1   /*
    2    * $HeadURL: https://svn.apache.org/repos/asf/httpcomponents/httpcore/tags/4.0.1/httpcore/src/main/java/org/apache/http/protocol/ResponseServer.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.HttpException;
   37   import org.apache.http.HttpResponse;
   38   import org.apache.http.HttpResponseInterceptor;
   39   import org.apache.http.params.CoreProtocolPNames;
   40   
   41   /**
   42    * ResponseServer is responsible for adding <code>Server</code> header. This 
   43    * interceptor is recommended for server side protocol processors. 
   44    *
   45    *
   46    * @version $Revision: 744532 $
   47    * 
   48    * @since 4.0
   49    */
   50   public class ResponseServer implements HttpResponseInterceptor {
   51   
   52       public ResponseServer() {
   53           super();
   54       }
   55   
   56       public void process(final HttpResponse response, final HttpContext context) 
   57               throws HttpException, IOException {
   58           if (response == null) {
   59               throw new IllegalArgumentException("HTTP request may not be null");
   60           }
   61           if (!response.containsHeader(HTTP.SERVER_HEADER)) {
   62               String s = (String) response.getParams().getParameter(
   63                       CoreProtocolPNames.ORIGIN_SERVER);
   64               if (s != null) {
   65                   response.addHeader(HTTP.SERVER_HEADER, s);
   66               }
   67           }
   68       }
   69       
   70   }