Metacat

/**

 *  '$RCSfile$'

 *    Purpose: A Class that implements session utility methods

 *  Copyright: 2008 Regents of the University of California and the

 *             National Center for Ecological Analysis and Synthesis

 *    Authors: Michael Daigle

 *

 *   '$Author$'

 *     '$Date$'

 * '$Revision$'

 *

 * This program is free software; you can redistribute it and/or modify

 * it under the terms of the GNU General Public License as published by

 * the Free Software Foundation; either version 2 of the License, or

 * (at your option) any later version.

 *

 * This program 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 General Public License for more details.

 *

 * You should have received a copy of the GNU General Public License

 * along with this program; if not, write to the Free Software

 * Foundation, Inc., 59 Temple Place, Suite 330, Boston, MA  02111-1307  USA

 */

package edu.ucsb.nceas.metacat.service;

import java.util.Calendar;

import edu.ucsb.nceas.metacat.shared.ServiceException;

	private static SessionService sessionService = null;

	private static Logger logMetacat = Logger.getLogger(SessionService.class);

	private static Hashtable<String, SessionData> sessionHash = null;

	/**

	 * private constructor since this is a singleton

	 */

		_serviceName = "SessionService";

		try {

			sessionHash = new Hashtable<String, SessionData>();

			sessionTimeoutStr = PropertyService.getProperty("session.timeoutMinutes");

			sessionTimeoutMinutes = Integer.parseInt(sessionTimeoutStr);

			logMetacat.debug("SessionService() - Registering public session id: " +

					PUBLIC_SESSION_ID);

			throw new ServiceException("SessionService() - Error getting property: " +

					pnfe.getMessage());

		} catch (NumberFormatException nfe) {

			throw new ServiceException("SessionService() - Error parsing session timeout minutes: " +

					sessionTimeoutStr);

		}

	/**

			sessionService = new SessionService();

		}

		return sessionService;

	}

		return false;

	}

	}

		return;

	}

	 * Register a session in the session hash table.  This uses

	 * the parameters passed in to create a SessionData object.

	 *

	 * @param sessionId

	 *            the ID of the session to register

	 * @param userName

	 *            the user name of the session

	 * @param groupNames

	 *            the group names for the session

	 * @param password

	 *            the password for the session

	 */

					"Cannot register a null session id");

	}

	 * Register a session in the session hash table.

	 *

	 * @param sessionData

	 *            the session data object to add to the session hash

	 */

		if (sessionData == null) {

					"Cannot register null session data");

				"data with id: " + sessionData.getId());

	}

	 * Unregister a session from the session hash table.

	 *

	 * @param sessionId

	 *            the id of the session to remove.

	 */

					"unregister a session with null id");

		logMetacat.error("SessionService.unRegisterSession - unRegistering session: " + sessionId);

		sessionHash.remove(sessionId);

	 * Check if a session is registered in the session hash table.

	 *

	 * @param sessionId

	 *            the id of the session to look for.

	 */

					"session with null id is registered");

		}

		checkTimeout(sessionId);

	}

	 * in XML format to output.

	 *

	 * @param out

	 *            the output stream to write to.

	 * @param sessionId

	 *            the id of the session to look for.

	 */

	public static void validateSession(PrintWriter out, HttpServletResponse response,

			String sessionId) {

		response.setContentType("text/xml");

		out.println("<?xml version=\"1.0\"?>");

		out.write("<validateSession><status>");

		} else {

			out.write("invalid");

		}

		out.write("</status>");

		out.write("<sessionId>" + sessionId + "</sessionId></validateSession>");

	}

	/**

	 * true if the session is valid and false otherwise.

	 *

	 * @param sessionId

	 *            the id of the session to look for.

	 */

	public static boolean validateSession(String sessionId) {

		if (sessionId != null && !sessionId.equals(PUBLIC_SESSION_ID) && isSessionRegistered(sessionId)) {

			return true;

		} else {

			return false;

		}

	}

	/**

	 * TODO MCD need to time sessions out

	 *

	 * @param sessionId

	 *            the id of the session to retrieve.

	 */

		}

	}

	 * Get the public session from the session hash table.

	 */

	public static SessionData getPublicSession() {

		return sessionHash.get(PUBLIC_SESSION_ID);

	 * Keep a session active by updating its last accessed time.

	 *

	 * @param sessionId

	 *            the id of the session to update.

	 */

			sessionData.setLastAccessedTime();

		}

	}

	private static void checkTimeout (String sessionId) {

		SessionData sessionData = null;

		if ((sessionData = sessionHash.get(sessionId)) != null) {

			Calendar expireTime = Calendar.getInstance();

			Calendar lastAccessedTime = sessionData.getLastAccessedTime();

			expireTime.add(Calendar.MINUTE, 0 - sessionTimeoutMinutes);

			if(lastAccessedTime.compareTo(expireTime) < 0 ) {

				unRegisterSession(sessionId);

			}

		}

	}

}