Programming Jakarta Struts, Second Edition

Installing and Configuring the Validator

The Validator framework is now part of the Jakarta Commons project. It’s included with the Struts main distribution, but you can also get the latest version from the Commons download page at http://jakarta.apache.org/commons/. Unless you need the source code or the absolute latest version, you’ll find all the necessary files included with the Struts 1.1 distribution.

Required Packages

The Validator depends on several other packages to function properly, and the most important of these is the Jakarta ORO package. The ORO package contains functionality for regular expressions, performing substitutions, and text splitting, among other utilities. The libraries were originally developed by ORO, Inc. and donated to the Apache Software Foundation. Earlier versions of the Validator framework depended on a different regular expression package, called Regexp, which is also a Jakarta project. However, ORO was considered the more complete of the two, and the Validator that is included with Struts 1.1 now depends on the ORO package.

Other packages required by the Validator are Commons BeansUtils, Commons Logging, Commons Collections, and Digester. All of the dependent packages for the Validator are included in the Struts 1.1 download. The commons-validator.jar and jakarta-oro.jar files need to be placed into the WEB-INF/lib directory for your web application. The other dependent JAR files must also be present, but they should already be there due to Struts ...