The Java EE 5 Tutorial

Top-Level Tag Library Descriptor Elements

This section describes some top-level TLD elements. Subsequent sections describe how to declare tags defined in tag files, how to declare tags defined in tag handlers, and how to declare tag attributes and variables.

validator Element

This element defines an optional tag library validator that can be used to validate the conformance of any JSP page importing this tag library to its requirements. Table 8–7 lists the subelements of the validator element.

Table 8–7 validator Subelements

Element 

Description 

validator-class

The class implementing javax.servlet.jsp.tagext.TagLibraryValidator

init-param

(optional) Initialization parameters 

listener Element

A tag library can specify some classes that are event listeners (see Handling Servlet Life-Cycle Events). The listeners are listed in the TLD as listener elements, and the web container will instantiate the listener classes and register them in a way analogous to that of listeners defined at the WAR level. Unlike WAR-level listeners, the order in which the tag library listeners are registered is undefined. The only subelement of the listener element is the listener-class element, which must contain the fully qualified name of the listener class.