ingo@1022: /*
ingo@1022:  * Copyright (c) 2010 by Intevation GmbH
ingo@1022:  *
ingo@1022:  * This program is free software under the LGPL (>=v2.1)
ingo@1022:  * Read the file LGPL.txt coming with the software for details
ingo@1022:  * or visit http://www.gnu.org/licenses/ if it does not exist.
ingo@1022:  */
ingo@1022: 
tim@8: package de.intevation.gnv.action.sessionmodel;
tim@8: 
tim@8: import javax.servlet.http.HttpServletRequest;
tim@8: 
tim@8: import org.apache.log4j.Logger;
tim@8: 
tim@8: /**
ingo@690:  * Creates and restores <code>SessionModel</code> objects from <code>
ingo@690:  * HttpServletRequest</code>.
sascha@699:  *
sascha@684:  * @author <a href="mailto:tim.englich@intevation.de">Tim Englich</a>
tim@8:  */
tim@8: public class SessionModelFactory {
tim@36: 
tim@954:     /**
tim@954:      * The id of the <code>SessionModel</code> that must be used to lookup the 
tim@954:      * model from the given <code>HttpSession<Code> of the request.
tim@954:      */
tim@954:     public final static String SESSION_MODEL_ID = "de.intevation.gnv.action." +
tim@954:                                                  "sessionmodel.SessionModel.ID";
tim@954: 
tim@8:     /**
tim@8:      * the logger, used to log exceptions and additonaly information
tim@8:      */
tim@8:     private static Logger log = Logger.getLogger(SessionModelFactory.class);
tim@8: 
tim@8:     /**
tim@8:      * The singleton Instance of this Factory.
tim@8:      */
tim@8:     private static SessionModelFactory instance = null;
tim@8: 
tim@8:     /**
tim@8:      * Constructor
tim@8:      */
tim@8:     private SessionModelFactory() {
tim@8:         super();
tim@8:     }
tim@8: 
tim@8:     /**
tim@8:      * This Method provides an singleton Instance of this Class.
tim@8:      * @return an singleton Instance of this Class
tim@8:      */
ingo@394:     public synchronized static SessionModelFactory getInstance() {
tim@954:         log.debug("SessionModelFactory.getInstance");
tim@36:         if (instance == null) {
tim@8:             instance = new SessionModelFactory();
tim@8:         }
tim@8:         return instance;
tim@8:     }
tim@36: 
tim@8:     /**
tim@8:      * Getting the ArtifactDatabaseClient
tim@954:      * @param request the tequest from which the SessionModel should be read.
tim@8:      * @return the ArtifactDatabaseClient
tim@8:      */
tim@36:     public SessionModel getSessionModel(HttpServletRequest request) {
tim@954:         log.debug("SessionModelFactory.getSessionModel");
ingo@394:         synchronized (request) {
tim@8:             SessionModel sm = null;
ingo@394:             Object obj = request.getSession().getAttribute(SESSION_MODEL_ID);
ingo@394:             if (obj instanceof SessionModel) {
ingo@394:                 sm = (SessionModel) obj;
tim@36:             } else {
ingo@706:                 sm = new DefaultSessionModel(request.getLocale());
tim@8:                 request.getSession().setAttribute(SESSION_MODEL_ID, sm);
tim@8:             }
tim@36: 
tim@8:             return sm;
tim@36:         }
tim@8:     }
tim@8: }
sascha@700: // vim:set ts=4 sw=4 si et sta sts=4 fenc=utf-8 :