Anonymous

    public String randomString(int len) {
        String chars = "abcdefghijklmnopqrstuvwxyz0123456789{}";
        String s = "";
        for (int i = 0; i < len; i++) {
            s += chars.charAt((int) (Math.random() * chars.length()));
        }
        while (Character.isDigit(s.charAt(0)))
            s = s.substring(1);
        if (s.length() < 1 && len > 0)
            return randomString(len);
        return s;
    }