為什么此node.js tcp服務器在關閉之前不回寫Java客戶端？

Question

這是我發現用node.js編寫的tcp服務器的示例：

net.createServer(function(sock) {

    // We have a connection - a socket object is assigned to the connection automatically
    console.log('CONNECTED: ' + sock.remoteAddress +':'+ sock.remotePort);

    // Add a 'data' event handler to this instance of socket
    sock.on('data', function(data) {

        console.log('DATA ' + sock.remoteAddress + ': ' + data);
        // Write the data back to the socket, the client will receive it as data from the server
        sock.write('You said "' + data + '"');

    });

    // Add a 'close' event handler to this instance of socket
    sock.on('close', function(data) {
        console.log('CLOSED: ' + sock.remoteAddress +' '+ sock.remotePort);
    });

}).listen(PORT, HOST);

console.log('Server listening on ' + HOST +':'+ PORT);

我試圖以此為基礎的tcp服務器，它將必須同時處理多個傳入連接。 這是我編寫的Java程序來對此進行測試：

public static final String MESSAGE = "Hellow world";
    public static Semaphore networkLock;

    public static void main(String[] args) 
    {
        //writeMessage(MESSAGE);

        Thread[] threadPool = new Thread[10];
        networkLock = new Semaphore(1);

        for (int i = 0; i < threadPool.length; i++) 
        {
            threadPool[i] = new Thread(new Runnable() {

                @Override
                public void run() {
                    writeMessage(MESSAGE);

                }
            });

            threadPool[i].start();
        }

    }

    public static void writeMessage(String test)
    {
        try {
            if(sock == null || sock.isClosed())
                sock = new Socket(HOST, PORT);

            DataOutputStream out =
                    new DataOutputStream(sock.getOutputStream());
            System.out.println("Writting message");

            //networkLock.acquire();
            out.writeUTF(test);
            //networkLock.release();

              BufferedReader in = new BufferedReader(
                        new InputStreamReader(sock.getInputStream()));

              System.out.println("Waiting for reply");
              String input = in.readLine();

              System.out.println(input);
//            in.close();
//          out.close();
//          sock.close();

        } catch (UnknownHostException e) {
            // TODO Auto-generated catch block
            e.printStackTrace();
        } catch (IOException e) {
            // TODO Auto-generated catch block
            e.printStackTrace();
        } 
    }

啟動客戶端時，從客戶端獲得的唯一輸出是很多次的“寫消息”和“等待回復”。 當我關閉服務器時，我終於收到您說“ Hellow world”的響應，並且通常會插入一兩個空值。 至於服務器，它可以很好地打印出兩個打印語句。 您認為有人可以在這里幫助我嗎？

Answer 1

Java客戶端使用in.readLine()在輸入流中查找換行符。 但是，服務器沒有將換行符寫入客戶端套接字。

所以改變這個：

sock.write('You said "' + data + '"');

對此：

sock.write('You said "' + data + '"\n');