Socket

import java.io.*;
import java.net.*;

public class SocketExample {
    public static void main(String[] args) {
        String hostName = "localhost";
        int portNumber = 12345;

        try {
            Socket echoSocket = new Socket(hostName, portNumber);
            PrintWriter out = new PrintWriter(echoSocket.getOutputStream(),
                    true);
            BufferedReader in = new BufferedReader(new InputStreamReader(
                    echoSocket.getInputStream()));
            BufferedReader stdIn = new BufferedReader(new InputStreamReader(
                    System.in));
            while (true) {
                String s = in.readLine();
                System.err.println(s);
                out.println(s + " :)");
            }
        } catch (Exception e) {
            e.printStackTrace();
        }
    }
}