/**

  * Copyright 2010 The Kuali Foundation Licensed under the

  * Educational Community 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.osedu.org/licenses/ECL-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.kuali.rice.ksb.messaging;

 import java.lang.reflect.InvocationHandler;

 import java.lang.reflect.InvocationTargetException;

 import java.lang.reflect.Method;

 import java.lang.reflect.Proxy;

 import javax.xml.namespace.QName;

 import org.apache.log4j.Logger;

 import org.kuali.rice.core.resourceloader.GlobalResourceLoader;

 import org.kuali.rice.core.util.ExceptionUtils;

 /**

  * This class creates a proxy for services deployed on KSB. A 

  * reference to the service is obtained only upon the first method

  * invocation.

  * 

  * @author Kuali Rice Team (rice.collab@kuali.org)

  *

  */

 public class KSBClientProxy implements InvocationHandler {

 private static final Logger LOG = Logger.getLogger(KSBClientProxy.class);

     QName serviceName;

     Object service;

     @SuppressWarnings("unchecked")

     public static <T> T newInstance(String serviceQName, Class<T> interfaceClass) throws InstantiationException, IllegalAccessException {

         return (T)Proxy.newProxyInstance(interfaceClass.getClassLoader(), new Class[] { interfaceClass }, new KSBClientProxy(serviceQName));

     }

     public KSBClientProxy(String serviceQName){

         this.serviceName = QName.valueOf(serviceQName);

     }

     public Object invoke(Object proxy, Method method, Object[] args) throws Throwable {

         if (this.service == null){

             LOG.info("Getting service using GRL for: " + serviceName);

             service = GlobalResourceLoader.getService(serviceName);

             LOG.info("Obtained service using GRL for: " + serviceName);

         }

         try {

             return method.invoke(service, args);

         } catch (InvocationTargetException e) {

             throw ExceptionUtils.unwrapActualCause(e);

         }

     }

 }