Integer i = 0;
    private static String getPath(String prefix, Integer id)    {        String suffix = "";        Integer remaining = id;        Integer dirno = 0;        Integer i = 0;                if (id == null)            throw new NullPointerException("Expecting a not-null id.");        while (remaining > 999)        {            if (i > 0)            {                dirno = remaining % 1000;                suffix = dirno + "/" + suffix;            }            remaining /= 1000;            i++;        }                return root + prefix + suffix + id;    }