validator-rules.xml and validation.xml this two Struts Validator frameworks file comes with Struts project,(Its is incorported with Struts since version 1.1) to access them I recommend, Just download the struts-blank.war file, unzip it and use it as basis for your struts application, this basic struts project file contains the required .xml file for validation framework.
The details about Struts Validation framework will be found
here ~~