How to make checkstyle ignore "Import from illegal package"

[Xu, Yaning]

Hi all,

                When I run "mvn checkstyle:check", there is an error in 
Rc4Maker -" (imports) IllegalImport: Import from illegal package - 
sun.security.provider.MD4". However, we indeed need to import it.

                So how can I make checkstyle igore it?


Regards,

Yaning