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 }