/*
Wotonomy: OpenStep design patterns for pure Java applications.
Copyright (C) 2003 Intersect Software Corp.

This library is free software; you can redistribute it and/or
modify it under the terms of the GNU Lesser General Public
License as published by the Free Software Foundation; either
version 2.1 of the License, or (at your option) any later version.

This library is distributed in the hope that it will be useful,
but WITHOUT ANY WARRANTY; without even the implied warranty of
MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE.  See the GNU
Lesser General Public License for more details.

You should have received a copy of the GNU Lesser General Public
License along with this library; if not, see http://www.gnu.org
*/

package net.wotonomy.web;

/**
 * An abstract class defining the requirements for persisting session state
 * across user transactions. Used by WOApplication to persist sessions between
 * requests.
 *
 * @author michael@mpowers.net
 * @author $Author: cgruber $
 * @version $Revision: 893 $
 */
public abstract class WOSessionStore {
	private static WOSessionStore serverSessionStore = null;

	/**
	 * Returns the default session store used by WOApplication.
	 */
	public static WOSessionStore serverSessionStore() {
		if (serverSessionStore == null) {
			serverSessionStore = new WOServletSessionStore();
		}
		return serverSessionStore;
	}

	/**
	 * Called by WOApplication after the request-response cycle has ended. The
	 * context's session will again be available for subsequent requests.
	 */
	public final void checkInSessionForContext(WOContext aContext) {
		saveSessionForContext(aContext);
	}

	/**
	 * Returns the session with the specified id for the specified request, or null
	 * if none exist. Subsequent calls for the same id will return null until the
	 * session is checked in again. Called by WOApplication before the
	 * request-response cycle starts.
	 */
	public final WOSession checkOutSessionWithID(String sessionID, WORequest aRequest) {
		return restoreSessionWithID(sessionID, aRequest);
	}

	/**
	 * Removes the WOSession for the specified ID from the store and returns it.
	 */
	public abstract WOSession removeSessionWithID(String sessionID);

	/**
	 * Returns the WOSession for the specified ID from the store.
	 */
	public abstract WOSession restoreSessionWithID(String sessionID, WORequest aRequest);

	/**
	 * Places the context's session into the store.
	 */
	public abstract void saveSessionForContext(WOContext context);
}

/*
 * $Log$ Revision 1.1 2006/02/16 13:22:22 cgruber Check in all sources in
 * eclipse-friendly maven-enabled packages.
 *
 * Revision 1.1 2003/01/07 20:48:29 mpowers Implemented WOSessionStore and
 * WOServletSessionStore.
 *
 *
 */