onlineusermanager.java

easy to use, easy to setup bulletin board (forum)

/*
 * Copyright (C) 2002 by MyVietnam.net
 *
 * This program is free software; you can redistribute it and/or
 * modify it under the terms of the GNU General Public License
 * as published by the Free Software Foundation; either version 2
 * of the License, or any later version.
 *
 * All copyright notices regarding mvnForum
 * must remain intact in the scripts and in the outputted HTML
 * The "powered by" text/logo with a link back to
 * http://www.mvnForum.com and http://www.MyVietnam.net in the footer of the pages MUST
 * remain visible when the pages are viewed on the internet or intranet.
 *
 * This program 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 General Public License for more details.
 *
 * You should have received a copy of the GNU General Public License
 * along with this program; if not, write to the Free Software
 * Foundation, Inc., 59 Temple Place - Suite 330, Boston, MA  02111-1307, USA.
 *
 * Support can be obtained from support forums at:
 * http://www.mvnForum.com/mvnforum/index
 *
 * Correspondence and Marketing Questions can be sent to:
 * [e-mail]
 *
 * @author: Minh Nguyen  [e-mail]
 * @author: Mai  Nguyen  [e-mail]
 */
package net.myvietnam.mvnplugin.mvnforum.auth;

import java.util.*;
import java.sql.Timestamp;
import javax.servlet.http.HttpServletRequest;
import javax.servlet.http.HttpSession;
import net.myvietnam.mvncore.exception.DatabaseException;
import net.myvietnam.mvncore.exception.AssertionException;
import net.myvietnam.mvncore.exception.BadInputException;
import net.myvietnam.mvncore.exception.NotLoginException;
import net.myvietnam.mvncore.util.ParamUtil;
import net.myvietnam.mvncore.util.DateUtil;
import net.myvietnam.mvncore.security.Encoder;
import net.myvietnam.mvnplugin.mvnforum.MVNForumConfig;

public class OnlineUserManager {
    private static final int REMOVE_INTERVAL = 2000; //update every 2 second
    private static final String MVNFORUM_SESSION_USERNAME = "mvnforum.membername";
    private static final String MVNFORUM_SESSION_PASSWORD = "mvnforum.encodedpassword";

    //static variable
    private static OnlineUserManager instance = new OnlineUserManager();

    //instance variable
    private Map userMap = new TreeMap();
    private long timeOfLastRemoveAction = 0;
    private transient Vector onlineUserListeners;

    private OnlineUserManager() {
    }

    public static OnlineUserManager getInstance() {
        return instance;
    }

    /**
     * Util method to be called from Processor.
     * It assumes that to input parameters are
     * MemberName      for username
     * MemberMatkhau   for password
     */
    public void processLogin(HttpServletRequest request)
        throws AuthenticationException, AssertionException, DatabaseException, BadInputException {

        String memberName      = ParamUtil.getParameter(request, "MemberName", true);
        String memberPassword  = ParamUtil.getParameter(request, "MemberMatkhau", true);
        String encodedPassword = Encoder.getMD5_Base64(memberPassword);

        try {
            login(request, memberName, encodedPassword);
        } catch (AuthenticationException ex) {
            if (ex.getReason() == NotLoginException.WRONG_PASSWORD) {
                request.setAttribute("MemberName", memberName);// so user dont have to retype USER NAME
            }
            throw ex;
        }
    }

    /**
     * NOTE: This method MUST be the only way to authenticate a user
     */
    public OnlineUser login(HttpServletRequest request, String memberName, String encodedPassword)
        throws AuthenticationException, DatabaseException, AssertionException {
        OnlineUser user = OnlineUserFactory.getAuthenticatedUser(memberName, encodedPassword);

        HttpSession session = request.getSession();
        String sessionID = session.getId();
        setOnlineUser(sessionID, user);

        // now save the login info in the session
        session.setAttribute(MVNFORUM_SESSION_USERNAME, memberName);
        session.setAttribute(MVNFORUM_SESSION_PASSWORD, encodedPassword);
        return user;
    }

    public void logout(HttpServletRequest request)
        throws DatabaseException, AssertionException {

        OnlineUser user = OnlineUserFactory.getAnonymousUser();
        HttpSession session = request.getSession();
        String sessionID = session.getId();
        setOnlineUser(sessionID, user);
    }

    public OnlineUser getOnlineUser(HttpServletRequest request)
        throws AuthenticationException, DatabaseException, AssertionException {

        long currentTime = System.currentTimeMillis();
        if (currentTime - timeOfLastRemoveAction > REMOVE_INTERVAL) {//update every minute
            removeTimeoutUsers();
            // update MostOnline here
            int currentOnlineUserCount = userMap.size();
            fireDataChanged(new OnlineUserEvent(this, currentOnlineUserCount));
        }

        HttpSession session = request.getSession();
        String sessionID = session.getId();
        OnlineUser user = getOnlineUser(sessionID);
        if (user == null) {
            boolean haveLoginInfoInCookie = false;
            boolean haveLoginInfoInSession = false;
            String memberName = null;
            String encodedPassword = null;
            memberName = ParamUtil.getAttribute(session, MVNFORUM_SESSION_USERNAME);
            encodedPassword = ParamUtil.getAttribute(session, MVNFORUM_SESSION_PASSWORD);
            if ( (memberName.length() > 0) && (encodedPassword.length() > 0) ) {
                haveLoginInfoInSession = true;
            }

            if (haveLoginInfoInSession) {
                user = login(request, memberName, encodedPassword);
            } else if (haveLoginInfoInCookie) {
                user = login(request, memberName, encodedPassword);
            } else {
                user = OnlineUserFactory.getAnonymousUser();
                setOnlineUser(sessionID, user);
            }
        }
        user.getOnlineUserAction().updateLastRequestTime();
        return user;
    }

    public Collection getOnlineUserActions(int sortOption) {

        Collection collection = userMap.values();
        // @todo: find a better sollution, I dont want to copy the Collection
        // this ArrayList is used to copy the values
        ArrayList retValue = new ArrayList(collection.size());

        Iterator iterator = collection.iterator();
        while (iterator.hasNext()) {
            OnlineUser onlineUser = (OnlineUser)iterator.next();
            OnlineUserAction onlineUserAction = onlineUser.getOnlineUserAction();
            retValue.add(onlineUserAction);
        }
        return retValue;
    }

    public void updateOnlineUserAction(HttpServletRequest request, Action action)
        throws AssertionException, DatabaseException, AuthenticationException {
        if (action != null) {
            OnlineUser onlineUser = getOnlineUser(request);
            OnlineUserAction onlineUserAction = onlineUser.getOnlineUserAction();
            // the setAction has package-default access
            // so this is the only way to set action to a user
            onlineUserAction.setAction(action);
        }
    }

/************************************************************************
 * private methods
 ************************************************************************/
    private synchronized OnlineUser getOnlineUser(String sessionID) {
        return (OnlineUser)userMap.get(sessionID);
    }

    private synchronized void setOnlineUser(String sessionID, OnlineUser user) {
        userMap.put(sessionID, user);
    }

    private synchronized void removeTimeoutUsers() {
        long currentTimeMillis = System.currentTimeMillis();
        // try to resolve problem with synchronization on the class-varible : timeOfLastRemoveAction
        if (currentTimeMillis - timeOfLastRemoveAction < REMOVE_INTERVAL) {
            return;
        }
        // okie now, go ahead
        timeOfLastRemoveAction = currentTimeMillis;

        Timestamp currentTime = DateUtil.getCurrentGMTTimestamp();

        Collection collection = userMap.values();
        Iterator iterator = collection.iterator();
        while (iterator.hasNext()) {
            OnlineUser onlineUser = (OnlineUser)iterator.next();
            OnlineUserAction onlineUserAction = onlineUser.getOnlineUserAction();
            long duration = currentTime.getTime() - onlineUserAction.getLastRequestTime().getTime();
            if (duration > MVNForumConfig.SESSION_DURATION) {
                iterator.remove();
            }
        }
    }

    /************************************************************************
     * Event method
     ************************************************************************/
    public synchronized void removeOnlineUserListener(OnlineUserListener l) {
        if (onlineUserListeners != null && onlineUserListeners.contains(l)) {
            Vector v = (Vector) onlineUserListeners.clone();
            v.removeElement(l);
            onlineUserListeners = v;
        }
    }
    public synchronized void addOnlineUserListener(OnlineUserListener l) {
        Vector v = onlineUserListeners == null ? new Vector(2) : (Vector) onlineUserListeners.clone();
        if (!v.contains(l)) {
            v.addElement(l);
            onlineUserListeners = v;
        }
    }

    protected void fireDataChanged(OnlineUserEvent e) {
        if (onlineUserListeners != null) {
            Vector listeners = onlineUserListeners;
            int count = listeners.size();
            for (int i = 0; i < count; i++) {
                ((OnlineUserListener) listeners.elementAt(i)).dataChanged(e);
            }
        }
    }
}