Viết chương trình truyền dữ liệu giữa 2 máy (5)

  protected DataInputStream i;
  protected DataOutputStream o;

  protected TextArea output;
  protected TextField input;

  protected Thread listener;

  public ChatClient (String title, InputStream i, OutputStream o) {
  super (title);
  this.i = new DataInputStream (new BufferedInputStream (i));
  this.o = new DataOutputStream (new BufferedOutputStream (o));
  setLayout (new BorderLayout ());
  add ("Center", output = new TextArea ());
  output.setEditable (false);
  add ("South", input = new TextField ());
  pack ();
  show ();
  input.requestFocus ();
  listener = new Thread (this);
  listener.start ();
  }

public void run () {
  try {
  while (true) {
  String line = i.readUTF ();
  output.appendText (line + "\n");
  }
  } catch (IOException ex) {
  ex.printStackTrace ();
  } finally {
  listener = null;
  input.hide ();
  validate ();
  try {
  o.close ();
  } catch (IOException ex) {
  ex.printStackTrace ();
  }
  }
  }

public boolean handleEvent (Event e) {
  if ((e.target == input) && (e.id == Event.ACTION_EVENT)) {
  try {
  o.writeUTF ((String) e.arg);
  o.flush ();
  } catch (IOException ex) {
  ex.printStackTrace();
  listener.stop ();
  }
  input.setText ("");
  return true;
  } else if ((e.target == this) && (e.id == Event.WINDOW_DESTROY)) {
  if (listener != null)
  listener.stop ();
  hide ();
  return true;
  }
  return super.handleEvent (e);
  }

public static void main (String args[]) throws IOException {
  if (args.length != 2)
  throw new RuntimeException ("Syntax: ChatClient ");

  Socket s = new Socket (args[0], Integer.parseInt (args[1]));
  new ChatClient ("Chat " + args[0] + ":" + args[1],
  s.getInputStream (), s.getOutputStream ());
  }

  public ChatServer (int port) throws IOException {
  ServerSocket server = new ServerSocket (port);
  while (true) {
  Socket client = server.accept ();
  System.out.println ("Accepted from " + client.getInetAddress ());
  ChatHandler c = new ChatHandler (client);
  c.start ();
  }
  }

public static void main (String args[]) throws IOException {
  if (args.length != 1)
  throw new RuntimeException ("Syntax: ChatServer ");
  new ChatServer (Integer.parseInt (args[0]));
  }

The main() method creates an instance of the ChatServer, passing the command-line port as a parameter. This is the port to which clients will connect.