sessionpreferences.java

来自「RESIN 3.2 最新源码」· Java 代码 · 共 119 行

/*
 * The Apache Software License, Version 1.1
 *
 * Copyright (c) 2001-2004 Caucho Technology, Inc.  All rights reserved.
 *
 * Redistribution and use in source and binary forms, with or without
 * modification, are permitted provided that the following conditions
 * are met:
 *
 * 1. Redistributions of source code must retain the above copyright
 *    notice, this list of conditions and the following disclaimer.
 *
 * 2. Redistributions in binary form must reproduce the above copyright
 *    notice, this list of conditions and the following disclaimer in
 *    the documentation and/or other materials provided with the
 *    distribution.
 *
 * 3. The end-user documentation included with the redistribution, if
 *    any, must include the following acknowlegement:
 *       "This product includes software developed by the
 *        Caucho Technology (http://www.caucho.com/)."
 *    Alternately, this acknowlegement may appear in the software itself,
 *    if and wherever such third-party acknowlegements normally appear.
 *
 * 4. The names "Hessian", "Resin", and "Caucho" must not be used to
 *    endorse or promote products derived from this software without prior
 *    written permission. For written permission, please contact
 *    [e-mail].
 *
 * 5. Products derived from this software may not be called "Resin"
 *    nor may "Resin" appear in their names without prior written
 *    permission of Caucho Technology.
 *
 * THIS SOFTWARE IS PROVIDED ``AS IS'' AND ANY EXPRESSED OR IMPLIED
 * WARRANTIES, INCLUDING, BUT NOT LIMITED TO, THE IMPLIED WARRANTIES
 * OF MERCHANTABILITY AND FITNESS FOR A PARTICULAR PURPOSE ARE
 * DISCLAIMED.  IN NO EVENT SHALL CAUCHO TECHNOLOGY OR ITS CONTRIBUTORS
 * BE LIABLE FOR ANY DIRECT, INDIRECT, INCIDENTAL, SPECIAL, EXEMPLARY,
 * OR CONSEQUENTIAL DAMAGES (INCLUDING, BUT NOT LIMITED TO, PROCUREMENT
 * OF SUBSTITUTE GOODS OR SERVICES; LOSS OF USE, DATA, OR PROFITS; OR
 * BUSINESS INTERRUPTION) HOWEVER CAUSED AND ON ANY THEORY OF LIABILITY,
 * WHETHER IN CONTRACT, STRICT LIABILITY, OR TORT (INCLUDING NEGLIGENCE
 * OR OTHERWISE) ARISING IN ANY WAY OUT OF THE USE OF THIS SOFTWARE, EVEN
 * IF ADVISED OF THE POSSIBILITY OF SUCH DAMAGE.
 *
 * @author Sam
 */

package com.caucho.portal.generic;

import javax.servlet.http.HttpSession;
import javax.servlet.http.HttpSessionActivationListener;
import javax.servlet.http.HttpSessionBindingEvent;
import javax.servlet.http.HttpSessionBindingListener;
import javax.servlet.http.HttpSessionEvent;
import java.lang.ref.WeakReference;
import java.util.LinkedHashMap;

public class SessionPreferences
  extends LinkedHashMap<String, String[]>
  implements java.io.Serializable,
             HttpSessionBindingListener, HttpSessionActivationListener
{
  transient WeakReference _sessionRef;
  transient private boolean _isUpdateNeeded;

  private String _sessionAttributeName;

  public SessionPreferences()
  {
  }

  public void valueBound(HttpSessionBindingEvent event)
  {
    if (_sessionRef == null) {
      _sessionRef = new WeakReference(event.getSession());
      _sessionAttributeName = event.getName();
    }
  }

  public void valueUnbound(HttpSessionBindingEvent event)
  {
    _sessionRef = null;
    _sessionAttributeName = null;
  }

  public void sessionDidActivate(HttpSessionEvent event)
  {
    _sessionRef = new WeakReference(event.getSession());
  }

  public void sessionWillPassivate(HttpSessionEvent event)
  {
  }

  public String[] put(String key, String[] value)
  {
    _isUpdateNeeded = true;
    return super.put(key, value);
  }

  void updateSessionIfNeeded()
  {
    if (_isUpdateNeeded) {
      if (_sessionRef != null) {
        HttpSession session = (HttpSession) _sessionRef.get();

        if (session != null) {
          synchronized (session) {
            session.setAttribute(_sessionAttributeName, this);
            _isUpdateNeeded = false;
          }
        }
      }
    }
  }
}