The Apache Jakarta Project has released Commons Validator 1.1.4, an extensible framework for defining validation methods.
Although it uses XML to define the validation rules,
this component is intended for general data validation, not specifically or even primarily XML validation. 1.1.4 adds getMessage(key) and getMessages() methods to Field and a resource property to the Msg
class to support the resource attribute specified in the DTD.
It is published under the Apache 2.0 license.