What s Next

JSTL and JSP-EL Support

JSTL is a specification for a library of tags that provide a collection of common functionality to Web designers using JSP The JSTL specification can be found at http://java.sun.com/products/jsp/jstl/. The library was developed Some of the functionality provided in the tag library is:

• Core functions (e.g., session tracking, runtime conditions, looping, and importing content)

• XML processing

• Internationalization

• Database Access

The URIs for each type of functionality in the library are shown in Table 3.5.

Table 3.5: URls for JSTL Functionality

FUNTIONAL AREA	URI	PREFIX
Core	http://java.sun.com/jstl/core	c
XML processing	http://java.sun.com/jstl/xml	x
118N capable formatting	http://java.sun.com/jstl/fmt	fmt
Database access (SQL)	http://java.sun.com/jstl/sql	sql

The Resin 3.x server line supports the JSTL specification. With JSTL, we can do things like:

 <c:if test="${!empty cookie.userName}">     Welcome back <c:out value="${cookie.userName.value}" /> </c:if> 

Another important advance in the Resin 3.x server line is support for JSP-EL. JSP-EL is a simple language for accessing data in a JSP page. With JSP-EL, information can be stored in places like a pageContext or a request. For example:

 <% boolean newUser = true; pageContext.setAttribute("userStatus", new Boolean(newUser)); %> 

The stored variable can then be used later in the page:

 <c:if test="${userStatus}"> User is new </c:if> 

In the spirit of JSTL, Resin includes support for tag files as defined in JSP 2.0. For example, we might have a tag file defined as:

 <%@ attribute name="a" type="java.lang.String" required="true" %> A sample tag: ${a} 

The tag file should be used in a JSP file:

 <%@ taglib prefix="x" tagdir="WEB-INF/tags" %> <X:test a="Test 1"/>