1   /*
    2    * $HeadURL: https://svn.apache.org/repos/asf/httpcomponents/httpcore/tags/4.0.1/httpcore/src/main/java/org/apache/http/protocol/ResponseConnControl.java $
    3    * $Revision: 744532 $
    4    * $Date: 2009-02-14 18:12:18 +0100 (Sat, 14 Feb 2009) $
    5    *
    6    * ====================================================================
    7    * Licensed to the Apache Software Foundation (ASF) under one
    8    * or more contributor license agreements.  See the NOTICE file
    9    * distributed with this work for additional information
   10    * regarding copyright ownership.  The ASF licenses this file
   11    * to you under the Apache License, Version 2.0 (the
   12    * "License"); you may not use this file except in compliance
   13    * with the License.  You may obtain a copy of the License at
   14    *
   15    *   http://www.apache.org/licenses/LICENSE-2.0
   16    *
   17    * Unless required by applicable law or agreed to in writing,
   18    * software distributed under the License is distributed on an
   19    * "AS IS" BASIS, WITHOUT WARRANTIES OR CONDITIONS OF ANY
   20    * KIND, either express or implied.  See the License for the
   21    * specific language governing permissions and limitations
   22    * under the License.
   23    * ====================================================================
   24    *
   25    * This software consists of voluntary contributions made by many
   26    * individuals on behalf of the Apache Software Foundation.  For more
   27    * information on the Apache Software Foundation, please see
   28    * <http://www.apache.org/>.
   29    *
   30    */
   31   
   32   package org.apache.http.protocol;
   33   
   34   import java.io.IOException;
   35   
   36   import org.apache.http.Header;
   37   import org.apache.http.HttpEntity;
   38   import org.apache.http.HttpException;
   39   import org.apache.http.HttpRequest;
   40   import org.apache.http.HttpResponse;
   41   import org.apache.http.HttpResponseInterceptor;
   42   import org.apache.http.HttpStatus;
   43   import org.apache.http.HttpVersion;
   44   import org.apache.http.ProtocolVersion;
   45   
   46   /**
   47    * ResponseConnControl is responsible for adding <code>Connection</code> header 
   48    * to the outgoing responses, which is essential for managing persistence of 
   49    * <code>HTTP/1.0</code> connections. This interceptor is recommended for 
   50    * server side protocol processors.
   51    *
   52    *
   53    * @version $Revision: 744532 $
   54    * 
   55    * @since 4.0
   56    */
   57   public class ResponseConnControl implements HttpResponseInterceptor {
   58   
   59       public ResponseConnControl() {
   60           super();
   61       }
   62       
   63       public void process(final HttpResponse response, final HttpContext context) 
   64               throws HttpException, IOException {
   65           if (response == null) {
   66               throw new IllegalArgumentException("HTTP response may not be null");
   67           }
   68           if (context == null) {
   69               throw new IllegalArgumentException("HTTP context may not be null");
   70           }
   71           // Always drop connection after certain type of responses
   72           int status = response.getStatusLine().getStatusCode();
   73           if (status == HttpStatus.SC_BAD_REQUEST ||
   74                   status == HttpStatus.SC_REQUEST_TIMEOUT ||
   75                   status == HttpStatus.SC_LENGTH_REQUIRED ||
   76                   status == HttpStatus.SC_REQUEST_TOO_LONG ||
   77                   status == HttpStatus.SC_REQUEST_URI_TOO_LONG ||
   78                   status == HttpStatus.SC_SERVICE_UNAVAILABLE ||
   79                   status == HttpStatus.SC_NOT_IMPLEMENTED) {
   80               response.setHeader(HTTP.CONN_DIRECTIVE, HTTP.CONN_CLOSE);
   81               return;
   82           }
   83           // Always drop connection for HTTP/1.0 responses and below
   84           // if the content body cannot be correctly delimited
   85           HttpEntity entity = response.getEntity();
   86           if (entity != null) {
   87               ProtocolVersion ver = response.getStatusLine().getProtocolVersion();
   88               if (entity.getContentLength() < 0 && 
   89                       (!entity.isChunked() || ver.lessEquals(HttpVersion.HTTP_1_0))) {
   90                   response.setHeader(HTTP.CONN_DIRECTIVE, HTTP.CONN_CLOSE);
   91                   return;
   92               }
   93           }
   94           // Drop connection if requested by the client
   95           HttpRequest request = (HttpRequest)
   96               context.getAttribute(ExecutionContext.HTTP_REQUEST);
   97           if (request != null) {
   98               Header header = request.getFirstHeader(HTTP.CONN_DIRECTIVE);
   99               if (header != null) {
  100                   response.setHeader(HTTP.CONN_DIRECTIVE, header.getValue());
  101               }
  102           }
  103       }
  104       
  105   }