Overriding J2EE classes

[Shivani Chandna]

(Question 1).
In the chapter related to web application deployment there is a point made in the question in the end - which states that :

J2EE classes should not be overriden.

Is not overriding classes same as extending classes?. What is the difference. (Is it something as registering your own defined classes for the a given behaviour - like in struts - but I dont see any kind of registration of class names in any config file?)

For JSTL - we have classes defined for <c:forEach> action - . It is written in the specs that we can define our own classes and use them for such actions. Given that JSTL is part of J2EE framework - would not the above statement be wrong in that case?

Question 2
I had read that we can define our tags within <c:forEach> or <c:forToken>
Eg:

 <c:forEach items="${collectn}" var="currentVar">
   <my:simpleTag/>
 </c:forEach>

What I wish to know is : can the class which is responsible for simpleTag be able to access the currentVar ? - How does it access it?.


Thanks,
Shivani.

[Shivani Chandna]

Well.... Any answers to the above query?

Regards,
Shivani.

[Flom Xanther]

well I don't know in detail,
but your second question sounds like you want to use getParent() on the simpletag.

Look at the api for more info.

Mfg,
Flom

[Christophe Verré]

Question 2:
Yes, with getParent, you can try something like this :

In JSP:
<c:forEach var="currentVal" begin="1" end="3">
<mytags:mysimpletag/>
</c:forEach>
 
In SimpleTag:
 
public void doTag() throws JspException, java.io.IOException {
JspTag parent = getParent();
if ( parent != null ) {
getJspContext().getOut().println("Found Parent<br>");

if ( parent instanceof LoopTagSupport )
{
LoopTagSupport loopTag = (LoopTagSupport)parent;
getJspContext().getOut().println("Current value: " + loopTag.getCurrent() + "<br>");}

} else {
getJspContext().getOut().println("Parent not found<br>");
}

}

[ August 08, 2006: Message edited by: Satou kurinosuke ]

[Rahul Mahindrakar]

Hi

Unless you post the link to the reference we will not be able to get the context within which the statement was made

Rahul