/*
 * Copyright (c) 2011, 2017 Oracle and/or its affiliates. All rights reserved.
 *
 * This program and the accompanying materials are made available under the
 * terms of the Eclipse Public License v. 2.0, which is available at
 * http://www.eclipse.org/legal/epl-2.0.
 *
 * This Source Code may also be made available under the following Secondary
 * Licenses when the conditions for such availability set forth in the
 * Eclipse Public License v. 2.0 are satisfied: GNU General Public License,
 * version 2 with the GNU Classpath Exception, which is available at
 * https://www.gnu.org/software/classpath/license.html.
 *
 * SPDX-License-Identifier: EPL-2.0 OR GPL-2.0 WITH Classpath-exception-2.0
 */

package org.glassfish.grizzly.servlet;

import java.io.IOException;
import javax.servlet.http.HttpServletRequest;
import javax.servlet.http.HttpServletResponse;

Handler, responsible for processing Expect: header in a HTTP requests,
for example "Expect: 100-Continue"
Author:
Alexey Stashok/**
 * Handler, responsible for processing Expect: header in a HTTP requests,
 * for example "Expect: 100-Continue"
 * 
 * @author Alexey Stashok
 */
public interface ExpectationHandler {
    
Method is getting called by framework if HTTP request contains "Expect" header. Depending on request information, implementation may decide to accept or refuse the HTTP message payload, using passed AckAction. Use AckAction.acknowledge() to confirm expectation, or AckAction.fail() to refuse it. 
Params:
request – HttpServletRequest
response – HttpServletRequest
action – AckAction.
Throws:
Exception – /**
     * Method is getting called by framework if HTTP request contains "Expect"
     * header.
     * Depending on request information, implementation may decide to accept
     * or refuse the HTTP message payload, using passed {@link AckAction}.
     * Use {@link AckAction#acknowledge()} to confirm expectation, or
     * {@link AckAction#fail()} to refuse it.
     * 
     * @param request {@link HttpServletRequest}
     * @param response {@link HttpServletRequest}
     * @param action {@link AckAction}.
     * 
     * @throws Exception 
     */
    void onExpectAcknowledgement(final HttpServletRequest request,
                                 final HttpServletResponse response, final AckAction action)
            throws Exception;
    
    
Interface, using which ExpectationHandler may confirm or refuse client expectation. /**
     * Interface, using which {@link ExpectationHandler} may confirm or refuse
     * client expectation.
     */
    interface AckAction {
        
Acknowledges a client that server wants to receive payload.
Throws:
IOException – /**
         * Acknowledges a client that server wants to receive payload.
         * 
         * @throws IOException 
         */
        void acknowledge() throws IOException;
        
        
Notifies a client that server doesn't want to process HTTP message
payload.
Throws:
IOException – /**
         * Notifies a client that server doesn't want to process HTTP message
         * payload.
         * 
         * @throws IOException 
         */
        void fail() throws IOException;
    }
}