Something wrong with my socket program - sockets

Question

I wrote a program communicated with sockets.But I don't know why they don't work.
Server Code:
this.serverSocket = new ServerSocket(ServerConnector.port);
this.socketListener = this.serverSocket.accept();
System.out.println(this.socketListener.getPort());
this.objIn = new ObjectInputStream(this.socketListener.getInputStream());
System.out.println("1");
this.objOut = new ObjectOutputStream(this.socketListener.getOutputStream());
System.out.println("1");
this.objOut.writeInt(19999);
System.out.println("1");
this.objOut.writeObject(new Date());
System.out.println("1");
Client Code:
this.clientSocket = new Socket(ClientConnector.host, ClientConnector.port);
System.out.println(this.clientSocket.getPort());
this.objIn = new ObjectInputStream(this.clientSocket.getInputStream());
System.out.println("1");
this.objOut = new ObjectOutputStream(this.clientSocket.getOutputStream());
System.out.println("1");
int i = (Integer) this.objIn.readInt();
System.out.println(i);
Date date = (Date) this.objIn.readObject();
The truth is, they don't show any information I suggested to pass through(19999 and date), they even can't print a line of "1"(I added for testing). It means even the line below can't work normally. I really confused by these, who can figure the error out?
this.objIn = new ObjectInputStream(this.clientSocket.getInputStream());

Answer 1

You are most likely experiencing the effect of Nagle's Algorithm. which tries to optimize packet sending in TCP. If you want to send your data immediately you need to disable it using the setTcpNoDelay method on the socket interface.
P.S. no idea why the question is tag'ed as osgi, as it has no relevance to OSGi at all.