[hibernate-dev] [BV] Though about PatternValidator

[Hardy Ferentschik]

If you want to allow the empty string you can start your regular  
expression with the 'empty' or operator '|', eg "|^.*foo.*$".
Now the string can be empty or anything with foo in it.

--Hardy

On Wed, 24 Jun 2009 09:47:56 +0200, Alaa Mohsen <alaa.mohsen at egyptdc.com>  
wrote:

> Hello All,
> I just realized that PatternValidator checks if the String passed to it
> is null or not before checking it's validity, but it doesn't check if the
> String is empty. What if someone wants to put a regular expression
> constraint on a non mandatory field, and the framework he uses sets this
> empty field to an empty string? What do you think?