Chapter 11. The Validator Framework

The Struts framework allows input validation to occur inside the ActionForm. To perform validation on data passed to a Struts application, developers must code special validation logic inside each ActionForm class. Although this approach works, it has some serious limitations. This chapter introduces David Winterfeldt's Validator framework, which was created specifically to work with the Struts components and to help overcome some of these limitations.

The Validator allows you to declaratively configure validation routines for a Struts application without programming special validation logic. The Validator has become so popular and widely used by Struts developers that it has been added to the list of Jakarta projects and to the main Struts distribution.