Parantheses problem with UrlValidator

One of our users got an error message when trying to add a new URL:

'http://en.wikipedia.org/wiki/Genus_(mathematics)' is not a valid URL

I just created very quickly a junit test and it fails:

String[] schemes =

;
UrlValidator urlValidator = new UrlValidator(schemes);
assertTrue(urlValidator.isValid("http://en.wikipedia.org/wiki/Genus_(mathematics)"));