http://hc.apache.org/httpcomponents-core-ga: Apache HttpComponents Core (blocking I/O) (The Apache Software Foundation)
  • Julius Davies
  • Andrea Selva
  • Steffen Pingel
  • Quintin Beukes
  • Marc Beyerle
  • James Abley
  • Michajlo Matijkiw 
/*
 * ====================================================================
 * Licensed to the Apache Software Foundation (ASF) under one
 * or more contributor license agreements.  See the NOTICE file
 * distributed with this work for additional information
 * regarding copyright ownership.  The ASF licenses this file
 * to you under the Apache License, Version 2.0 (the
 * "License"); you may not use this file except in compliance
 * with the License.  You may obtain a copy of the License at
 *
 *   http://www.apache.org/licenses/LICENSE-2.0
 *
 * Unless required by applicable law or agreed to in writing,
 * software distributed under the License is distributed on an
 * "AS IS" BASIS, WITHOUT WARRANTIES OR CONDITIONS OF ANY
 * KIND, either express or implied.  See the License for the
 * specific language governing permissions and limitations
 * under the License.
 * ====================================================================
 *
 * This software consists of voluntary contributions made by many
 * individuals on behalf of the Apache Software Foundation.  For more
 * information on the Apache Software Foundation, please see
 * <http://www.apache.org/>.
 *
 */

package org.apache.http.protocol;

import org.apache.http.HttpException;
import org.apache.http.HttpRequest;
import org.apache.http.HttpResponse;


Defines an interface to verify whether an incoming HTTP request meets
the target server's expectations.


The Expect request-header field is used to indicate that particular
server behaviors are required by the client.



   Expect       =  "Expect" ":" 1#expectation
   expectation  =  "100-continue" | expectation-extension
   expectation-extension =  token [ "=" ( token | quoted-string )
                            *expect-params ]
   expect-params =  ";" token [ "=" ( token | quoted-string ) ]




A server that does not understand or is unable to comply with any of
the expectation values in the Expect field of a request MUST respond
with appropriate error status. The server MUST respond with a 417
(Expectation Failed) status if any of the expectations cannot be met
or, if there are other problems with the request, some other 4xx
status.



Since:4.0
/**
 * Defines an interface to verify whether an incoming HTTP request meets
 * the target server's expectations.
 *<p>
 * The Expect request-header field is used to indicate that particular
 * server behaviors are required by the client.
 *</p>
 *<pre>
 *    Expect       =  "Expect" ":" 1#expectation
 *
 *    expectation  =  "100-continue" | expectation-extension
 *    expectation-extension =  token [ "=" ( token | quoted-string )
 *                             *expect-params ]
 *    expect-params =  ";" token [ "=" ( token | quoted-string ) ]
 *</pre>
 *<p>
 * A server that does not understand or is unable to comply with any of
 * the expectation values in the Expect field of a request MUST respond
 * with appropriate error status. The server MUST respond with a 417
 * (Expectation Failed) status if any of the expectations cannot be met
 * or, if there are other problems with the request, some other 4xx
 * status.
 *</p>
 *
 * @since 4.0
 */
public interface HttpExpectationVerifier {

    
Verifies whether the given request meets the server's expectations.

 If the request fails to meet particular criteria, this method can trigger a terminal response back to the client by setting the status code of the response object to a value greater or equal to 200. In this case the client will not have to transmit the request body. If the request meets expectations this method can terminate without modifying the response object. Per default the status code of the response object will be set to 100. 
Params:
  • request – the HTTP request.
  • response – the HTTP response.
  • context – the HTTP context.
Throws:
/**
     * Verifies whether the given request meets the server's expectations.
     * <p>
     * If the request fails to meet particular criteria, this method can
     * trigger a terminal response back to the client by setting the status
     * code of the response object to a value greater or equal to
     * {@code 200}. In this case the client will not have to transmit
     * the request body. If the request meets expectations this method can
     * terminate without modifying the response object. Per default the status
     * code of the response object will be set to {@code 100}.
     *
     * @param request the HTTP request.
     * @param response the HTTP response.
     * @param context the HTTP context.
     * @throws HttpException in case of an HTTP protocol violation.
     */
    void verify(HttpRequest request, HttpResponse response, HttpContext context)
            throws HttpException;

}