND, either express or implied.
* See the License for the specific language governing permissions and
* limitations under the License.
*/
package org.apache.camel.spring;
import java.lang.reflect.Field;
import java.lang.reflect.Method;
import javax.xml.bind.annotation.XmlAccessType;
import javax.xml.bind.annotation.XmlAccessorType;
import javax.xml.bind.annotation.XmlRootElement;
import javax.xml.bind.annotation.XmlTransient;
import org.apache.camel.CamelContextAware;
import org.apache.camel.CamelTemplate;
import org.apache.camel.Consumer;
import org.apache.camel.Endpoint;
import org.apache.camel.EndpointInject;
import org.apache.camel.MessageDriven;
import org.apache.camel.PollingConsumer;
import org.apache.camel.Processor;
import org.apache.camel.Producer;
import org.apache.camel.RuntimeCamelException;
import org.apache.camel.Service;
import org.apache.camel.component.bean.BeanProcessor;
import org.apache.camel.spring.util.ReflectionUtils;
import org.apache.camel.util.ObjectHelper;
import org.apache.commons.logging.Log;
import org.apache.commons.logging.LogFactory;
import org.springframework.beans.BeansException;
import org.springframework.beans.factory.NoSuchBeanDefinitionException;
import org.springframework.beans.factory.config.BeanPostProcessor;
import org.springframework.context.ApplicationContext;
import org.springframework.context.ApplicationContextAware;
import static org.apache.camel.util.ObjectHelper.isNotNullAndNonEmpty;
import static org.apache.camel.util.ObjectHelper.isNullOrBlank;
/**
* A post processor to perform injection of {@link Endpoint} and
* {@link Producer} instances together with binding methods annotated with
* {@link MessageDriven @MessageDriven} to a Camel consumer.
*
* @version $Revision: 642782 $
*/
@XmlRootElement(name = "beanPostProcessor")
@XmlAccessorType(XmlAccessType.FIELD)
public class CamelBeanPostProcessor implements BeanPostProcessor, ApplicationContextAware {
private static final transient Log LOG = LogFactory.getLog(CamelBeanPostProcessor.class);
@XmlTransient
private SpringCamelContext camelContext;
@XmlTransient
private ApplicationContext applicationContext;
public CamelBeanPostProcessor() {
}
public Object postProcessBeforeInitialization(Object bean, String beanName) throws BeansException {
injectFields(bean);
injectMethods(bean);
if (bean instanceof CamelContextAware) {
CamelContextAware contextAware = (CamelContextAware)bean;
if (camelContext == null) {
LOG.warn("No CamelContext defined yet so cannot inject into: " + bean);
} else {
contextAware.setCamelContext(camelContext);
}
}
return bean;
}
public Object postProcessAfterInitialization(Object bean, String beanName) throws BeansException {
return bean;
}
// Properties
// -------------------------------------------------------------------------
public void setApplicationContext(ApplicationContext applicationContext) throws BeansException {
this.applicationContext = applicationContext;
}
public SpringCamelContext getCamelContext() {
return camelContext;
}
public void setCamelContext(SpringCamelContext camelContext) {
this.camelContext = camelContext;
}
// Implementation methods
// -------------------------------------------------------------------------
/**
* A strategy method to allow implementations to perform some custom JBI
* based injection of the POJO
*
* @param bean the bean to be injected
*/
protected void injectFields(final Object bean) {
ReflectionUtils.doWithFields(bean.getClass(), new ReflectionUtils.FieldCallback() {
public void doWith(Field field) throws IllegalArgumentException, IllegalAccessException {
EndpointInject annotation = field.getAnnotation(EndpointInject.class);
if (annotation != null) {
ReflectionUtils.setField(field, bean, getEndpointInjectionValue(annotation, field.getType(), field.getName()));
}
}
});
}
protected void injectMethods(final Object bean) {
ReflectionUtils.doWithMethods(bean.getClass(), new ReflectionUtils.MethodCallback() {
@SuppressWarnings("unchecked")
public void doWith(Method method) throws IllegalArgumentException, IllegalAccessException {
setterInjection(method, bean);
consumerInjection(method, bean);
}
});
}
protected void setterInjection(Method method, Object bean) {
EndpointInject annoation = method.getAnnotation(EndpointInject.class);
if (annoation != null) {
Class<?>[] parameterTypes = method.getParameterTypes();
if (parameterTypes != null) {
if (parameterTypes.length != 1) {
LOG.warn("Ignoring badly annotated method for injection due to incorrect number of parameters: " + method);
} else {
String propertyName = ObjectHelper.getPropertyName(method);
Object value = getEndpointInjectionValue(annoation, parameterTypes[0], propertyName);
ObjectHelper.invokeMethod(method, bean, value);
}
}
}
}
protected void consumerInjection(final Object bean) {
ReflectionUtils.doWithMethods(bean.getClass(), new ReflectionUtils.MethodCallback() {
@SuppressWarnings("unchecked")
public void doWith(Method method) throws IllegalArgumentException, IllegalAccessException {
/*
* TODO support callbacks? if
* (method.getAnnotation(Callback.class) != null) { try {
* Expression e = ExpressionFactory.createExpression(
* method.getAnnotation(Callback.class).condition());
* JexlContext jc = JexlHelper.createContext();
* jc.getVars().put("this", obj); Object r = e.evaluate(jc); if
* (!(r instanceof Boolean)) { throw new
* RuntimeException("Expression did not returned a boolean value
* but: " + r); } Boolean oldVal =
* req.getCallbacks().get(method); Boolean newVal = (Boolean) r;
* if ((oldVal == null || !oldVal) && newVal) {
* req.getCallbacks().put(method, newVal); method.invoke(obj,
* new Object[0]); // TODO: handle return value and sent it as
* the answer } } catch (Exception e) { throw new
* RuntimeException("Unable to invoke callback", e); } }
*/
}
});
}
protected void consumerInjection(Method method, Object bean) {
MessageDriven annotation = method.getAnnotation(MessageDriven.class);
if (annotation != null) {
LOG.info("Creating a consumer for: " + annotation);
// lets bind this method to a listener
String injectionPointName = method.getName();
Endpoint endpoint = getEndpointInjection(annotation.uri(), annotation.name(), injectionPointName);
if (endpoint != null) {
try {
Processor processor = createConsumerProcessor(bean, method, endpoint);
LOG.info("Created processor: " + processor);
Consumer consumer = endpoint.createConsumer(processor);
startService(consumer);
} catch (Exception e) {
LOG.warn(e);
throw new RuntimeCamelException(e);
}
}
}
}
protected void startService(Service service) throws Exception {
camelContext.addService(service);
}
/**
* Create a processor which invokes the given method when an incoming
* message exchange is received
*/
protected Processor createConsumerProcessor(final Object pojo, final Method method, final Endpoint endpoint) {
BeanProcessor answer = new BeanProcessor(pojo, getCamelContext());
answer.setMethodObject(method);
return answer;
}
/**
* Creates the value for the injection point for the given annotation
*/
protected Object getEndpointInjectionValue(EndpointInject annotation, Class<?> type, String injectionPointName) {
Endpoint endpoint = getEndpointInjection(annotation.uri(), annotation.name(), injectionPointName);
if (endpoint != null) {
if (type.isInstance(endpoint)) {
return endpoint;
} else if (type.isAssignableFrom(Producer.class)) {
return createInjectionProducer(endpoint);
} else if (type.isAssignableFrom(CamelTemplate.class)) {
return new CamelTemplate(getCamelContext(), endpoint);
} else if (type.isAssignableFrom(PollingConsumer.class)) {
return createInjectionPollingConsumer(endpoint);
} else {
throw new IllegalArgumentException("Invalid type: " + type.getName() + " which cannot be injected via @EndpointInject for " + endpoint);
}
}
return null;
}
/**
* Factory method to create a started {@link PollingConsumer} to be injected
* into a POJO
*/
protected PollingConsumer createInjectionPollingConsumer(Endpoint endpoint) {
try {
PollingConsumer pollingConsumer = endpoint.createPollingConsumer();
startService(pollingConsumer);
return pollingConsumer;
} catch (Exception e) {
throw new RuntimeCamelException(e);
}
}
/**
* A Factory method to create a started {@link Producer} to be injected into
* a POJO
*/
protected Producer createInjectionProducer(Endpoint endpoint) {
try {
Producer producer = endpoint.createProducer();
startService(producer);
return producer;
} catch (Exception e) {
throw new RuntimeCamelException(e);
}
}
protected Endpoint getEndpointInjection(String uri, String name, String injectionPointName) {
Endpoint endpoint = null;
if (isNotNullAndNonEmpty(uri)) {
endpoint = camelContext.getEndpoint(uri);
} else {
if (isNullOrBlank(name)) {
name = injectionPointName;
}
endpoint = (Endpoint) applicationContext.getBean(name);
if (endpoint == null) {
throw new NoSuchBeanDefinitionException(name);
}
}
return endpoint;
}
}