/**
   @version 1.20 2004-08-03
   @author Cay Horstmann
*/

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

/**
   This program implements a simple server that listens to port 8189 and echoes back all 
   client input.
*/
public class EchoServer
{  
   public static void main(String[] args )
   {  
      try
      {  
         // establish server socket
         ServerSocket s = new ServerSocket(8189);

         // wait for client connection         
         Socket incoming = s.accept( );
         try
         {
            InputStream inStream = incoming.getInputStream();
            OutputStream outStream = incoming.getOutputStream();

            Scanner in = new Scanner(inStream);         
            PrintWriter out = new PrintWriter(outStream, true /* autoFlush */);

            out.println( "Hello! Enter BYE to exit." );
            
            // echo client input
            boolean done = false;
            while (!done && in.hasNextLine())
            {  
               String line = in.nextLine();            
               out.println("Echo: " + line);            
               if (line.trim().equals("BYE"))
                  done = true;
            }
         }
         finally
         {
            incoming.close();
         }
      }
      catch (IOException e)
      {  
         e.printStackTrace();
      }
   }
}