//*****
import java.net.Socket;
import java.net.ServerSocket;
import java.io.IOException;
import java.io.BufferedReader;
import java.io.InputStreamReader;
import java.io.PrintWriter;
public class ReverseServerMT {
    public static void main(String[ ] args) {
      try {
         ServerSocket ssock = new ServerSocket(port, max_conn);
         // Start new thread per client connection.
         while (true) {
             Socket sock = ssock.accept();    
             new ClientHandler(sock).start(); 
         }
      }
      catch(IOException e) { System.err.println(e); }
    }
    private static final int port = 9876;
    private static final int max_conn = 100;
}
class ClientHandler extends Thread {
    ClientHandler(Socket sock) { this.sock = sock; }
    public void run() {
       try {
         // Read the request and produce response.
         InputStreamReader isr = new InputStreamReader(sock.getInputStream());
         BufferedReader  in = new BufferedReader(isr);
         String req = in.readLine(); // blocks
         String res = new StringBuffer(req).reverse().toString();
         // Write the response to the client.
         PrintWriter out = new PrintWriter(sock.getOutputStream());
         out.println(res);
         out.flush();
         sock.close();  
       }
       catch(IOException e) { System.err.println(e); }
    } //*** a Thread stops when exiting run()
    private Socket sock;
}