001 /**
002 *
003 * $Revision: 14998 $ $Date: 2009-03-24 14:08:58 +0100 (Tue, 24 Mar 2009) $
004 *
005 * This file is part of ** M y C o R e **
006 * Visit our homepage at http://www.mycore.de/ for details.
007 *
008 * This program is free software; you can use it, redistribute it
009 * and / or modify it under the terms of the GNU General Public License
010 * (GPL) as published by the Free Software Foundation; either version 2
011 * of the License or (at your option) any later version.
012 *
013 * This program is distributed in the hope that it will be useful, but
014 * WITHOUT ANY WARRANTY; without even the implied warranty of
015 * MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE. See the
016 * GNU General Public License for more details.
017 *
018 * You should have received a copy of the GNU General Public License
019 * along with this program, normally in the file license.txt.
020 * If not, write to the Free Software Foundation Inc.,
021 * 59 Temple Place - Suite 330, Boston, MA 02111-1307 USA
022 *
023 **/
024 package org.mycore.common.events;
025
026 import java.util.Enumeration;
027
028 import javax.servlet.http.HttpSession;
029 import javax.servlet.http.HttpSessionBindingEvent;
030 import javax.servlet.http.HttpSessionBindingListener;
031 import javax.servlet.http.HttpSessionEvent;
032 import javax.servlet.http.HttpSessionListener;
033
034 import org.apache.log4j.Logger;
035 import org.mycore.common.MCRSession;
036
037 /**
038 * Handles different HttpSession events.
039 *
040 * This class is used to free up MCRSessions when their associated HttpSession
041 * is destroyed or a new MCRSession replaces an old one.
042 *
043 * @author Thomas Scheffler (yagee)
044 */
045 public class MCRHttpSessionListener implements HttpSessionListener, HttpSessionBindingListener {
046 Logger LOGGER = Logger.getLogger(MCRHttpSessionListener.class);
047
048 /*
049 * (non-Javadoc)
050 *
051 * @see javax.servlet.http.HttpSessionListener#sessionCreated(javax.servlet.http.HttpSessionEvent)
052 */
053 public void sessionCreated(HttpSessionEvent hse) {
054 }
055
056 /*
057 * (non-Javadoc)
058 *
059 * @see javax.servlet.http.HttpSessionListener#sessionDestroyed(javax.servlet.http.HttpSessionEvent)
060 */
061 @SuppressWarnings("unchecked")
062 public void sessionDestroyed(HttpSessionEvent hse) {
063 // clear MCRSessions
064 LOGGER.debug("HttpSession will be destroyed, clearing up.");
065 HttpSession httpSession = hse.getSession();
066 LOGGER.debug("Removing any MCRSessions from HttpSession");
067 for (Enumeration<String> e = httpSession.getAttributeNames(); e.hasMoreElements();) {
068 String key = e.nextElement();
069 if (httpSession.getAttribute(key) instanceof MCRSession) {
070 MCRSession mcrSession = (MCRSession) httpSession.getAttribute(key);
071 mcrSession.close();
072 // remove reference in httpSession
073 httpSession.removeAttribute(key);
074 }
075 }
076 LOGGER.debug("Clearing up done");
077 }
078
079 public void valueBound(HttpSessionBindingEvent hsbe) {
080 }
081
082 public void valueUnbound(HttpSessionBindingEvent hsbe) {
083 LOGGER.debug("Attribute " + hsbe.getName() + " is beeing unbound from session");
084 Object obj = hsbe.getValue();
085 if (obj instanceof MCRSession) {
086 MCRSession mcrSession = (MCRSession) obj;
087 mcrSession.close();
088 }
089 LOGGER.debug("Attribute " + hsbe.getName() + " is unbounded from session");
090 }
091
092 }