001// Copyright 2009-2013 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.services; 016 017import javax.servlet.http.HttpServletRequest; 018 019import org.apache.tapestry5.SymbolConstants; 020import org.apache.tapestry5.internal.TapestryInternalUtils; 021import org.apache.tapestry5.ioc.annotations.Symbol; 022import org.apache.tapestry5.services.ResponseCompressionAnalyzer; 023import org.apache.tapestry5.services.assets.CompressionAnalyzer; 024 025public class ResponseCompressionAnalyzerImpl implements ResponseCompressionAnalyzer 026{ 027 private final HttpServletRequest request; 028 029 private final boolean gzipCompressionEnabled; 030 031 private final CompressionAnalyzer compressionAnalyzer; 032 033 public ResponseCompressionAnalyzerImpl(HttpServletRequest request, 034 @Symbol(SymbolConstants.GZIP_COMPRESSION_ENABLED) 035 boolean gzipCompressionEnabled, CompressionAnalyzer compressionAnalyzer) 036 { 037 this.request = request; 038 this.gzipCompressionEnabled = gzipCompressionEnabled; 039 this.compressionAnalyzer = compressionAnalyzer; 040 } 041 042 public boolean isGZipSupported() 043 { 044 if (!gzipCompressionEnabled) 045 { 046 return false; 047 } 048 049 // TAP5-1880: 050 if (request.getProtocol() == "HTTP/1.0") 051 { 052 return false; 053 } 054 055 String supportedEncodings = request.getHeader("Accept-Encoding"); 056 057 if (supportedEncodings == null) 058 { 059 return false; 060 } 061 062 for (String encoding : TapestryInternalUtils.splitAtCommas(supportedEncodings)) 063 { 064 if (encoding.equalsIgnoreCase("gzip")) 065 { 066 return true; 067 } 068 } 069 070 return false; 071 } 072 073 public boolean isGZipEnabled(String contentType) 074 { 075 return isGZipSupported() && compressionAnalyzer.isCompressable(contentType); 076 } 077}