Can we test XPath expression in JSP?

The <x:if> tag evaluates a test XPath expression and if it is true, it processes its body. If the test condition is false, the body is ignored.

Attribute

The <x:if> tag has the following attributes −

Attribute	Description	Required	Default
select	The XPath expression to be evaluated	Yes	None
var	Name of the variable to store the condition's result	No	None
scope	Scope of the variable specified in the var attribute	No	Page

Example

Following is an example that show the use of the <x:if> tag −

<%@ taglib prefix = "c" uri = "https://java.sun.com/jsp/jstl/core" %>
<%@ taglib prefix = "x" uri = "https://java.sun.com/jsp/jstl/xml" %>
<html>
   <head>
      <title>JSTL x:if Tags</title>
   </head>
   <body>
      <h3>Books Info:</h3>
      <c:set var = "xmltext">
         <books>
            <book>
               <name>Padam History</name>
               <author>ZARA</author>
               <price>100</price>
            </book>
            <book>
               <name>Great Mistry</name>
               <author>NUHA</author>
               <price>2000</price>
            </book>
         </books>
      </c:set>
      <x:parse xml = "${xmltext}" var = "output"/>
      <x:if select = "$output//book">
         Document has at least one <book> element.
      </x:if>
      <br />
      <x:if select = "$output/books[1]/book/price > 100">
         Book prices are very high
      </x:if>
   </body>
</html>

Let us now access the above JSP, the following result will be displayed −

Books Info:
Document has at least one <book> element.
Book prices are very high