Random random = new Random(); StringBuilder builder = new StringBuilder(count); for (int i = 0; i < count; i++) { builder.append(Numbers.charAt(random.nextInt(Numbers.length())));

  Random random = new Random();
        StringBuilder builder = new StringBuilder(count);
        for (int i = 0; i < count; i++) {
            builder.append(Numbers.charAt(random.nextInt(Numbers.length())));