/*
* This is part of Geomajas, a GIS framework, http://www.geomajas.org/.
*
* Copyright 2008-2011 Geosparc nv, http://www.geosparc.com/, Belgium.
*
* The program is available in open source according to the GNU Affero
* General Public License. All contributions in this program are covered
* by the Geomajas Contributors License Agreement. For full licensing
* details, see LICENSE.txt in the project root.
*/
package org.geomajas.servlet;
import java.io.ByteArrayOutputStream;
import java.io.IOException;
import java.util.zip.GZIPOutputStream;
import javax.servlet.ServletOutputStream;
import javax.servlet.http.HttpServletResponse;
/**
* Assure resources are GZIP compressed.
*
* @author Jan De Moerloose
*/
public class GzipResponseStream extends ServletOutputStream {
private ByteArrayOutputStream byteStream;
private GZIPOutputStream gzipStream;
private boolean closed;
private HttpServletResponse response;
private ServletOutputStream servletStream;
public GzipResponseStream(HttpServletResponse response) throws IOException {
super();
closed = false;
this.response = response;
this.servletStream = response.getOutputStream();
byteStream = new ByteArrayOutputStream();
gzipStream = new GZIPOutputStream(byteStream);
}
public void close() throws IOException {
if (closed) {
throw new IOException("This output stream has already been closed");
}
gzipStream.finish();
byte[] bytes = byteStream.toByteArray();
response.setContentLength(bytes.length);
response.addHeader("Content-Encoding", "gzip");
servletStream.write(bytes);
servletStream.flush();
servletStream.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);
}
}