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.
 * @version 1.20 2004年08月03日
 * @author Cay Horstmann
 */
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();
 }
 }
}