IterationTag Interface Test JSP

JSP Tutorials - Herong's Tutorial Examples

∟IterationTag Interface Test JSP - TraceTagTest.jspx

This section provides a tutorial example on how to write a JSP page to test the TraceTag class that implements the javax.servlet.jsp.tagext.IterationTag interface.

To test my "hy:trace" tag developed in the previous tutorial, I wrote the following JSP page, TraceTagTest.jspx:

<?xml version="1.0"?>
<jsp:root xmlns:jsp="http://java.sun.com/JSP/Page"
   xmlns:c="http://java.sun.com/jstl/core"
   xmlns:hy="urn:jsptld:/WEB-INF/tlds/HyTaglib.tld" version="2.3">
<!-- TraceTagTest.jspx
 - Copyright (c) 2006 HerongYang.com. All Rights Reserved.
-->
<jsp:directive.page contentType="text/html"/>
<html><body>
<hy:trace myAtt="my value">
<jsp:text>JSP body</jsp:text><br/>
</hy:trace>
</body></html>
</jsp:root>

I put the JSP page on my Tomcat server, and restarted the server. When requesting this JSP page with IE, I got the following output:

setPageContext() called.
setParent() called.
setMyAtt() called.
doStartTag() called.
JSP body
doAfterBody() called.
JSP body
doAfterBody() called.
doEndTag() called.

The output was exactly what I expected. The JSP was indeed evaluated twice as controlled by the returning flag of doAfterBody(). One surprise is that there was no call to release(). I don't know why.