001// Copyright 2009 The Apache Software Foundation 002// 003// Licensed under the Apache License, Version 2.0 (the "License"); 004// you may not use this file except in compliance with the License. 005// You may obtain a copy of the License at 006// 007// http://www.apache.org/licenses/LICENSE-2.0 008// 009// Unless required by applicable law or agreed to in writing, software 010// distributed under the License is distributed on an "AS IS" BASIS, 011// WITHOUT WARRANTIES OR CONDITIONS OF ANY KIND, either express or implied. 012// See the License for the specific language governing permissions and 013// limitations under the License. 014 015package org.apache.tapestry5.internal.gzip; 016 017import org.apache.tapestry5.SymbolConstants; 018import org.apache.tapestry5.ioc.annotations.Symbol; 019import org.apache.tapestry5.services.HttpServletRequestFilter; 020import org.apache.tapestry5.services.HttpServletRequestHandler; 021import org.apache.tapestry5.services.ResponseCompressionAnalyzer; 022 023import javax.servlet.http.HttpServletRequest; 024import javax.servlet.http.HttpServletResponse; 025import java.io.IOException; 026 027/** 028 * Filter that adds GZIP compression to the response, if the client supports it. 029 */ 030public class GZipFilter implements HttpServletRequestFilter 031{ 032 private final int cutover; 033 034 private final ResponseCompressionAnalyzer analyzer; 035 036 public GZipFilter( 037 @Symbol(SymbolConstants.MIN_GZIP_SIZE) 038 int cutover, 039 040 ResponseCompressionAnalyzer analyzer) 041 { 042 this.cutover = cutover; 043 this.analyzer = analyzer; 044 } 045 046 public boolean service(HttpServletRequest request, HttpServletResponse response, HttpServletRequestHandler handler) 047 throws IOException 048 { 049 HttpServletResponse newResponse = analyzer.isGZipSupported() 050 ? new GZIPEnabledResponse(response, request, cutover, analyzer) 051 : response; 052 053 return handler.service(request, newResponse); 054 } 055}