sessioncache.java

Sun公司Dream项目

/*
 * The contents of this file are subject to the terms
 * of the Common Development and Distribution License
 * (the "License").  You may not use this file except
 * in compliance with the License.
 *
 * You can obtain a copy of the license at
 * http://www.opensource.org/licenses/cddl1.php
 * See the License for the specific language governing
 * permissions and limitations under the License.
 *
 * When distributing Covered Code, include this CDDL
 * HEADER in each file and include the License file at
 * http://www.opensource.org/licenses/cddl1.php.  If 
 * applicable, add the following below this CDDL HEADER, 
 * with the fields enclosed by brackets "[]" replaced 
 * with your own identifying information: 
 * Portions Copyright [yyyy]
 * [name of copyright owner]
 */ 

/*
 * $(@)SessionCache.java $Revision: 1.1.1.1 $ $Date: 2006/07/24 21:56:11 $
 * 
 * Copyright 2006 Sun Microsystems, Inc. All Rights Reserved.
 */


/*
 * @(#)SessionCache.java  1.1 05/11/09
 *
 * Copyright 2002-2005 Sun Microsystems, Inc. All Rights Reserved.
 */


package com.sun.dream.shop;

import java.util.Hashtable;

/**
 *
 * SessionCache class acts as cache manager for storing session-scoped objects.
 * It supports the following interfaces:
 * Object getAttribute (String sessionId, String name) 
 * void   setAttribute (String sessionId, String name, Object value)
 * void   removeAttribute (String sessionId, String name)
 * void   invalidateSession (String sessionId)
 */
public class SessionCache {
    Hashtable cache;
    
    public SessionCache() {
        cache = new Hashtable();
    };
    
    public void setAttribute (String sessionId, String name, Object value) {
        if ((sessionId != null) && (name != null)) {
            Hashtable sessionTable = (Hashtable)cache.get(sessionId);
            if (sessionTable == null)
                sessionTable = new Hashtable();
            sessionTable.put(name, value);
            cache.put(sessionId, sessionTable);
        }
    }
    
    public Object getAttribute (String sessionId, String name) {
        if ((sessionId == null) || (name == null))
            return null;
        Hashtable sessionTable = (Hashtable) cache.get(sessionId);
        if (sessionTable == null)
            return null;
        else
            return sessionTable.get(name);
    }

    public void removeAttribute (String sessionId, String name) {
        if ((sessionId != null) && (name != null)) {
            Hashtable sessionTable = (Hashtable) cache.get(sessionId);
            if (sessionTable != null) {
                sessionTable.remove(name);
                cache.put(sessionId, sessionTable);
            }
        }
    }
        
    public void invalidateSession (String sessionId) {
        if (sessionId != null)
            cache.remove(sessionId);
    }
}