Location of Java Classes
The request time Tag handler classes and the translation time TagExtraInfo classes are just
Java classes. In a Web Application they must reside in the standard locations for Java
classes: either in a JAR file in the WEB INF/lib directory or in a directory in the WEB INF/
The previous rule indicates that a JAR containing a packaged tag libraries can be dropped
into the WEB INF/lib directory to make its classes available at request time (and also at
translation time, see Section 5.3.2). The mapping between the URI and the TLD is explained
Tag Library directive
directive in a JSP page declares that the page uses a tag library, uniquely
identifies the tag library using a URI and associates a tag prefix that will distinguish usage of
the actions in the library.
If a JSP container implementation cannot locate (following the rules described in
Section 5.3.1) a tag library description for a given URI, a fatal translation error shall result.
It is a fatal translation error for the
directive to appear after actions using the prefix
introduced by the
Tag Library Descriptor
The Tag Library Descriptor (TLD) is an XML document that describes a tag library. The
TLD for a tag library is used by a JSP container to interpret pages that include
directives referring to that tag library. The TLD is also used by JSP page authoring tools that
will generate JSP pages that use a library, and by authors who do the same manually.
The TLD includes documentation on the library as a whole and on its individual tags, version
information on the JSP container and on the tag library, and information on each of the
actions defined in the tag library.
Each action in the library is described by giving its name, the class for its tag handler,
optional information on a
class, and information on all the attributes of the
action. Each valid attribute is mentioned explicitly, with indication on whether it is
mandatory or not, whether it can accept request time expressions, and additional information.