//
//  ========================================================================
//  Copyright (c) 1995-2014 Mort Bay Consulting Pty. Ltd.
//  ------------------------------------------------------------------------
//  All rights reserved. This program and the accompanying materials
//  are made available under the terms of the Eclipse Public License v1.0
//  and Apache License v2.0 which accompanies this distribution.
//
//      The Eclipse Public License is available at
//      http://www.eclipse.org/legal/epl-v10.html
//
//      The Apache License v2.0 is available at
//      http://www.opensource.org/licenses/apache2.0.php
//
//  You may elect to redistribute this code under either of these licenses.
//  ========================================================================
//

package org.eclipse.jetty.continuation;

import java.lang.reflect.Constructor;
import javax.servlet.ServletRequest;
import javax.servlet.ServletRequestWrapper;
import javax.servlet.ServletResponse;

/* ------------------------------------------------------------ */
/** ContinuationSupport.
 *
 * Factory class for accessing Continuation instances, which with either be
 * native to the container (jetty >= 6), a servlet 3.0 or a faux continuation.
 *
 */
public class ContinuationSupport
{
	/* ------------------------------------------------------------ */
	/**
	 * Get a Continuation.  The type of the Continuation returned may
	 * vary depending on the container in which the application is
	 * deployed. It may be an implementation native to the container (eg
	 * org.eclipse.jetty.server.AsyncContinuation) or one of the utility
	 * implementations provided such as an internal <code>FauxContinuation</code>
	 * or a real implementation like {@link org.eclipse.jetty.continuation.Servlet3Continuation}.
	 * @param request The request
	 * @return a Continuation instance
	 */
	public static Continuation getContinuation(ServletRequest request)
	{
		Continuation continuation = (Continuation) request.getAttribute(Continuation.ATTRIBUTE);
		if (continuation!=null)
			return continuation;

		throw new IllegalStateException("!(Jetty || Servlet 3.0 || ContinuationFilter)");
	}
}