/*
 * Copyright 2004, 2005, 2006 Acegi Technology Pty Limited
 *
 * Licensed 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.
 */

package org.springframework.security.web.access.channel;

import java.io.IOException;

import javax.servlet.ServletException;
import javax.servlet.http.HttpServletRequest;
import javax.servlet.http.HttpServletResponse;

/**
 * May be used by a {@link ChannelProcessor} to launch a web channel.
 *
 * <p>
 * <code>ChannelProcessor</code>s can elect to launch a new web channel directly, or they
 * can delegate to another class. The <code>ChannelEntryPoint</code> is a pluggable
 * interface to assist <code>ChannelProcessor</code>s in performing this delegation.
 *
 * @author Ben Alex
 */
public interface ChannelEntryPoint {
	// ~ Methods
	// ========================================================================================================

	/**
	 * Commences a secure channel.
	 * <p>
	 * Implementations should modify the headers on the <code>ServletResponse</code> as
	 * necessary to commence the user agent using the implementation's supported channel
	 * type.
	 *
	 * @param request that a <code>ChannelProcessor</code> has rejected
	 * @param response so that the user agent can begin using a new channel
	 *
	 */
	void commence(HttpServletRequest request, HttpServletResponse response)
			throws IOException, ServletException;
}
