============================================================
File Name: MyClient.java
============================================================
import java.io.*;
import java.net.*;

public class MyClient {
public static void main(String[] args) {
try{	
Socket s=new Socket("localhost",6666);
	
DataOutputStream dout=new DataOutputStream(s.getOutputStream());

dout.writeUTF("Hello Server");
dout.flush();

dout.close();
s.close();

}catch(Exception e){System.out.println(e);}
}
}



============================================================
File Name: MyServer.java
============================================================
import java.io.*;
import java.net.*;

public class MyServer {
public static void main(String[] args){
try{
ServerSocket ss=new ServerSocket(6666);
Socket s=ss.accept();//establishes connection 

DataInputStream dis=new DataInputStream(s.getInputStream());

String	str=(String)dis.readUTF();
System.out.println("message= "+str);

ss.close();

}catch(Exception e){System.out.println(e);}
}
}




Note:  Compile both program first than run both program in two different cmd