Apache Mina實戰

Mina介紹

Mina可以用於快速的開發基於網路通訊的應用，特別是在開發手機端的遊戲應用時，使用的較為普遍。本文簡單介紹了一個用Mina搭建的一個簡易討論組，透過該應用可以對Mina的基本用法用途有個大致的瞭解。

介面效果

介面元素不多，使用了兩個AWT元件。

客戶端1：

客戶端2：

服務端日誌：

核心程式碼

服務端Handler

/**
 * <服務端訊息Handler>
 *
 * @author liping.action@gmail.com
 * @version V1.0
 */
public class ServerMessageHandler extends IoHandlerAdapter {
    private MsgQueue msgQueueReceived;
    private MsgQueue msgQueueSent;

    public MsgQueue getMsgQueueReceived() {
        return msgQueueReceived;
    }

    public void setMsgQueueReceived(MsgQueue msgQueueReceived) {
        this.msgQueueReceived = msgQueueReceived;
    }

    public MsgQueue getMsgQueueSent() {
        return msgQueueSent;
    }

    public void setMsgQueueSent(MsgQueue msgQueueSent) {
        this.msgQueueSent = msgQueueSent;
    }

    static {
        PropertyConfigurator.configure(ClassLoader
                .getSystemResource("log4j.properties"));
    }
    private static Logger logger = Logger.getLogger(ServerMessageHandler.class);

    @Override
    public void exceptionCaught(IoSession session, Throwable cause)
            throws Exception {
        logger.error(cause.toString());
    }

    @Override
    public void messageReceived(IoSession session, Object message)
            throws Exception {
        Msg msg = (Msg) message;
        logger.info("MSG:from=" + session.getRemoteAddress() + ",id="
                + msg.getId() + ",content=" + msg.getContent());
        Collection<IoSession> sessions = session.getService()
                .getManagedSessions().values();
        msg.setId(session.getRemoteAddress().toString());
        for (IoSession ioSession : sessions) {
            ioSession.write(msg);
        }
    }

    @Override
    public void messageSent(IoSession session, Object message) throws Exception {
        logger.info(Constant.MESSAGE_SENT);
    }

    @Override
    public void sessionClosed(IoSession session) throws Exception {
        logger.info(Constant.SESSION_CLOSED);
    }

    @Override
    public void sessionCreated(IoSession session) throws Exception {
        logger.info(Constant.SESSION_CREATED);
    }

    @Override
    public void sessionIdle(IoSession session, IdleStatus status)
            throws Exception {
        logger.info(Constant.SESSION_IDLE);
    }

    @Override
    public void sessionOpened(IoSession session) throws Exception {
        logger.info(Constant.SESSION_OPENED);
        logger.info("address : "
                + session.getRemoteAddress());
    }

}

客戶端handler

/**
 * <客戶端handler>
 *
 * @author liping.action@gmail.com
 * @version V1.0
 */
public class ClientMessageHanlder extends IoHandlerAdapter {
    private static Logger logger = Logger.getLogger(ClientMessageHanlder.class);
    private MsgModel msgModel;

    public MsgModel getMsgModel() {
        return msgModel;
    }

    public void setMsgModel(MsgModel msgModel) {
        this.msgModel = msgModel;
    }

    @Override
    public void exceptionCaught(IoSession session, Throwable cause)
            throws Exception {
        super.exceptionCaught(session, cause);
    }

    @Override
    public void messageReceived(IoSession session, Object message)
            throws Exception {
        Msg msg = (Msg) message;
        logger.info("msg:id=" + msg.getId() + ",content=" + msg.getContent());
        msgModel.setMsg(msg);
        msgModel.fireModelChange();//觸發模型變更，通知觀察者
    }

    @Override
    public void messageSent(IoSession session, Object message) throws Exception {
        super.messageSent(session, message);
    }

    @Override
    public void sessionClosed(IoSession session) throws Exception {
        super.sessionClosed(session);
    }

    @Override
    public void sessionCreated(IoSession session) throws Exception {
        super.sessionCreated(session);
    }

    @Override
    public void sessionIdle(IoSession session, IdleStatus status)
            throws Exception {
        super.sessionIdle(session, status);
    }

    @Override
    public void sessionOpened(IoSession session) throws Exception {
        Msg msg = new Msg(session.getRemoteAddress().toString(),
                session.getLocalAddress() + " " + DateUtil.getCurrentData() + " 進入了討論組！");
        session.write(msg);
    }
}

服務端啟動器：

/**
 * 服務端啟動器
 *
 */
public class ServerLauncher {
    static {
        PropertyConfigurator.configure(ClassLoader
                .getSystemResource("log4j.properties"));
    }
    private static Logger logger = Logger.getLogger(ServerMessageHandler.class);

    public static void main(String[] args) {
        // 建立一個非阻塞的server端Socket ，用NIO
        SocketAcceptor acceptor = new NioSocketAcceptor();
        // 建立接收資料的過濾器
        DefaultIoFilterChainBuilder chain = acceptor.getFilterChain();
        // 設定這個過濾器將以物件為單位讀取資料
        ProtocolCodecFilter filter = new ProtocolCodecFilter(
                new ObjectSerializationCodecFactory());
        chain.addLast("objectFilter", filter);
        // 設定伺服器訊息處理器
        acceptor.setHandler(new ServerMessageHandler());
        // 伺服器繫結的埠
        int bindPort = 9988;
        // 繫結埠，啟動伺服器
        try {
            acceptor.bind(new InetSocketAddress(bindPort));
        } catch (IOException e) {
            logger.error(e.toString());
        }
        logger.info("Mina Server run done! on port:" + bindPort);
    }
}

客戶端啟動器：

/**
 * 客戶端啟動器
 *
 */
public class ClientLauncher {
    static {
        PropertyConfigurator.configure(ClassLoader
                .getSystemResource("log4j.properties"));
    }

    public static void main(String[] args) {
        // 建立訊息模型（被觀察者）
        MsgModel model = new MsgModel();
        // 建立一個tcp/ip 連線
        NioSocketConnector connector = new NioSocketConnector();
        /*---------接收物件---------*/
        // 建立接收資料的過濾器
        DefaultIoFilterChainBuilder chain = connector.getFilterChain();
        // 設定這個過濾器將以物件為單位讀取資料
        ProtocolCodecFilter filter = new ProtocolCodecFilter(
                new ObjectSerializationCodecFactory());
        chain.addLast("objectFilter", filter);
        ClientMessageHanlder hanlder = new ClientMessageHanlder();
        hanlder.setMsgModel(model);
        // 設定客戶端端的訊息處理器
        connector.setHandler(hanlder);
        // Set connect timeout.
        connector.setConnectTimeoutCheckInterval(30);
        // 連結到伺服器:
        final ConnectFuture cf = connector.connect(new InetSocketAddress(
                "127.0.0.1", 9988));
        createComponent(model, cf);
        cf.awaitUninterruptibly();
        cf.getSession().getCloseFuture().awaitUninterruptibly();
        connector.dispose();
    }

    private static void createComponent(MsgModel model, final ConnectFuture cf) {
        JFrame frame = new JFrame("Client");
        frame.setLocation(450, 300);
        final TextField textField = new TextField();

        textField.addKeyListener(new KeyListener() {
            public void keyTyped(KeyEvent arg0) {
            }

            public void keyReleased(KeyEvent arg0) {
            }

            public void keyPressed(KeyEvent arg0) {
                if (arg0.getKeyCode() == KeyEvent.VK_ENTER) {
                    String value = textField.getText();
                    if (!value.equals("")) {
                        Msg msg = new Msg("0002", value);
                        cf.getSession().write(msg);
                        textField.setText("");
                    }
                }
            }
        });
        // 自定義TextArea
        CusTextArea textArea = new CusTextArea();
        model.addObserver(textArea);
        frame.setSize(300, 450);
        frame.setResizable(false);
        frame.setBackground(Color.white);
        frame.add(textField, BorderLayout.SOUTH);
        frame.add(textArea, BorderLayout.NORTH);
        frame.pack();
        frame.setVisible(true);
        frame.addWindowListener(new CloseHandler(cf.getSession()));
        textField.requestFocus();
    }
}

結語

該應用為一個簡單的討論組程式，可實現多人討論，說白了是重複造輪子，但透過此應用可以對mima的用法及原理進行簡單瞭解。程式還有其他程式碼沒有貼上來，全部由三部分組成，服務端、客戶端、公共元件。公共元件提供服務端、客戶端公共使用的部分，如訊息，訊息佇列，訊息模型等。如需要程式原始碼，聯絡我的郵件獲取。

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