001 //$HeadURL: https://svn.wald.intevation.org/svn/deegree/base/branches/2.3_testing/src/org/deegree/enterprise/servlet/GZIPFilter.java $
002 /*----------------------------------------------------------------------------
003 This file originated as work from Jayson Falkner.
004
005 Copyright 2003 Jayson Falkner (jayson@jspinsider.com)
006 This code is from "Servlets and JavaServer pages; the J2EE Web Tier",
007 http://www.jspbook.com. You may freely use the code both commercially
008 and non-commercially. If you like the code, please pick up a copy of
009 the book and help support the authors, development of more free code,
010 and the JSP/Servlet/J2EE community.
011 ----------------------------------------------------------------------------*/
012 package org.deegree.enterprise.servlet;
013
014 import java.io.IOException;
015
016 import javax.servlet.Filter;
017 import javax.servlet.FilterChain;
018 import javax.servlet.FilterConfig;
019 import javax.servlet.ServletException;
020 import javax.servlet.ServletRequest;
021 import javax.servlet.ServletResponse;
022 import javax.servlet.http.HttpServletRequest;
023 import javax.servlet.http.HttpServletResponse;
024
025 import org.deegree.framework.log.ILogger;
026 import org.deegree.framework.log.LoggerFactory;
027
028 /**
029 * ServletFilter that enables compression of response content, if the client supports GZIP compression
030 * (accept-encoding=gzip ...).
031 *
032 * @author <a href="mailto:jayson@jspinsider.com">Jayson Falkner</a>
033 * @author last edited by: $Author: mschneider $
034 *
035 * @version $Revision: 20326 $, $Date: 2009-10-22 18:41:56 +0200 (Do, 22. Okt 2009) $
036 */
037 public class GZIPFilter implements Filter {
038
039 private static final ILogger LOG = LoggerFactory.getLogger( GZIPFilter.class );
040
041 /**
042 * @param req
043 * @param res
044 * @param chain
045 * @throws IOException
046 * @throws ServletException
047 */
048 public void doFilter( ServletRequest req, ServletResponse res, FilterChain chain )
049 throws IOException, ServletException {
050 if ( req instanceof HttpServletRequest ) {
051 HttpServletRequest request = (HttpServletRequest) req;
052 HttpServletResponse response = (HttpServletResponse) res;
053 String ae = request.getHeader( "accept-encoding" );
054 if ( ae != null && ae.indexOf( "gzip" ) != -1 ) {
055 LOG.logDebug( "GZIP supported, compressing." );
056 GZIPResponseWrapper wrappedResponse = new GZIPResponseWrapper( response );
057 chain.doFilter( req, wrappedResponse );
058 wrappedResponse.finishResponse();
059 return;
060 }
061 chain.doFilter( req, res );
062 }
063 }
064
065 /**
066 * @param filterConfig
067 */
068 public void init( FilterConfig filterConfig ) {
069 // noop
070 }
071
072 /**
073 *
074 */
075 public void destroy() {
076 // noop
077 }
078 }