Regular Expression

(?=^.{3,63}$)(?!^(\\d+\\.)+\\d+$)(^(([a-z0-9]|[a-z0-9][a-z0-9\\-]*[a-z0-9])\\.)*([a-z0-9]|[a-z0-9][a-z0-9\\-]*[a-z0-9])$)