Use of JSP Tag Libraries

JSP tag libraries are encapsulations of logical constructs, providing for units of reusable functionality. These units of functionality are accessed using custom JSP tags from a JSP page. Consistent with an MVC implementation, JSP tag libraries abstract logic from the JSP presentation layer to the controller layer, thereby reducing Java code within the JSP page. JSP tags are commonly used to implement application-wide functionality that facilitates data presentation such as formatting and processing of output, application wide administrative tasks, defining variables and objects for use within the JSP page, pre- or post-server-side data manipulation, and implementation of server-side processing as required by the application. JSP tag libraries provide for cleaner JSP pages that are more readable, more maintainable, while implementing the MVC architecture. Within this chapter we detail how to use tag libraries in general and specifically how to use the BEA WebLogic provided tag libraries. Tag library creation is addressed within Chapter 18, “Creating JSP Tag Libraries.”