Network Protocol Java

import java.io.BufferedReader;
import java.io.BufferedWriter;
import java.io.InputStreamReader;
import java.io.OutputStreamWriter;
import java.io.PrintWriter;
import java.net.InetAddress;
import java.net.Socket;
public class Main {
  public static void main(String[] arges) throws Exception {
    InetAddress addr = InetAddress.getByName(null);
    Socket sk = new Socket(addr, 8888);
    BufferedReader in = new BufferedReader(new InputStreamReader(sk.getInputStream()));
    PrintWriter out = new PrintWriter(new BufferedWriter(new OutputStreamWriter(sk.getOutputStream())), true);
    out.println("asdf");
    System.out.println(in.readLine());
  }
}