sessionmanager.java

基于Jabber协议的即时消息服务器

        /**
         * Add a session to the manager.
         *
         * @param session
         */
        void addSession(ClientSession session) {
            String resource = session.getAddress().getResource();
            Presence presence = session.getPresence();
            int priority = presence == null ? 0 : presence.getPriority();
            resources.put(resource, session);
            sortSession(resource, priority);
        }

        /**
         * Sorts the session into the list based on priority
         *
         * @param resource The resource corresponding to the session to sort
         * @param priority The priority to use for sorting
         */
        private void sortSession(String resource, int priority) {
            synchronized (priorityList) {
                if (priorityList.size() > 0) {
                    Iterator<String> iter = priorityList.iterator();
                    for (int i = 0; iter.hasNext(); i++) {
                        ClientSession sess = resources.get(iter.next());
                        if (sess != null && sess.getPresence().getPriority() <= priority) {
                            priorityList.add(i, resource);
                            break;
                        }
                    }
                }
                if (!priorityList.contains(resource)) {
                    priorityList.addLast(resource);
                }
            }
        }

        /**
         * Change the priority of a session associated with the sender.
         *
         * @param sender   The sender who's session just changed priority
         * @param priority The new priority for the session
         */
        public void changePriority(JID sender, int priority) {
            String resource = sender.getResource();
            if (resources.containsKey(resource)) {
                synchronized (priorityList) {
                    priorityList.remove(resource);
                    sortSession(resource, priority);
                }
            }
        }

        /**
         * Remove a session from the manager.
         *
         * @param session The session to remove.
         * @return true if the session was present in the map and was removed.
         */
        boolean removeSession(Session session) {
            String resource = session.getAddress().getResource();
            boolean removed = resources.remove(resource) != null;
            synchronized (priorityList) {
                priorityList.remove(resource);
            }
            return removed;
        }

        /**
         * Gets the session for the given resource.
         *
         * @param resource The resource describing the particular session
         * @return The session for that resource or null if none found (use getDefaultSession() to obtain default)
         */
        ClientSession getSession(String resource) {
            return resources.get(resource);
        }

        /**
         * Checks to see if a session for the given resource exists.
         *
         * @param resource The resource of the session we're checking
         * @return True if we have a session corresponding to that resource
         */
        boolean hasSession(String resource) {
            return resources.containsKey(resource);
        }

        /**
         * Returns the default session for the user based on presence priority. It's possible to
         * indicate if only available sessions (i.e. with an available presence) should be
         * included in the search.
         *
         * @param filterAvailable flag that indicates if only available sessions should be
         *        considered.
         * @return The default session for the user.
         */
        ClientSession getDefaultSession(boolean filterAvailable) {
            if (priorityList.isEmpty()) {
                return null;
            }

            if (!filterAvailable) {
                return resources.get(priorityList.getFirst());
            }
            else {
                synchronized (priorityList) {
                    for (int i=0; i < priorityList.size(); i++) {
                        ClientSession s = resources.get(priorityList.get(i));
                        if (s != null && s.getPresence().isAvailable()) {
                            return s;
                        }
                    }
                }
                return null;
            }
        }

        /**
         * Determines if this map is empty or not.
         *
         * @return True if the map contains no entries
         */
        boolean isEmpty() {
            return resources.isEmpty();
        }

        /**
         * Broadcast to all resources for the given user
         *
         * @param packet
         */
        private void broadcast(Packet packet) throws UnauthorizedException, PacketException {
            for (Session session : resources.values()) {
                packet.setTo(session.getAddress());
                session.process(packet);
            }
        }

        /**
         * Create an iterator over all sessions for the user.
         * We create a new list to generate the iterator so other threads
         * may safely alter the session map without affecting the iterator.
         *
         * @return An iterator of all sessions
         */
        public Collection<ClientSession> getSessions() {
            return resources.values();
        }

        /**
         * Returns a collection of all the sessions whose presence is available.
         *
         * @return a collection of all the sessions whose presence is available.
         */
        public Collection<ClientSession> getAvailableSessions() {
            LinkedList<ClientSession> list = new LinkedList<ClientSession>();
            for (ClientSession session : resources.values()) {
                if (session.getPresence().isAvailable()) {
                    list.add(session);
                }
            }
            return list;
        }

        /**
         * This specified session has received an available presence so we need to recalculate the
         * order of the sessions so we can have update the default session.
         *
         * @param session the session that received an available presence.
         */
        public void sessionAvailable(ClientSession session) {
            changePriority(session.getAddress(), session.getPresence().getPriority());
        }

        /**
         * This specified session has received an unavailable presence so we need to recalculate the
         * order of the sessions so we can have update the default session.
         *
         * @param session the session that received an unavailable presence.
         */
        public void sessionUnavailable(ClientSession session) {
            changePriority(session.getAddress(), 0);
        }
    }

    /**
     * Returns a randomly created ID to be used in a stream element.
     *
     * @return a randomly created ID to be used in a stream element.
     */
    public StreamID nextStreamID() {
        return streamIDFactory.createStreamID();
    }

    /**
     * Creates a new <tt>ClientSession</tt>. The new Client session will have a newly created
     * stream ID.
     *
     * @param conn the connection to create the session from.
     * @return a newly created session.
     * @throws UnauthorizedException
     */
    public ClientSession createClientSession(Connection conn) throws UnauthorizedException {
        return createClientSession(conn, nextStreamID());
    }

    /**
     * Creates a new <tt>ClientSession</tt> with the specified streamID.
     *
     * @param conn the connection to create the session from.
     * @param id the streamID to use for the new session.
     * @return a newly created session.
     * @throws UnauthorizedException
     */
    public ClientSession createClientSession(Connection conn, StreamID id)
            throws UnauthorizedException {
        if (serverName == null) {
            throw new UnauthorizedException("Server not initialized");
        }
        ClientSession session = new ClientSession(serverName, conn, id);
        conn.init(session);
        // Register to receive close notification on this session so we can
        // remove  and also send an unavailable presence if it wasn't
        // sent before
        conn.registerCloseListener(clientSessionListener, session);

        // Add to pre-authenticated sessions.
        preAuthenticatedSessions.put(session.getAddress().getResource(), session);
        // Increment the counter of user sessions
        usersSessionsCounter.incrementAndGet();
        return session;
    }

    public Session createComponentSession(Connection conn) throws UnauthorizedException {
        if (serverName == null) {
            throw new UnauthorizedException("Server not initialized");
        }
        StreamID id = nextStreamID();
        ComponentSession session = new ComponentSession(serverName, conn, id);
        conn.init(session);
        // Register to receive close notification on this session so we can
        // remove the external component from the list of components
        conn.registerCloseListener(componentSessionListener, session);

        // Add to component session.
        componentsSessions.add(session);
        return session;
    }

    /**
     * Creates a session for a remote server. The session should be created only after the
     * remote server has been authenticated either using "server dialback" or SASL.
     *
     * @param conn the connection to the remote server.
     * @param id the stream ID used in the stream element when authenticating the server.
     * @return the newly created {@link IncomingServerSession}.
     * @throws UnauthorizedException if the local server has not been initialized yet.
     */
    public IncomingServerSession createIncomingServerSession(Connection conn, StreamID id)
            throws UnauthorizedException {
        if (serverName == null) {
            throw new UnauthorizedException("Server not initialized");
        }
        IncomingServerSession session = new IncomingServerSession(serverName, conn, id);
        conn.init(session);
        // Register to receive close notification on this session so we can
        // remove its route from the sessions set
        conn.registerCloseListener(incomingServerListener, session);

        return session;
    }

    /**
     * Notification message that a new OutgoingServerSession has been created. Register a listener
     * that will react when the connection gets closed.
     *
     * @param session the newly created OutgoingServerSession.
     */
    public void outgoingServerSessionCreated(OutgoingServerSession session) {
        // Register to receive close notification on this session so we can
        // remove its route from the sessions set
        session.getConnection().registerCloseListener(outgoingServerListener, session);
    }

    /**
     * Registers that a server session originated by a remote server is hosting a given hostname.
     * Notice that the remote server may be hosting several subdomains as well as virtual hosts so
     * the same IncomingServerSession may be associated with many keys. If the remote server
     * creates many sessions to this server (eg. one for each subdomain) then associate all
     * the sessions with the originating server that created all the sessions.
     *
     * @param hostname the hostname that is being served by the remote server.
     * @param session the incoming server session to the remote server.
     */
    public void registerIncomingServerSession(String hostname, IncomingServerSession session) {
        synchronized (incomingServerSessions) {
            List<IncomingServerSession> sessions = incomingServerSessions.get(hostname);
            if (sessions == null || sessions.isEmpty()) {
                // First session from the remote server to this server so create a
                // new association
                List<IncomingServerSession> value = new CopyOnWriteArrayList<IncomingServerSession>();
                value.add(session);
                incomingServerSessions.put(hostname, value);
            }
            else {
                // Add new session to the existing list of sessions originated by