Jive Messenger 源码研究

  Jive Messenger 源码研究

第一部分 Jabber Server工作原理和流程

1)Server的启动

通过下面图片来做一个简单的了解

 

1.       按 Launcher(GUI) 是 Jive Messenger Server 启动和停止的可视化界面 ,

按下 Start 键 Server 开始启动

注 :[org.jivesoftware.messenger.launcher.Launcher] 调用 ServerStarter.start()

2.       [org.jivesoftware.messenger.starter.ServerStarter] 加载 lib 库文件 , 同时启动一个

[org.jivesoftware.messenger.XMPPServer] 实体

Class containerClass = loader.loadClass("org.jivesoftware.messenger.XMPPServer"); containerClass.newInstance();

 

3.       XMPPServer 加载模块 (Modules), 组件 (Component), 插件 (Plugin)

public void start() {         try {             initialize();               // If the server has already been setup then we can start all the server's modules             if (!setupMode) {                 verifyDataSource();                 // First load all the modules so that modules may access other modules while                 // being initialized                 loadModules() ;                 // Initize all the modules                 initModules();                 // Start all the modules                 startModules();             }            // Load plugins. First, initialize component manager.             InternalComponentManager.getInstance().start();             File pluginDir = new File(messengerHome, "plugins");             pluginManager = new PluginManager(pluginDir);             pluginManager.start();             …….         }         catch (Exception e) {             …..             shutdownServer();         }     }

下面我们来看一下服务器加载了那些 Module(Component,Plugin 也是非常重要的我将在以后的文章中做讨论 )

private void loadModules() {         // Load boot modules         loadModule(RoutingTableImpl.class.getName());         loadModule(AuditManagerImpl.class.getName());         loadModule(RosterManager.class.getName());         loadModule(PrivateStorage.class.getName());         // Load core modules         loadModule(PresenceManagerImpl.class.getName());         loadModule(SessionManager.class.getName());         loadModule(PacketRouter.class.getName());         loadModule(IQRouter.class.getName());         loadModule(MessageRouter.class.getName());         loadModule(PresenceRouter.class.getName());         loadModule(PacketTransporterImpl.class.getName());         loadModule(PacketDelivererImpl.class.getName());         loadModule(TransportHandler.class.getName());         loadModule(OfflineMessageStrategy.class.getName());         loadModule(OfflineMessageStore.class.getName());         // Load standard modules         loadModule(IQAuthHandler.class.getName());         loadModule(IQPrivateHandler.class.getName());         loadModule(IQRegisterHandler.class.getName());         loadModule(IQRosterHandler.class.getName());         loadModule(IQTimeHandler.class.getName());         loadModule(IQvCardHandler.class.getName());         loadModule(IQVersionHandler.class.getName());         loadModule(IQLastActivityHandler.class.getName());         loadModule(PresenceSubscribeHandler.class.getName());         loadModule(PresenceUpdateHandler.class.getName());         loadModule(IQDiscoInfoHandler.class.getName());         loadModule(IQDiscoItemsHandler.class.getName());         loadModule(IQOfflineMessagesHandler.class.getName());         loadModule(MultiUserChatServerImpl.class.getName());         loadModule(MulticastDNSService.class.getName());         // Load this module always last since we don't want to start listening for clients         // before the rest of the modules have been started         loadModule(ConnectionManagerImpl.class.getName());     }

Server 启动的时候加载的模块非常多 , 其中最后一个加载的 ConnectionManagerImpl 它是 ConnectionManager 接口的实现 , 用来负责管理用户 (jabberClient) 连接

 

另外所有模块都是继承 (extends) 了 BasicModule 或者实现 (implements) 了 Module

4. ConnectionManageImpl 启动

public void start() {         super.start();         isStarted = true;         serverName = server.getServerInfo().getName();         createSocket();         SocketSendingTracker.getInstance().start();     }

Start 方法创建 Socket( 监听客户端的连接 ), 并启动一个 SocketSendingTracker 线程 , 用来检查 Socket 是否正常连接

5.JabberServer 启动完成

2) 客户端连接 , 待续

 

2 ） Client 和 Server 交互流程

1 ．   客户端启动一个 XMPPConnection 和 Server 建立 Socket 的连接

2 ．   用户通过 PacketWriter 发 IQ 给 Server ，服务器 ClientSocketReader 接受到这个 IQ ，对用户登陆进行认证

3 ．   当 ClientA 发 Packet 给 ClientB 的 ClientSocketReader 会调用 PacketRouter 把 Packet 转发给 ClientB （现在先不太 Server2Server 的情况）

Jive Messenger Server 如何创建 Session （代码分析）

 

 

ConnectionManagerImpl 初始化（

//ConnectionManagerImpl.java public void initialize(XMPPServer server) {         super.initialize(server);         this.server = server;         router = server.getPacketRouter();         deliverer = server.getPacketDeliverer();         sessionManager = server.getSessionManager();     }

ConnectionManagerImpl 启动

//ConnectionManagerImpl.java public void start() {         super.start();         isStarted = true;         serverName = server.getServerInfo().getName();         createSocket();         SocketSendingTracker.getInstance().start();     }

ConnectionManagerImpl 创建 Socket

//ConnectionManagerImpl.java private void createSocket() {         ……         // Start the port listener for s2s communication         startServerListener(localIPAddress);         // Start the port listener for external components         startComponentListener(localIPAddress);         // Start the port listener for clients         startClientListeners(localIPAddress);         // Start the port listener for secured clients         startClientSSLListeners(localIPAddress);     }

ConnectionManagerImpl 开启 socket 监听，启动 SocketAcceptTread 线程

//ConnectionManagerImpl.java private void startClientListeners(String localIPAddress) {             ……             try {                 socketThread = new SocketAcceptThread (this, serverPort);                 ports.add(serverPort);                 socketThread.setDaemon(true);                 socketThread.start();                 ……             }             catch (Exception e) {                …..             }         }     }

SocketAcceptTread 启动过程

// SocketAcceptTread.java public void run() {         while (notTerminated) {             try {                 Socket sock = serverSocket.accept();                 if (sock != null) {                     Log.debug("Connect " + sock.toString());                     connManager.addSocket(sock, false, serverPort);                 }             }             catch (IOException ie) {               …..                 }                      …..         }      // 线程结束的时候后面处理关闭 serverSocket      ……     }

当一个 Client 连接到 Server,ConnectionManagerImpl 增加一个 Socket 连接

//ConnectionManagerImpl.java public void addSocket(Socket sock , boolean isSecure, ServerPort serverPort) {         try {             SocketConnection conn = new SocketConnection(deliverer, sock , isSecure);             SocketReader reader = null;             String threadName = null;             if (serverPort.isClientPort()) {                 reader = new ClientSocketReader(router, serverName, sock , conn );                 threadName = "Client SR";             }             else if (serverPort.isComponentPort()) {                 reader = new ComponentSocketReader(router, serverName, sock, conn);                 threadName = "Component SR";             }             else {                 reader = new ServerSocketReader(router, serverName, sock, conn);                 threadName = "Server SR";             }             Thread thread = new Thread(reader, threadName);              thread.setDaemon(true);             thread.start();         }         catch (IOException e) {             Log.error(LocaleUtils.getLocalizedString("admin.error"), e);         }     }

ConnectionManagerImpl 启动一个 SocketReader 线程

//SocketReader.java public void run() {         try {             reader = new XPPPacketReader();             reader.setXPPFactory(factory);             reader.getXPPParser().setInput(new InputStreamReader(socket.getInputStream(),                     CHARSET));             // Read in the opening tag and prepare for packet stream             try {                 //socketReader 启动的时，需要创建一个 Session 来负责和 Client 的会话                 createSession();             }             catch (IOException e) {                 …..             }             // 会话结束后的处理             if (session != null) {                 readStream();             }           }         catch (EOFException eof) {             // Normal disconnect         }            }

createSession() 调用 abstract 方法 createSession(String namespace) ，这个方法的在不同客户端的 SocketReader 中被实现，我们拿 ClientSocketReader 举例

//ClientSocketReader.java Boolean createSession(String namespace) …{         if ("jabber:client".equals(namespace)) {             // ClientSession 负责创建一个 ClientSession             session = ClientSession.createSession(serverName, reader, connection);             return true;         }         return false;     }

 ClientSeesion 创建 ClientSeesion 的过程

//ClientSeesion.java public static Session createSession(String serverName, XPPPacketReader reader,             SocketConnection connection) throws XmlPullParserException, UnauthorizedException,IOException{         ……         // 为用户创建一个 Session         Session session = SessionManager.getInstance().createClientSession(connection);         Writer writer = connection.getWriter();         // 创建 packet response 的开头         ……             boolean done = false;         while (!done) {             if (xpp.next() == XmlPullParser.START_TAG) {                 done = true;                 if (xpp.getName().equals("starttls") &&                         xpp.getNamespace(xpp.getPrefix()).equals(TLS_NAMESPACE))                 {                     writer.write("");                     if (isFlashClient) {                         writer.write('/0');                     }                     writer.flush();                     // TODO: setup SSLEngine and negotiate TLS.                 }             }         }           return session;}

//SessionManager.java public Session createClientSession(Connection conn) throws UnauthorizedException {         if (serverName == null) {             throw new UnauthorizedException("Server not initialized");         }         StreamID id = nextStreamID();         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().toString(), session);         return session;     }

 

总结一下：

1 ．  ConnectionManagermentImpl 初始化启动

2 ．  ConnectionManagermentImpl 创建一个 Socket 启动监听

3 ．   当客户端启动 Socket 连接， SocketAcceptThread 接受客户端连接

ConnectionManagerImpl 调用 addSocket ，创建一个 SocketConnection 和 SocketReader ，并启动 SocketReader 线程

4 ．  SocketReader 会创建一个用户会话（ Session ）