Learn Java for Web Development

130 CHAPTER 3: Best Practices in Java EE Web Development

General-Purpose Actions

The general-purpose actions provide the means to work with scoped variables. Table 3-7 describes
the general-purpose actions in the core tag library.

Table 3-6. JSTL Core Library

Functional Areas Description

General-purpose actions Used to manipulate the scoped variables

Conditional actions Used for conditional processing within a JSP page

Iterator actions Used to iterate through collections of objects

URL-related actions Used for dealing with URL resources in a JSP page

Table 3-7. General-Purpose Actions

Action Description

<c:out> Evaluates an expression and outputs the result to the JspWriter object

<c:set> Sets the value of a scoped variable or a property of a target object

<c:remove> Removes a scoped variable

<c:catch> Catches a java.lang.Throwable thrown by any of its nested actions

The Action

The action evaluates an expression and displays the result. It’s equivalent to the JSP syntax
<%= expression %>.

Here’s the syntax without a body:

<c:out value="value" [escapeXml="{true|false}"][default="defaultValue"] />

Here’s the syntax with a body:

<c:out value="value" [escapeXml="{true|false}"]>
default value

Items in brackets are optional

Table 3-8 describes the attributes of . Since this chapter covers JSTL comprehensively,
I recommend you read the JSTL specification^3 for a thorough understanding of how to use JSTL
attributes.

(^3) http://java.coe.psu.ac.th/J2EE/JSTL1.2/jstl-1_2-mrel2-spec.pdf