/*

  * Copyright (C) The Apache Software Foundation. All rights reserved.

  *

  * This software is published under the terms of the Apache Software License

  * version 1.1, a copy of which has been included with this distribution in

  * the LICENSE file.

  * 

  * $Id: MessageletResponseImpl.java 155459 2005-02-26 13:24:44Z dirkv $

  */

 package org.apache.commons.messagelet.impl;

 import java.io.IOException;

 import java.io.PrintWriter;

 import javax.jms.Destination;

 import javax.jms.JMSException;

 import javax.jms.Message;

 import javax.servlet.ServletOutputStream;

 import javax.servlet.ServletResponse;

 import javax.servlet.ServletResponseWrapper;

 import org.apache.commons.messagelet.MessageletResponse;

 import org.apache.commons.messenger.Messenger;

 /** <p><code>MessageletResponseImpl</code> represents a servlet request from

   * a JMS Message source.</p>

   *

   * @author <a href="mailto:jstrachan@apache.org">James Strachan</a>

   * @version $Revision: 155459 $

   */

 public class MessageletResponseImpl extends ServletResponseWrapper implements MessageletResponse {

     /** the messenger used to send replies to */

     private Messenger messenger;

     /** the reply to destination to send replies to */

     private Destination replyToDestination;

     /** The BufferedServletOutputStream that is given to the servlet to capture

      * the response 

      */

     private BufferedServletOutputStream stream = null;

     /** The PrintWriter that has been returned by getWriter(), if any */

     protected PrintWriter writer;

     public MessageletResponseImpl(ServletResponse response) {

         super(response);

     }

     /** Resets the response, ready for a new request */

     public void reset() {

         writer = null;

         stream = null;

     }

     /** Called to finish the request */

     public void finish() throws IOException, JMSException {

         try {

             if ( writer != null ) {

                 writer.flush();

                 writer.close();

             }

             if ( stream != null ) {

                 byte[] data = stream.toByteArray();

                 // for now assume a text message

                 String text = new String(data);

                 Message message = getReplyMessenger().createTextMessage( text );

                 sendReply( message );

             }

         }

         finally {

             writer = null;

             stream = null;

         }

     }

     // MessageletResponse methods

     //-------------------------------------------------------------------------    

     /** Sends a reply to the original message */

     public void sendReply(Message replyMessage) throws JMSException {

         getReplyMessenger().send( getReplyToDestination(), replyMessage );

     }

     public Messenger getReplyMessenger() {

         return messenger;

     }

     public Destination getReplyToDestination() {

         return replyToDestination;

     }

     public void setReplyMessenger(Messenger messenger) {

         this.messenger = messenger;

     }

     public void setReplyToDestination(Destination replyToDestination) {

         this.replyToDestination = replyToDestination;

     }

     // Implementation methods

     //-------------------------------------------------------------------------    

     public void flushBuffer() throws IOException {

         if ( stream != null ) {

             stream.flush();

         }

     }

     public ServletOutputStream getOutputStream() throws IOException {

         if (writer != null) {

             throw new IllegalStateException("getWriter() has already been called " +

             "for this response");

         }

         if (stream == null) {

             stream = createOutputStream();

         }

         return stream;

     }

     public PrintWriter getWriter() throws IOException {

         if (writer != null) {

             return writer;

         }        

         if (stream != null) {

             throw new IllegalStateException("getOutputStream() has already been called for this response");

         }        

         stream = createOutputStream();

         writer = new PrintWriter(stream);

         return writer;

     }

     protected BufferedServletOutputStream createOutputStream() {

         return new BufferedServletOutputStream();

     }

 }