import java.io.*;
import java.net.*;
/**
   This program implements a simple server that listens to
   PORT and echoes back all client input.
   $ java TCP_EchoServer
*/
public class TCP_EchoServer {  
   public static final int PORT = 47200;
   public static void main(String[] args ) {  
      try {  
         // establish server socket
         ServerSocket s = new ServerSocket(PORT);
         System.out.println("Started: " + s);
         // wait for client connection
         Socket incoming = s.accept( );
         System.out.println("Connection accepted: "+ incoming);
         BufferedReader in = new BufferedReader(new InputStreamReader(incoming.getInputStream()));
         PrintWriter out = new PrintWriter(incoming.getOutputStream(), true /* autoFlush */);
         // echo client input
         boolean done = false;
         while (!done) {  
            String line = in.readLine();
            if (line == null) done = true;
            else {  
               out.println("Echo: " + line);
               if (line.trim().equals("BYE"))
                  done = true;
            }
         }
         incoming.close();
      } catch (Exception e) {  
         e.printStackTrace();
      }
   }
}