1   /*
    2    * $HeadURL: https://svn.apache.org/repos/asf/httpcomponents/httpcore/tags/4.0.1/httpcore/src/main/java/org/apache/http/HttpResponseInterceptor.java $
    3    * $Revision: 744522 $
    4    * $Date: 2009-02-14 17:56:03 +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;
   33   
   34   import java.io.IOException;
   35   
   36   import org.apache.http.protocol.HttpContext;
   37   
   38   /**
   39    * HTTP protocol interceptor is a routine that implements a specific aspect of 
   40    * the HTTP protocol. Usually protocol interceptors are expected to act upon 
   41    * one specific header or a group of related headers of the incoming message 
   42    * or populate the outgoing message with one specific header or a group of 
   43    * related headers. Protocol 
   44    * <p>
   45    * Interceptors can also manipulate content entities enclosed with messages.
   46    * Usually this is accomplished by using the 'Decorator' pattern where a wrapper 
   47    * entity class is used to decorate the original entity. 
   48    * <p>
   49    * Protocol interceptors must be implemented as thread-safe. Similarly to 
   50    * servlets, protocol interceptors should not use instance variables unless 
   51    * access to those variables is synchronized.
   52    *
   53    *
   54    * <!-- empty lines above to avoid 'svn diff' context problems -->
   55    * @version $Revision: 744522 $
   56    * 
   57    * @since 4.0
   58    */
   59   public interface HttpResponseInterceptor {
   60   
   61       /**
   62        * Processes a response.
   63        * On the server side, this step is performed before the response is
   64        * sent to the client. On the client side, this step is performed
   65        * on incoming messages before the message body is evaluated.
   66        *
   67        * @param response  the response to postprocess
   68        * @param context   the context for the request
   69        *
   70        * @throws HttpException in case of an HTTP protocol violation
   71        * @throws IOException in case of an I/O error
   72        */
   73       void process(HttpResponse response, HttpContext context) 
   74           throws HttpException, IOException;
   75   
   76   }