Hour 17. The JSP Standard Tag Library

What You'll Learn in This Hour:

• How to install and use JSTL

• How to use the Core Tag Library

• How to use the Function Library

One of the goals of tag libraries is to make it easier to create and edit JSPs with automated tools. The presence of Java code within a JSP makes it difficult to parse a JSP, because Java's syntax is considerably more complex than HTML or XML. Because JSP tags use XML's syntax rules, automated XML and HTML editors can process the tags easily.

When you use custom tags, you often find that you still need to insert Java code to display values or execute loops. The Java Standard Tag Library (JSTL) reduces the need for embedded Java code by providing tags that perform many common functions. By using JSTL in conjunction with custom tags, it is possible to write fairly complex JSPs without writing any Java.

JSTL interoperates with JavaBeans defined by the <jsp:useBean> tag, as well as any variables defined by custom tags.