// Copyright 2009 The Apache Software Foundation

 //

 // Licensed under the Apache License, Version 2.0 (the "License");

 // you may not use this file except in compliance with the License.

 // You may obtain a copy of the License at

 //

 //     http://www.apache.org/licenses/LICENSE-2.0

 //

 // Unless required by applicable law or agreed to in writing, software

 // distributed under the License is distributed on an "AS IS" BASIS,

 // WITHOUT WARRANTIES OR CONDITIONS OF ANY KIND, either express or implied.

 // See the License for the specific language governing permissions and

 // limitations under the License.

 package org.apache.tapestry5.internal.gzip;

 import org.apache.tapestry5.SymbolConstants;

 import org.apache.tapestry5.ioc.annotations.Symbol;

 import org.apache.tapestry5.services.HttpServletRequestFilter;

 import org.apache.tapestry5.services.HttpServletRequestHandler;

 import org.apache.tapestry5.services.ResponseCompressionAnalyzer;

 import javax.servlet.http.HttpServletRequest;

 import javax.servlet.http.HttpServletResponse;

 import java.io.IOException;

 /**

  * Filter that adds GZIP compression to the response, if the client supports it.

  */

 public class GZipFilter implements HttpServletRequestFilter

 {

     private final int cutover;

     private final ResponseCompressionAnalyzer analyzer;

     public GZipFilter(

             @Symbol(SymbolConstants.MIN_GZIP_SIZE)

             int cutover,

             ResponseCompressionAnalyzer analyzer)

     {

         this.cutover = cutover;

         this.analyzer = analyzer;

     }

     public boolean service(HttpServletRequest request, HttpServletResponse response, HttpServletRequestHandler handler)

             throws IOException

     {

         HttpServletResponse newResponse = analyzer.isGZipSupported()

                                           ? new GZIPEnabledResponse(response, request, cutover, analyzer)

                                           : response;

         return handler.service(request, newResponse);

     }

 }