6. JavaServer Pages Standard Tag Library
The JavaServer Pages Standard Tag Library (JSTL) encapsulates core functionality common to many JSP applications. Instead of mixing tags from numerous vendors in your JSP applications, JSTL allows you to employ a single, standard set of tags. This standardization allows you to deploy your applications on any JSP container supporting JSTL and makes it more likely that the implementation of the tags is optimized.
JSTL has tags such as iterators and conditionals for handling flow control, tags for manipulating XML documents, internationalization tags, tags for accessing databases using SQL, and commonly used functions.
This chapter demonstrates JSTL through excerpts from the JSP version of the Duke's Bookstore application discussed in the earlier chapters. It assumes that you are familiar with the material in the Using Custom Tags (page 141) section of Chapter 4.
This chapter does not cover every JSTL tag, only the most commonly used ones. Please refer to the reference pages at http://java.sun.com/products/jsp/jstl/1.1/docs/tlddocs/index.html for a complete list of the JSTL tags and their attributes.