org.wings.session.SessionManager.java Source code

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Here is the source code for org.wings.session.SessionManager.java

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/*
 * $Id$
 * Copyright 2000,2005 wingS development team.
 *
 * This file is part of wingS (http://www.j-wings.org).
 *
 * wingS 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.
 *
 * Please see COPYING for the complete licence.
 */
package org.wings.session;

import org.apache.commons.logging.Log;
import org.apache.commons.logging.LogFactory;

/**
 * A global way to access the current session. FIXME: should this be
 * called SessionManager, then ?
 *
 * @author <a href="mailto:engels@mercatis.de">Holger Engels</a>
 * @version $Revision$
 */
public class SessionManager {
    private final transient static Log log = LogFactory.getLog(SessionManager.class);
    private static ThreadLocal<Session> currentSession = null;

    /**
     * Lazy and synchronized initialize the ThreadLocal to avoid race-conditions.
     *
     * @return ThreadLocal possibly holding the current session if available.
     */
    private static synchronized ThreadLocal<Session> getCurrentSession() {
        if (currentSession == null) {
            currentSession = new ThreadLocal<Session>();
        }

        return currentSession;
    }

    /**
     * Get the Session that is currently associated with this Thread.
     *
     * @return the Session
     */
    public static Session getSession() {
        return (Session) getCurrentSession().get();
    }

    /**
     * Associate the Session with the current Thread.
     * This method must only be called by the SessionServlet before
     * a request is going to be dispatched.
     *
     * @param session the Session
     */
    public static void setSession(Session session) {
        getCurrentSession().set(session);
    }

    public static void removeSession() {
        getCurrentSession().set(null);
    }
}