Summary

Tag Libraries (TagLibs) define one or more custom tags that can be used to extend the capabilities of JSP. Judicious use of TagLibs can remove most, if not all, of the Java scriptlets from your Web pages. JSTL provides a number of custom tags that will greatly simplify writing JSPs, but they are not the only custom tags available for you to use; the Apache Jakarta Web site contains a large number of taglibs. In addition, you can write your own custom tags.

Encapsulating the Java code in a custom tag will

• Simplify the writing of Web pages

• Reduce development time by removing awkward Java compiler errors from the JSP-generated code

• Integrate business logic constructs more closely into the JSP syntax

JSTL and custom tags can provide programming constructs, such as iteration and selection (if statements) for your Web pages. Custom tags can also

• Use attributes to pass information from the Web page to the Java code

• Create scripting variables that can be used on the Web page

• Share information between tags in a hierarchical structure

At times, writing your own tags will be the only option, but where possible, using existing libraries reduces the amount of code you have to develop, and that in turn will reduce the overall development time for your application.