/*

  * Copyright (c) 2003-2011, Simon Brown

  * All rights reserved.

  *

  * Redistribution and use in source and binary forms, with or without

  * modification, are permitted provided that the following conditions are met:

  *

  *   - Redistributions of source code must retain the above copyright

  *     notice, this list of conditions and the following disclaimer.

  *

  *   - Redistributions in binary form must reproduce the above copyright

  *     notice, this list of conditions and the following disclaimer in

  *     the documentation and/or other materials provided with the

  *     distribution.

  *

  *   - Neither the name of Pebble nor the names of its contributors may

  *     be used to endorse or promote products derived from this software

  *     without specific prior written permission.

  *

  * THIS SOFTWARE IS PROVIDED BY THE COPYRIGHT HOLDERS AND CONTRIBUTORS "AS IS"

  * AND ANY EXPRESS OR IMPLIED WARRANTIES, INCLUDING, BUT NOT LIMITED TO, THE

  * IMPLIED WARRANTIES OF MERCHANTABILITY AND FITNESS FOR A PARTICULAR PURPOSE

  * ARE DISCLAIMED. IN NO EVENT SHALL THE COPYRIGHT OWNER OR CONTRIBUTORS BE

  * LIABLE FOR ANY DIRECT, INDIRECT, INCIDENTAL, SPECIAL, EXEMPLARY, OR

  * CONSEQUENTIAL DAMAGES (INCLUDING, BUT NOT LIMITED TO, PROCUREMENT OF

  * SUBSTITUTE GOODS OR SERVICES; LOSS OF USE, DATA, OR PROFITS; OR BUSINESS

  * INTERRUPTION) HOWEVER CAUSED AND ON ANY THEORY OF LIABILITY, WHETHER IN

  * CONTRACT, STRICT LIABILITY, OR TORT (INCLUDING NEGLIGENCE OR OTHERWISE)

  * ARISING IN ANY WAY OUT OF THE USE OF THIS SOFTWARE, EVEN IF ADVISED OF THE

  * POSSIBILITY OF SUCH DAMAGE.

  */

 package net.sourceforge.pebble.web.filter;

 import java.io.*;

 import java.util.zip.GZIPOutputStream;

 import javax.servlet.*;

 import javax.servlet.http.*;

 public class GZIPResponseStream extends ServletOutputStream {

   protected ByteArrayOutputStream baos = null;

   protected GZIPOutputStream gzipstream = null;

   protected boolean closed = false;

   protected HttpServletResponse response = null;

   protected ServletOutputStream output = null;

   public GZIPResponseStream(HttpServletResponse response) throws IOException {

     closed = false;

     this.response = response;

     this.output = response.getOutputStream();

     baos = new ByteArrayOutputStream();

     gzipstream = new GZIPOutputStream(baos);

   }

   public void close() throws IOException {

     if (closed) {

       throw new IOException("This output stream has already been closed");

     }

     gzipstream.finish();

     gzipstream.flush();

     gzipstream.close();

     byte[] bytes = baos.toByteArray();

     response.setContentLength(bytes.length);

     response.addHeader("Content-Encoding", "gzip");

     output.write(bytes);

     output.flush();

     output.close();

     closed = true;

   }

   public void flush() throws IOException {

     if (closed) {

       throw new IOException("Cannot flush a closed output stream");

     }

     gzipstream.flush();

   }

   public void write(int b) throws IOException {

     if (closed) {

       throw new IOException("Cannot write to a closed output stream");

     }

     gzipstream.write((byte) b);

   }

   public void write(byte b[]) throws IOException {

     write(b, 0, b.length);

   }

   public void write(byte b[], int off, int len) throws IOException {

     if (closed) {

       throw new IOException("Cannot write to a closed output stream");

     }

     gzipstream.write(b, off, len);

   }

 }