Подключение по TCP

Попробуй мой отредактированный вариант. Обрати внимание на передаваемые параметры - адрес и порт.

public class Client {
    static Socket socket;
    static DataInputStream in;
    static DataOutputStream out;
    public static void main(String[] ar) {
        String address = ar[0]; //параметрами получаем адрес и порт
        int serverPort = Integer.parseInt(ar[1]); 

        try {
            InetAddress ipAddress = InetAddress.getByName(address); 
            System.out.println("Any of you heard of a socket with IP address " + address + " and port " + serverPort + "?"+ ipAddress);
            socket = new Socket(ipAddress, serverPort); 
            System.out.println("Yes! I just got hold of the program.");

            InputStream sin = socket.getInputStream();
            OutputStream sout = socket.getOutputStream();

            in = new DataInputStream(sin);
            out = new DataOutputStream(sout);

            BufferedReader keyboard = new BufferedReader(new InputStreamReader(System.in));
            String line = null;
            System.out.println("Type in something and press enter. Will send it to the server and tell ya what it thinks.");
            System.out.println();
            while (true) {
                line = keyboard.readLine(); 
                System.out.println("Sending this line to the server...");
                out.writeUTF(line); 
                out.flush(); // заставляем поток закончить передачу данных.
                line = in.readUTF(); 
                System.out.println("The server was very polite. It sent me this : " + line);
                System.out.println("Looks like the server is pleased with us. Go ahead and enter more lines.");
                System.out.println();
            }
        } catch (Exception x) {
            x.printStackTrace();
        } finally {
            try {
                in.close();
                out.close();
                if(socket!=null) {
                    socket.close();
                }
            } catch (IOException e) {
                // TODO Auto-generated catch block
                e.printStackTrace();
            }
            System.out.println("Соединение с портом разорвано разорвано");
        }
    }
}
public class Server {
    static ServerSocket ss;
    public static void main(String[] ar){
        int port = Integer.parseInt(ar[0]); 
        try{
            ss = new ServerSocket(port);
        }catch (IOException e) {
            System.out.println("Порт: "+port+" занят");
            return;
        }

        try {
             System.out.println("Waiting for a client...");
             while(true) {
                 Socket socket = ss.accept(); 
                 System.out.println("Got a client :) ... Finally, someone saw me through all the cover!");
                 System.out.println();

                 InputStream sin = socket.getInputStream();
                 OutputStream sout = socket.getOutputStream();

                 DataInputStream in = new DataInputStream(sin);
                 DataOutputStream out = new DataOutputStream(sout);
                 String line = null;
               line = in.readUTF(); 
               System.out.println("The dumb client just sent me this line : " + line);
               System.out.println("I'm sending it back...");
               out.writeUTF(line); 
               out.flush(); 
               System.out.println("Waiting for the next line...");
               System.out.println();
             }
        } catch(Exception x) { 
            x.printStackTrace();
        } finally {
            try {
                if(ss!=null) {
                ss.close();
                }
            } catch (IOException e) {
                // TODO Auto-generated catch block
                e.printStackTrace();
            }
            System.out.println("Соединение с портом разорвано разорвано");
        }
    }
}