001// Copyright 2009, 2012 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; 022import org.apache.tapestry5.services.assets.CompressionAnalyzer; 023 024import javax.servlet.http.HttpServletRequest; 025import javax.servlet.http.HttpServletResponse; 026import java.io.IOException; 027 028/** 029 * Filter that adds GZIP compression to the response, if the client supports it. 030 */ 031public class GZipFilter implements HttpServletRequestFilter 032{ 033 private final int cutover; 034 035 private final ResponseCompressionAnalyzer responseAnalyzer; 036 037 private final CompressionAnalyzer compressionAnalyzer; 038 039 public GZipFilter( 040 @Symbol(SymbolConstants.MIN_GZIP_SIZE) 041 int cutover, 042 043 ResponseCompressionAnalyzer responseAnalyzer, 044 045 CompressionAnalyzer compressionAnalyzer) 046 { 047 this.cutover = cutover; 048 this.responseAnalyzer = responseAnalyzer; 049 this.compressionAnalyzer = compressionAnalyzer; 050 } 051 052 public boolean service(HttpServletRequest request, HttpServletResponse response, HttpServletRequestHandler handler) 053 throws IOException 054 { 055 HttpServletResponse newResponse = responseAnalyzer.isGZipSupported() 056 ? new GZIPEnabledResponse(response, request, cutover, compressionAnalyzer) 057 : response; 058 059 return handler.service(request, newResponse); 060 } 061}