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.hc.core5.http;
29
30 import java.io.IOException;
31
32 import org.apache.hc.core5.annotation.Contract;
33 import org.apache.hc.core5.annotation.ThreadingBehavior;
34 import org.apache.hc.core5.http.protocol.HttpContext;
35
36 /**
37 * HTTP protocol interceptor is a routine that implements a specific aspect of
38 * the HTTP protocol. Usually protocol interceptors are expected to act upon
39 * one specific header or a group of related headers of the incoming message
40 * or populate the outgoing message with one specific header or a group of
41 * related headers.
42 * <p>
43 * Protocol Interceptors can also manipulate content entities enclosed with messages.
44 * Usually this is accomplished by using the 'Decorator' pattern where a wrapper
45 * entity class is used to decorate the original entity.
46 * <p>
47 * Protocol interceptors must be implemented as thread-safe. Similarly to
48 * servlets, protocol interceptors should not use instance variables unless
49 * access to those variables is synchronized.
50 *
51 * @since 4.0
52 */
53 @Contract(threading = ThreadingBehavior.STATELESS)
54 public interface HttpRequestInterceptor {
55
56 /**
57 * Processes a request.
58 * On the client side, this step is performed before the request is
59 * sent to the server. On the server side, this step is performed
60 * on incoming messages before the message body is evaluated.
61 *
62 * @param request the request to process
63 * @param entity the request entity details or {@code null} if not available
64 * @param context the context for the request
65 *
66 * @throws HttpException in case of an HTTP protocol violation
67 * @throws IOException in case of an I/O error
68 */
69 void process(HttpRequest request, EntityDetails entity, HttpContext context) throws HttpException, IOException;
70
71 }