/*

  * 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.commons.pipeline.stage;

 import java.lang.reflect.InvocationTargetException;

 import java.lang.reflect.Method;

 import org.apache.commons.pipeline.StageException;

 /**

  * Calls a method on the processed object giving it the arguments specified

  * at the time of object construction.

  *

  *

  * @version $Id: InvokeMethodStage.java 3742 2006-08-28 16:50:23Z kjn $

  */

 public class InvokeMethodStage extends BaseStage {

     //private static final Log log = LogFactory.getLog(InvokeMethodStage.class);

     private Method method;

     private Object[] arguments;

     /**

      * Creates a new instance of InvokeMethodStage

      */

     public InvokeMethodStage(Method method){

         this.method = method;

         this.arguments = new Object[] { };

     }

     /**

      * Creates a new instance of InvokeMethodStage

      */

     public InvokeMethodStage(Method method, Object... arguments) {

         this.method = method;

         this.arguments = arguments;

     }

     /**

      * Creates a new instance of InvokeMethodStage from the class and method names.

      */

     public InvokeMethodStage(String className, String methodName, Object... arguments) throws ClassNotFoundException, NoSuchMethodException{

         Class<?> clazz = InvokeMethodStage.class.getClassLoader().loadClass(className);

         Class[] argTypes = new Class[arguments.length];

         for (int i = 0; i < arguments.length; i++) argTypes[i] = arguments[i].getClass();

         this.method = clazz.getMethod(methodName, argTypes);

         this.arguments = arguments;

     }

     /** Returns the method to be accessed by processing

      *@return the method

      */

     public Method getMethod(){

         return this.method;

     }

     /** Returns the objects being used to invoke this method

      *@return The objects being used

      */

     public Object[] getArguments(){

         return this.arguments;

     }

     /** Calls the specified method on the object being processed and exqueues the result

      * @param obj The object being processed.

      */

     public void process(Object obj) throws org.apache.commons.pipeline.StageException {        

         try {

             Object result = method.invoke(obj, arguments);

             this.emit(result);

         } catch (IllegalAccessException e){

             throw new StageException(this, e);

         } catch (InvocationTargetException e){

             throw new StageException(this, e);

         }

     }

 }