presenceupdatehandler.java

基于Jabber协议的即时消息服务器

/**
 * $RCSfile: PresenceUpdateHandler.java,v $
 * $Revision: 3125 $
 * $Date: 2005-11-30 15:14:14 -0300 (Wed, 30 Nov 2005) $
 *
 * Copyright (C) 2004 Jive Software. All rights reserved.
 *
 * This software is published under the terms of the GNU Public License (GPL),
 * a copy of which is included in this distribution.
 */

package org.jivesoftware.wildfire.handler;

import org.jivesoftware.util.ConcurrentHashSet;
import org.jivesoftware.util.LocaleUtils;
import org.jivesoftware.util.Log;
import org.jivesoftware.wildfire.*;
import org.jivesoftware.wildfire.auth.UnauthorizedException;
import org.jivesoftware.wildfire.container.BasicModule;
import org.jivesoftware.wildfire.roster.Roster;
import org.jivesoftware.wildfire.roster.RosterItem;
import org.jivesoftware.wildfire.roster.RosterManager;
import org.jivesoftware.wildfire.user.UserManager;
import org.jivesoftware.wildfire.user.UserNotFoundException;
import org.xmpp.packet.*;

import java.util.*;
import java.util.concurrent.ConcurrentHashMap;

/**
 * Implements the presence protocol. Clients use this protocol to
 * update presence and roster information.
 * <p/>
 * The handler must properly detect the presence type, update the user's roster,
 * and inform presence subscribers of the session's updated presence
 * status. Presence serves many purposes in Jabber so this handler will
 * likely be the most complex of all handlers in the server.
 * <p/>
 * There are four basic types of presence updates:
 * <ul>
 * <li>Simple presence updates - addressed to the server (or to address), these updates
 * are properly addressed by the server, and multicast to
 * interested subscribers on the user's roster. An empty, missing,
 * or "unavailable" type attribute indicates a simple update (there
 * is no "available" type although it should be accepted by the server.
 * <li>Directed presence updates - addressed to particular jabber entities,
 * these presence updates are properly addressed and directly delivered
 * to the entity without broadcast to roster subscribers. Any update type
 * is possible except those reserved for subscription requests.
 * <li>Subscription requests - these updates request presence subscription
 * status changes. Such requests always affect the roster.  The server must:
 * <ul>
 * <li>update the roster with the proper subscriber info
 * <li>push the roster changes to the user
 * <li>forward the update to the correct parties.
 * </ul>
 * The valid types include "subscribe", "subscribed", "unsubscribed",
 * and "unsubscribe".
 * <li>XMPPServer probes - Provides a mechanism for servers to query the presence
 * status of users on another server. This allows users to immediately
 * know the presence status of users when they come online rather than way
 * for a presence update broadcast from the other server or tracking them
 * as they are received.  Requires S2S capabilities.
 * </ul>
 *
 * @author Iain Shigeoka
 */
public class PresenceUpdateHandler extends BasicModule implements ChannelHandler {

    private Map<String, WeakHashMap<ChannelHandler, Set<String>>> directedPresences;

    private RosterManager rosterManager;
    private XMPPServer localServer;
    private PresenceManager presenceManager;
    private PacketDeliverer deliverer;
    private OfflineMessageStore messageStore;
    private SessionManager sessionManager;
    private UserManager userManager;

    public PresenceUpdateHandler() {
        super("Presence update handler");
        directedPresences = new ConcurrentHashMap<String, WeakHashMap<ChannelHandler, Set<String>>>();
    }

    public void process(Packet xmppPacket) throws UnauthorizedException, PacketException {
        Presence presence = (Presence)xmppPacket;
        try {
            ClientSession session = sessionManager.getSession(presence.getFrom());
            Presence.Type type = presence.getType();
            // Available
            if (type == null) {
                if (session != null && session.getStatus() == Session.STATUS_CLOSED) {
                    Log.warn("Rejected available presence: " + presence + " - " + session);
                    return;
                }
                broadcastUpdate(presence.createCopy());
                if (session != null) {
                    session.setPresence(presence);
                    if (!session.isInitialized()) {
                        initSession(session);
                        session.setInitialized(true);
                    }
                }
                // Notify the presence manager that the user is now available. The manager may
                // remove the last presence status sent by the user when he went offline.
                presenceManager.userAvailable(presence);
            }
            else if (Presence.Type.unavailable == type) {
                broadcastUpdate(presence.createCopy());
                broadcastUnavailableForDirectedPresences(presence);
                if (session == null) {
                    // Recovery logic. Check if a session can be found in the routing table.
                    session = (ClientSession) XMPPServer.getInstance().getRoutingTable()
                            .getRoute(presence.getFrom());
                }
                if (session != null) {
                    session.setPresence(presence);
                }
                // Notify the presence manager that the user is now unavailable. The manager may
                // save the last presence status sent by the user and keep track when the user
                // went offline.
                presenceManager.userUnavailable(presence);
            }
            else {
                presence = presence.createCopy();
                if (session != null) {
                    presence.setFrom(new JID(null, session.getServerName(), null));
                    presence.setTo(session.getAddress());
                }
                else {
                    JID sender = presence.getFrom();
                    presence.setFrom(presence.getTo());
                    presence.setTo(sender);
                }
                presence.setError(PacketError.Condition.bad_request);
                deliverer.deliver(presence);
            }

        }
        catch (Exception e) {
            Log.error(LocaleUtils.getLocalizedString("admin.error") + ". Triggered by packet: " +
                    xmppPacket, e);
        }
    }

    /**
     * Handle presence updates that affect roster subscriptions.
     *
     * @param presence The presence presence to handle
     */
    public void process(Presence presence) throws PacketException {
        try {
            process((Packet)presence);
        }
        catch (UnauthorizedException e) {
            try {
                Session session = sessionManager.getSession(presence.getFrom());
                presence = presence.createCopy();
                if (session != null) {
                    presence.setFrom(new JID(null, session.getServerName(), null));
                    presence.setTo(session.getAddress());
                }
                else {
                    JID sender = presence.getFrom();
                    presence.setFrom(presence.getTo());
                    presence.setTo(sender);
                }
                presence.setError(PacketError.Condition.not_authorized);
                deliverer.deliver(presence);
            }
            catch (Exception err) {
                Log.error(LocaleUtils.getLocalizedString("admin.error"), err);
            }
        }
    }

    /**
     * A session that has transitioned to available status must be initialized.
     * This includes:
     * <ul>
     * <li>Sending all offline presence subscription requests</li>
     * <li>Sending offline messages</li>
     * </ul>
     *
     * @param session The session being updated
     * @throws UserNotFoundException If the user being updated does not exist
     */
    private void initSession(ClientSession session)  throws UserNotFoundException {

        // Only user sessions need to be authenticated
        if (userManager.isRegisteredUser(session.getAddress().getNode())) {
            String username = session.getAddress().getNode();

            // Send pending subscription requests to user if roster service is enabled
            if (RosterManager.isRosterServiceEnabled()) {
                Roster roster = rosterManager.getRoster(username);
                for (RosterItem item : roster.getRosterItems()) {
                    if (item.getRecvStatus() == RosterItem.RECV_SUBSCRIBE) {
                        session.process(createSubscribePresence(item.getJid(), true));
                    }
                    else if (item.getRecvStatus() == RosterItem.RECV_UNSUBSCRIBE) {
                        session.process(createSubscribePresence(item.getJid(), false));
                    }
                    if (item.getSubStatus() == RosterItem.SUB_TO
                            || item.getSubStatus() == RosterItem.SUB_BOTH) {
                        presenceManager.probePresence(session.getAddress(), item.getJid());
                    }
                }
            }
            if (session.canFloodOfflineMessages()) {
                // deliver offline messages if any
                Collection<OfflineMessage> messages = messageStore.getMessages(username, true);
                for (Message message : messages) {
                    session.process(message);
                }
            }
        }
    }

    public Presence createSubscribePresence(JID senderAddress, boolean isSubscribe) {
        Presence presence = new Presence();
        presence.setFrom(senderAddress);
        if (isSubscribe) {
            presence.setType(Presence.Type.subscribe);
        }
        else {
            presence.setType(Presence.Type.unsubscribe);
        }
        return presence;
    }

    /**
     * Broadcast the given update to all subscribers. We need to:
     * <ul>
     * <li>Query the roster table for subscribers</li>
     * <li>Iterate through the list and send the update to each subscriber</li>
     * </ul>