logoffaction.java

USB设计的一些源码！适合与USB开发的同学！还是蛮不错的！我用过一些！

/*
 * $Header: /cvsroot/struts/logon/WEB-INF/src/java/app/LogoffAction.java,v 1.1.1.1 2002/08/15 15:50:55 thusted Exp $
 * $Revision: 1.1.1.1 $
 * $Date: 2002/08/15 15:50:55 $
 *
 * ====================================================================
 *
 * The Apache Software License, Version 1.1
 *
 * Copyright (c) 1999 The Apache Software Foundation.  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
 *        Apache Software Foundation (http://www.apache.org/)."
 *    Alternately, this acknowlegement may appear in the software itself,
 *    if and wherever such third-party acknowlegements normally appear.
 *
 * 4. The names "The Jakarta Project", "Tomcat", and "Apache Software
 *    Foundation" 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 "Apache"
 *    nor may "Apache" appear in their names without prior written
 *    permission of the Apache Group.
 *
 * 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 THE APACHE SOFTWARE FOUNDATION 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.
 * ====================================================================
 *
 * This software consists of voluntary contributions made by many
 * individuals on behalf of the Apache Software Foundation.  For more
 * information on the Apache Software Foundation, please see
 * <http://www.apache.org/>.
 *
 */


package app;

import java.io.IOException;
import java.util.Hashtable;
import java.util.Locale;
import java.util.Vector;
import javax.servlet.RequestDispatcher;
import javax.servlet.ServletException;
import javax.servlet.http.HttpServletRequest;
import javax.servlet.http.HttpSession;
import javax.servlet.http.HttpServletResponse;
import org.apache.struts.action.Action;
import org.apache.struts.action.ActionForm;
import org.apache.struts.action.ActionForward;
import org.apache.struts.action.ActionMapping;
import org.apache.struts.action.ActionServlet;
import org.apache.struts.util.MessageResources;


/**
 * Implementation of <strong>Action</strong> that processes a
 * user logoff.
 *
 * @author Craig R. McClanahan
 * @author Ted Husted
 * @version $Revision: 1.1.1.1 $ $Date: 2002/08/15 15:50:55 $
 */

public final class LogoffAction extends Action {


// ---------------------------------------------------- Public Methods

    /**
     * Logoff the user.
     * The event is logged if the debug level is >= Constants.DEBUG.
     *
     * @param mapping The ActionMapping used to select this instance
     * @param actionForm The ActionForm bean for this request (if any)
     * @param request The HTTP request we are processing
     * @param response The HTTP response we are creating
     *
     * @exception IOException if an input/output error occurs
     * @exception ServletException if a servlet exception occurs
     */
    public ActionForward perform(ActionMapping mapping,
         ActionForm form,
         HttpServletRequest request,
         HttpServletResponse response)
            throws IOException, ServletException {

      // Extract attributes we will need
      HttpSession session = request.getSession();
      LogonForm user = (LogonForm)
        session.getAttribute(Constants.USER_KEY);

      // Log this user logoff
      if (user != null) {

        if (servlet.getDebug() >= Constants.DEBUG) {
            StringBuffer message =
                new StringBuffer("LogoffAction: User '");
            message.append(user.getUsername());
            message.append("' logged off in session ");
            message.append(session.getId());
            servlet.log(message.toString());
        }
      }

      else {

        if (servlet.getDebug() >= Constants.DEBUG) {
            StringBuffer message =
                new StringBuffer("LogoffAction: User '");
            message.append(session.getId());
            servlet.log(message.toString());
        }
      }

      // Remove user login
      session.removeAttribute(Constants.USER_KEY);

      // Return success
      return (mapping.findForward(Constants.SUCCESS));

    }

} // end LogoffAction