/*

  * $Source: /usr/cvsroot/melati/melati/src/main/java/org/melati/template/velocity/MelatiVelocityWriter.java,v $

  * $Revision: 1.3 $

  *

  * Copyright (C) 2000 Tim Joyce

  *

  * Part of Melati (http://melati.org), a framework for the rapid

  * development of clean, maintainable web applications.

  *

  * Melati is free software; Permission is granted to copy, distribute

  * and/or modify this software under the terms either:

  *

  * a) the GNU General Public License as published by the Free Software

  *    Foundation; either version 2 of the License, or (at your option)

  *    any later version,

  *

  *    or

  *

  * b) any version of the Melati Software License, as published

  *    at http://melati.org

  *

  * You should have received a copy of the GNU General Public License and

  * the Melati Software License along with this program;

  * if not, write to the Free Software Foundation, Inc.,

  * 59 Temple Place, Suite 330, Boston, MA 02111-1307 USA to obtain the

  * GNU General Public License and visit http://melati.org to obtain the

  * Melati Software License.

  *

  * Feel free to contact the Developers of Melati (http://melati.org),

  * if you would like to work out a different arrangement than the options

  * outlined here.  It is our intention to allow Melati to be used by as

  * wide an audience as possible.

  *

  * This program is distributed in the hope that it will be useful,

  * but WITHOUT ANY WARRANTY; without even the implied warranty of

  * MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE.  See the

  * GNU General Public License for more details.

  *

  * Contact details for copyright holder:

  *

  *     Tim Joyce <timj At paneris.org>

  */

 package org.melati.template.velocity;

 import java.io.OutputStream;

 import java.io.OutputStreamWriter;

 import java.io.IOException;

 import javax.servlet.http.HttpServletResponse;

 import org.melati.util.MelatiWriter;

 import org.apache.velocity.io.VelocityWriter;

 import org.apache.velocity.util.SimplePool;

 /**

  * This provides an interface for objects that output from melati.

  */

 public class MelatiVelocityWriter extends MelatiWriter {

   private static SimplePool writerPool = new SimplePool(40);

   protected OutputStream outputStream;

   /**

    * Constructor.

    * @param response the response to write to

    * @throws IOException if getOutputStream throws one

    */

   public MelatiVelocityWriter(HttpServletResponse response)

       throws IOException {

     this(response.getOutputStream(), response.getCharacterEncoding());

   }

   /**

    * Constructor.

    * @param output OutputStream to write to

    * @param encoding character encoding to use

    * @throws IOException if getOutputStream throws one

    */

   public MelatiVelocityWriter(OutputStream output, String encoding)

       throws IOException {

     // need to make this accessable to subcalsses

     outputStream = output;

     out = (VelocityWriter)writerPool.get();

     if (out == null) {

       out = new VelocityWriter(new OutputStreamWriter(output, encoding),

                                4 * 1024, true);

     } else {

       ((VelocityWriter)out).recycle(new OutputStreamWriter(output, encoding));

     }

   }

   /**

    * As we can write to the underlying peer the Flusher may not 

    * get started so we should start it here.

    * @return the underlying output

    */

   public VelocityWriter getPeer() {

     startFlushing();

     return (VelocityWriter)out;

   }

   /**

    * {@inheritDoc}

    * @see java.io.Closeable#close()

    */

   public void close()

       throws IOException {

     super.close();

     writerPool.put(getPeer());

   }

 }