Generic Java library for validating data constraints.

A common issue when receiving data either electronically or from
user input is verifying the integrity of the data. This work is
repetitive and becomes even more complicated when different sets
of validation rules need to be applied to the same set of data
based on locale for example. Error messages may also vary by
locale. This package attempts to address some of these issues and
speed development and maintenance of validation rules.

WWW: http://jakarta.apache.org/commons/validator/