/**
* 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.component.bean;
import java.lang.reflect.InvocationHandler;
import java.lang.reflect.InvocationTargetException;
import java.lang.reflect.Method;
import org.apache.camel.Endpoint;
import org.apache.camel.Exchange;
import org.apache.camel.ExchangePattern;
import org.apache.camel.Producer;
import org.apache.camel.RuntimeCamelException;
import org.apache.camel.impl.DefaultExchange;
import org.apache.commons.logging.Log;
import org.apache.commons.logging.LogFactory;
/**
* An {@link java.lang.reflect.InvocationHandler} which invokes a
* message exchange on a camel {@link Endpoint}
*
* @version $Revision: 889160 $
*/
public class CamelInvocationHandler implements InvocationHandler {
private static final transient Log LOG = LogFactory.getLog(CamelInvocationHandler.class);
private final Endpoint endpoint;
private final Producer producer;
private final MethodInfoCache methodInfoCache;
public CamelInvocationHandler(Endpoint endpoint, Producer producer, MethodInfoCache methodInfoCache) {
this.endpoint = endpoint;
this.producer = producer;
this.methodInfoCache = methodInfoCache;
}
public Object invoke(Object proxy, Method method, Object[] args) throws Throwable {
BeanInvocation invocation = new BeanInvocation(method, args);
ExchangePattern pattern = ExchangePattern.InOut;
MethodInfo methodInfo = methodInfoCache.getMethodInfo(method);
if (methodInfo != null) {
pattern = methodInfo.getPattern();
}
Exchange exchange = new DefaultExchange(endpoint, pattern);
exchange.getIn().setBody(invocation);
// process the exchange
if (LOG.isTraceEnabled()) {
LOG.trace("Proxied method call " + method.getName() + " invoking producer: " + producer);
}
producer.process(exchange);
// check if we had an exception
Throwable fault = exchange.getException();
if (fault != null) {
if (fault instanceof RuntimeCamelException) {
// if the inner cause is a runtime exception we can throw it directly
if (fault.getCause() instanceof RuntimeException) {
throw (RuntimeException) ((RuntimeCamelException) fault).getCause();
}
throw (RuntimeCamelException) fault;
}
throw new InvocationTargetException(fault);
}
// do not return a reply if the method is VOID or the MEP is not OUT capable
Class<?> to = method.getReturnType();
if (to == Void.TYPE || !pattern.isOutCapable()) {
return null;
}
// only convert if there is a body
if (!exchange.hasOut() || exchange.getOut().getBody() == null) {
// there is no body so return null
return null;
}
// use type converter so we can convert output in the desired type defined by the method
// and let it be mandatory so we know wont return null if we cant convert it to the defined type
Object answer = exchange.getOut().getMandatoryBody(to);
if (LOG.isTraceEnabled()) {
LOG.trace("Proxied method call " + method.getName() + " returning: " + answer);
}
return answer;
}
}