Chương trình sau thực hiện công việc gì? for (int i = 0; i < args.length; i++) { try { Socket socket = new Socket(args[i], 80); System.out.print("Connected to " + socket.getInetAddress()); System.out.print(" on port " + socket.getPort()); System.out.print(" from port " + socket.getLocalPort()); System.out.println(" of " + socket.getLocalAddress()); } catch(UnknownHostException e) { e.printStackTrace(); } catch(SocketException e) { e.printStackTrace(); } catch(IOException e) { e.printStackTrace(); }