CN Vadi

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

public class TCPServer
{

    public static void main (String args[])throws Exception
    {
        String StringFrmClient,StringToClient,capitalized;

        ServerSocket serversocketobj = new ServerSocket(6789pen);
        Socket connectionsocket=serversocketobj.accept();
        BufferedReader InFrmClient= new BufferedReader( new InputStreamReader(connectionsocket.getInputStream()));
        DataOutputStream OutToClient = new DataOutputStream(connectionsocket.getOutputStream());

        while(true)
        {
            StringFrmClient = InFrmClient.readLine();
            capitalized = StringFrmClient.toUpperCase();
            OutToClient.writeBytes(capitalized);
        }
    }
}