The J2EE™ Tutorial Second Edition

Programming Simple Tag Handlers

The classes and interfaces used to implement simple tag handlers are contained in the javax.servlet.jsp.tagext package. Simple tag handlers implement the SimpleTag interface. Interfaces can be used to take an existing Java object and make it a tag handler. For most newly created handlers, you would use the SimpleTagSupport classes as a base class.

The heart of a simple tag handler is a single method—doTag—which gets invoked when the end element of the tag is encountered. Note that the default implementation of the doTag method of SimpleTagSupport does nothing.

A tag handler has access to an API that allows it to communicate with the JSP page. The entry point to the API is the JSP context object (javax.servlet.jsp.JspContext) ...