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.protocol;
29
30 import org.apache.http.HttpException;
31 import org.apache.http.HttpRequest;
32 import org.apache.http.HttpResponse;
33
34 /**
35 * Defines an interface to verify whether an incoming HTTP request meets
36 * the target server's expectations.
37 *<p>
38 * The Expect request-header field is used to indicate that particular
39 * server behaviors are required by the client.
40 *</p>
41 *<pre>
42 * Expect = "Expect" ":" 1#expectation
43 *
44 * expectation = "100-continue" | expectation-extension
45 * expectation-extension = token [ "=" ( token | quoted-string )
46 * *expect-params ]
47 * expect-params = ";" token [ "=" ( token | quoted-string ) ]
48 *</pre>
49 *<p>
50 * A server that does not understand or is unable to comply with any of
51 * the expectation values in the Expect field of a request MUST respond
52 * with appropriate error status. The server MUST respond with a 417
53 * (Expectation Failed) status if any of the expectations cannot be met
54 * or, if there are other problems with the request, some other 4xx
55 * status.
56 *</p>
57 *
58 * @since 4.0
59 */
60 public interface HttpExpectationVerifier {
61
62 /**
63 * Verifies whether the given request meets the server's expectations.
64 * <p>
65 * If the request fails to meet particular criteria, this method can
66 * trigger a terminal response back to the client by setting the status
67 * code of the response object to a value greater or equal to
68 * {@code 200}. In this case the client will not have to transmit
69 * the request body. If the request meets expectations this method can
70 * terminate without modifying the response object. Per default the status
71 * code of the response object will be set to {@code 100}.
72 *
73 * @param request the HTTP request.
74 * @param response the HTTP response.
75 * @param context the HTTP context.
76 * @throws HttpException in case of an HTTP protocol violation.
77 */
78 void verify(HttpRequest request, HttpResponse response, HttpContext context)
79 throws HttpException;
80
81 }