Hvorfor fungere det ikke?

Det fungere fint med én klient, men ikke multithreaded, hvad skyldes dette? Dette skulle gerne være en multithreading, men det fungere ikke når 2 er online på klienten, det kan serveren ikke tåle.

Kan nogle se fejl?


import java.io.*;
import java.net.*;
import java.io.BufferedReader;
import java.io.IOException;
import java.io.InputStreamReader;
import java.io.PrintWriter;
import java.net.ServerSocket;
import java.net.Socket;

public class CapitalizeServer {


    public static void main(String[] args) throws Exception {
        System.out.println("The capitalization server is running.");
        int clientNumber = 0;
        ServerSocket listener = new ServerSocket(9999);
        try {
            while (true) {
                new Capitalizer(listener.accept(), clientNumber++).start();
            }
        } finally {
            listener.close();
        }
    }


    private static class Capitalizer extends Thread {
        private Socket socket;
        private int clientNumber;

        public Capitalizer(Socket socket, int clientNumber) {
            this.socket = socket;
            this.clientNumber = clientNumber;
            log("New connection with client# " + clientNumber
                  + " at " + socket);
        }



        public void run() {
            try {

 
                BufferedReader in = new BufferedReader(
                        new InputStreamReader(socket.getInputStream()));
                PrintWriter out =
                    new PrintWriter(socket.getOutputStream(), true);

                while (true) {
                    String input = in.readLine();
                    out.println(input + '\0');
                }
            } catch (IOException e) {
                log("Error handling client# " + clientNumber + ": " + e);
            } finally {
                try {
                    socket.close();
                } catch (IOException e) {
                    log("Couldn't close a socket, what's going on?");
                }
                log("Connection with client# " + clientNumber + " closed");
            }
        }


        private void log(String message) {
            System.out.println(message);
        }
    }
}