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1   /*
2    * ====================================================================
3    * Licensed to the Apache Software Foundation (ASF) under one
4    * or more contributor license agreements.  See the NOTICE file
5    * distributed with this work for additional information
6    * regarding copyright ownership.  The ASF licenses this file
7    * to you under the Apache License, Version 2.0 (the
8    * "License"); you may not use this file except in compliance
9    * with the License.  You may obtain a copy of the License at
10   *
11   *   http://www.apache.org/licenses/LICENSE-2.0
12   *
13   * Unless required by applicable law or agreed to in writing,
14   * software distributed under the License is distributed on an
15   * "AS IS" BASIS, WITHOUT WARRANTIES OR CONDITIONS OF ANY
16   * KIND, either express or implied.  See the License for the
17   * specific language governing permissions and limitations
18   * under the License.
19   * ====================================================================
20   *
21   * This software consists of voluntary contributions made by many
22   * individuals on behalf of the Apache Software Foundation.  For more
23   * information on the Apache Software Foundation, please see
24   * <http://www.apache.org/>.
25   *
26   */
27  
28  package org.apache.http;
29  
30  import java.io.IOException;
31  
32  import org.apache.http.protocol.HttpContext;
33  
34  /**
35   * HTTP protocol interceptor is a routine that implements a specific aspect of
36   * the HTTP protocol. Usually protocol interceptors are expected to act upon
37   * one specific header or a group of related headers of the incoming message
38   * or populate the outgoing message with one specific header or a group of
39   * related headers. Protocol
40   * <p>
41   * Interceptors can also manipulate content entities enclosed with messages.
42   * Usually this is accomplished by using the 'Decorator' pattern where a wrapper
43   * entity class is used to decorate the original entity.
44   * <p>
45   * Protocol interceptors must be implemented as thread-safe. Similarly to
46   * servlets, protocol interceptors should not use instance variables unless
47   * access to those variables is synchronized.
48   *
49   * @since 4.0
50   */
51  public interface HttpResponseInterceptor {
52  
53      /**
54       * Processes a response.
55       * On the server side, this step is performed before the response is
56       * sent to the client. On the client side, this step is performed
57       * on incoming messages before the message body is evaluated.
58       *
59       * @param response  the response to postprocess
60       * @param context   the context for the request
61       *
62       * @throws HttpException in case of an HTTP protocol violation
63       * @throws IOException in case of an I/O error
64       */
65      void process(HttpResponse response, HttpContext context)
66          throws HttpException, IOException;
67  
68  }