userrightscache.java

iiitAccessServer是一个用Java编写的基于规则的企业鉴别系统。它作为一个服务器工作

/*******************************************************************************
 * Copyright (C) 2002, 2003
 * ingenieurbuero fuer innovative informationstechnik (iiit)
 * Dipl.-Ing. Joerg Beckmann, Dortmund, Germany
 *
 * 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, write to the Free Software
 * Foundation, Inc., 59 Temple Place, Suite 330, Boston, MA  02111-1307  USA
 * or look at http://www.gnu.org/copleft/lesser.html.
 *
 * version $Id: UserRightsCache.java,v 1.5 2003/04/13 21:13:38 joerg Exp $
 ******************************************************************************/

package de.iiit.access.common.cache;

import de.iiit.cache.*;

/** This cache is used by the CachePlugin 
 * @version $Revision: 1.5 $ $Date: 2003/04/13 21:13:38 $
 */
public class UserRightsCache extends GenericTimeoutCache
{
    /** CVS Version Tag */
    private static final String vcid = "$Id: UserRightsCache.java,v 1.5 2003/04/13 21:13:38 joerg Exp $";
        
    int invalidationTimeout;
    
    /** Creates a new instance of UserRightsCache */
    public UserRightsCache()
    {
        this(-1, 1800000, 10000);
    }

    /** Creates a new instance of UserRightsCache
     * @param lruTimeout after this period of time an unused cache for a specific user will
     *                      be deleted.
     */    
    public UserRightsCache(int lruTimeout)
    {
        this(lruTimeout, 1800000, 10000);
    }
    
    /** Creates a new instance of UserRightsCache
     * @param lruTimeout after this period of time an unused cache for a specific user will
     * be deleted. It does not make any sense to set this timeout
     * higher than the invalidation timeout.
     * @param invalidationTimeout after this period of time any elements in the cache will
     * be ignored to assure that changes in the rights will be recognized.
     * @param sleeptime The time to sleep between to runs of the cache cleaner.
     */    
    public UserRightsCache(int lruTimeout, int invalidationTimeout, int sleeptime)
    {
        super(lruTimeout, sleeptime);

        this.invalidationTimeout = invalidationTimeout;
    }

    /** Adds the result of one expression to the cache of the user.
     * @param user The name of the user
     * @param expression The expression
     * @param isAllowed The result of the expression
     */    
    public void addUserRight(String user, String expression, boolean isAllowed)
    {
        RightsCache rc;
        
        try
        {
            rc = (RightsCache) getElement(user);
        }
        catch(CacheFaultException e)
        {
            rc = new RightsCache(invalidationTimeout);
            addElement(user, rc);
        }
        
        rc.addRight(expression, isAllowed);
    }
    
    /** Retrieves the result of an expression from the cache.
     * @param user The name of the user for whom the result is needed.
     * @param expression The expression
     * @throws CacheFaultException if the result is not found in the cache
     * @return the result of the expression
     */    
    public boolean getUserRight(String user, String expression) throws CacheFaultException
    {
        RightsCache rc = (RightsCache) getElement(user);
        return rc.getRight(expression);
    }

}

/**
 * $Log: UserRightsCache.java,v $
 * Revision 1.5  2003/04/13 21:13:38  joerg
 * Copyright statements changed to LGPL
 *
 * Revision 1.4  2003/04/13 20:16:41  joerg
 * Package structure modified
 *
 * Revision 1.3  2003/01/01 21:04:17  joerg
 * Copyright-Statement aktualisiert
 *
 * Revision 1.2  2002/12/22 20:45:12  joerg
 * shutdown()-Methode eingebaut
 *
 * Revision 1.1  2002/12/19 15:24:23  joerg
 * Reparatur des CVS-Repositories
 *
 * Revision 1.4  2002/12/09 19:29:17  joerg
 * Versionsdaten in allen JavaDoc-Klassenbeschreibungen ergaenzt
 *
 * Revision 1.3  2002/12/09 16:32:26  joerg
 * JavaDoc Kommentare ergaenzt
 *
 * Revision 1.2  2002/11/19 20:22:52  joerg
 * Das invalidationTimeout fuer den RightsCache kann jetzt auch
 * beim Anlegen des Caches gesetzt werden.
 *
 * Revision 1.1  2002/11/02 18:23:32  joerg
 * Klasse verschoben ins Package 'cache'
 *
 * Revision 1.1  2002/11/01 21:36:47  joerg
 * Version mit funktionierenden 1st-level Cache
 *
 */