I'm not really familiar with the commons.validator package, but usually it simply involves you referencing the correct error in your error variable.
If you are seeing all the errors, you are probably outputting your errors like (this is in
STRUTS taglib):
<html:errors/> would normally print out all errors
while:
<html:errors property="cellphone" />
would print out errors simply for the errors.cellphone
Not sure if that entirely helped, but that's probably very close to how it works in commons.validator.