Jakarta Struts Cookbook

3.2. Using the Struts-EL Tags

Problem

You want to be able to use JSTL expressions for attribute values on Struts tags.

Solution

Use the tag libraries supplied with the Struts distribution in the contrib/struts-el/lib directory. You will need to copy all the JAR and TLD files from this directory to your application's WEB-INF/lib directory. Use the appropriate taglib directives on JSP pages where you want to use expressions:

<%@ taglib uri="http://jakarta.apache.org/struts/tags-html-el" 
        prefix="html-el" %>

Table 3-2 lists the Struts-EL tag libraries and the corresponding taglib URIs.

Table 3-2. Struts-EL Taglib URIs

Tag library	Struts-EL Taglib URI (1.1)	Struts-EL Taglib URI (1.2)
html-el	http://jakarta.apache.org/struts/tags-html-el	http://struts.apache.org/tags-html-el
bean-el	http://jakarta.apache.org/struts/tags-bean-el	http://struts.apache.org/tags-bean-el
logic-el	http://jakarta.apache.org/struts/tags-logic-el	http://struts.apache.org/tags-logic-el

Discussion

JSTL-style expressions, such as ${foo.bar[4].baz}, are not supported by the base Struts tags. For example, it would be nice if you could format a tag using an expression like the following:

<html:text value="${sessionScope.foo.bar[3]}"/>

Instead, these tags require runtime expressions, which is just Java code:

<html:text 
    value="<%=session.((Foo)getAttribute("foo")).getBar(3)%>"/>

Getting the Java code out of your JSP pages makes your pages less brittle and more maintainable. This lack of EL support was identified ...