Java bruteforce lafourcade/MissionCrypto2

static void test(long i2)
    {
        try
        {
            URL url = new URL("http://sancy.univ-bpclermont.fr/~lafourcade/MissionCrypto2/Lettre21");
            String urlStr = "";

            String authStringEnc = new String(Base64.getEncoder().encode(("Ian:" + i2).getBytes()));
            HttpURLConnection HttpurlConnection = (HttpURLConnection)url.openConnection();
            HttpurlConnection.setRequestProperty("Authorization", "Basic " + authStringEnc);

            System.out.println(i2);
            HttpurlConnection.getInputStream();

            System.out.println("Found: " + i2);
            System.exit(0);
        }
        catch(Exception e)
        {
            // test(i - 1);
        }
    }

    static long i = 0L;

    public static void main(String[] args)
    {
        while(true)
        {
            Thread th = new Thread()
            {
                public void run()
                {
                    test(i);
                }
            };
            th.start();
            try
            {
                Thread.sleep(5);
            }
            catch(Exception e)
            {}
            i++;
        }