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

class ServeOneEcho extends Thread {
  private Socket socket;
  private BufferedReader in;
  private PrintWriter out;
  public ServeOneEcho(Socket s) 
      throws IOException {
    socket = s;
    in = 
      new BufferedReader( new InputStreamReader( socket.getInputStream()));
    // Enable auto-flush:
    out = new PrintWriter( new BufferedWriter( new OutputStreamWriter(
            socket.getOutputStream())), true);
    start(); // Calls run()
  }
  public void run() {
    try {
      while (true) {  
        String str = in.readLine();
        if (str.equals("END")) break;
        System.out.println("Echoing: " + str);
        out.println(str);
      }
      System.out.println("closing...");
    } catch(IOException e) {
      System.err.println("IO Exception");
    } finally {
      try {
        socket.close();
      } catch(IOException e) {
        System.err.println("Socket not closed");
      }
    }
  }
}

public class MultiEchoServer {  
  public static void main(String[] args)
      throws IOException {
    ServerSocket s = new ServerSocket(0);
    String ServerPort = s.getLocalPort()+"\n";

    System.out.println("Server Started at Port: " + ServerPort);
    try {
      while(true) {
        // Blocks until a connection occurs:
        Socket socket = s.accept();
        try {
          new ServeOneEcho (socket);
        } catch(IOException e) {
          socket.close();
        }
      }
    } finally {
      s.close();
    }
  } 
}