001/* 002 * ==================================================================== 003 * Licensed to the Apache Software Foundation (ASF) under one 004 * or more contributor license agreements. See the NOTICE file 005 * distributed with this work for additional information 006 * regarding copyright ownership. The ASF licenses this file 007 * to you under the Apache License, Version 2.0 (the 008 * "License"); you may not use this file except in compliance 009 * with the License. You may obtain a copy of the License at 010 * 011 * http://www.apache.org/licenses/LICENSE-2.0 012 * 013 * Unless required by applicable law or agreed to in writing, 014 * software distributed under the License is distributed on an 015 * "AS IS" BASIS, WITHOUT WARRANTIES OR CONDITIONS OF ANY 016 * KIND, either express or implied. See the License for the 017 * specific language governing permissions and limitations 018 * under the License. 019 * ==================================================================== 020 * 021 * This software consists of voluntary contributions made by many 022 * individuals on behalf of the Apache Software Foundation. For more 023 * information on the Apache Software Foundation, please see 024 * <http://www.apache.org/>. 025 * 026 */ 027 028package org.apache.http.protocol; 029 030import org.apache.http.HttpException; 031import org.apache.http.HttpRequest; 032import org.apache.http.HttpResponse; 033 034/** 035 * Defines an interface to verify whether an incoming HTTP request meets 036 * the target server's expectations. 037 *<p> 038 * The Expect request-header field is used to indicate that particular 039 * server behaviors are required by the client. 040 *</p> 041 *<pre> 042 * Expect = "Expect" ":" 1#expectation 043 * 044 * expectation = "100-continue" | expectation-extension 045 * expectation-extension = token [ "=" ( token | quoted-string ) 046 * *expect-params ] 047 * expect-params = ";" token [ "=" ( token | quoted-string ) ] 048 *</pre> 049 *<p> 050 * A server that does not understand or is unable to comply with any of 051 * the expectation values in the Expect field of a request MUST respond 052 * with appropriate error status. The server MUST respond with a 417 053 * (Expectation Failed) status if any of the expectations cannot be met 054 * or, if there are other problems with the request, some other 4xx 055 * status. 056 *</p> 057 * 058 * @since 4.0 059 */ 060public interface HttpExpectationVerifier { 061 062 /** 063 * Verifies whether the given request meets the server's expectations. 064 * <p> 065 * If the request fails to meet particular criteria, this method can 066 * trigger a terminal response back to the client by setting the status 067 * code of the response object to a value greater or equal to 068 * {@code 200}. In this case the client will not have to transmit 069 * the request body. If the request meets expectations this method can 070 * terminate without modifying the response object. Per default the status 071 * code of the response object will be set to {@code 100}. 072 * 073 * @param request the HTTP request. 074 * @param response the HTTP response. 075 * @param context the HTTP context. 076 * @throws HttpException in case of an HTTP protocol violation. 077 */ 078 void verify(HttpRequest request, HttpResponse response, HttpContext context) 079 throws HttpException; 080 081}