为什么服务器没有看到客户端发送数据？

Question

为什么serverSocket.accept（）什么都没发生？服务器从客户端获取数据，但是programm对方法serverSocket.accept（）什么都不做

public void start() {
        try {
            Socket socket= serverSocket.accept();
            System.out.println("Client accepted");

            in = new DataInputStream(
                    new BufferedInputStream(socket.getInputStream()));
            String line = "";
                    try {
                    line = in.readUTF();
                    System.out.println(line);

                } catch (IOException i) {
                    System.out.println(i);
                }
        } catch (IOException e) {
            System.out.println(e);
        }
    }

Answer 1

serverSocket.accept();

阻塞直到连接套接字。

Socket s = serverSocket.accept();

in = new DataInputStream(new BufferedInputStream(s.getInputStream()));

要么

socket = serverSocket.accept();
in = new DataInputStream(new BufferedInputStream(socket.getInputStream()));

编辑 - 29.03.2019 11.54

所以我们知道：

serverSocket.accept();

阻止你的线程。你在主线程中调用它。

...
successfulThreads = new AtomicInteger(0);
latch = new CountDownLatch(testcaseThreads);
gate = new CyclicBarrier(testcaseThreads + 1);

server = new Server(SOCKET_PORT);
server.start();  //<-- Your program blocks!!!
//  ||
//  || STOP! No execution of the code.
// \\//
//  \/
for (File testcaseFile : testcaseFiles) {
            new Thread(new MockClient(this, testcaseFile)).start();
}