JSTL based nested iteration - iterator

Question

Assume you have the following code:
<c:if test="${fn:length(myIterator) > 0}">
<span>blabla</span>
<c:forEach var="myVar" items="${myIterator}" varStatus="status">
// some stuff
</c:forEach>
<br />
</c:if>
Note that myIterator is an Iterator (surprise, surprise *g).
The problem is that I do not end up in the each loop and do not see "// some stuff" to happen. I think the reason is that fn:length(myIterator) has already iterated over the Iterator to determine its size so that we have already reached the end when arriving at the forEach loop.
I have not seen any elegant way to reset the iterator manually or so.
Of course I could try using scriptlet code (something like <% myIterator.reset() %>, but I would like to avoid that.
I have also tried something like:
<c:if test="${not empty myIterator}">
But that did not work either (did not even enter the if-clause's body).
Any elegant suggestions?
Thanks.

Answer 1

Why are you referring to an Iterator. That should be a Collection like an ArrayList or something.
an iterator can only be iterated once
[EDIT]
IMHO, the cleanest approach is to change the Java controller to give you a Collection. However, based on your feedback that you dont want to or can't...
Change the Java code
Use Java scriptlets in your JSP
You can solve this with some Javascript/DHTML. Consider this JSP code
<script type="text/javascript">
var loopHasContent = false;
</script>
<div id="loop-content" style="display:none">
<span>blabla</span>
<c:forEach var="myVar" items="${myIterator}" varStatus="status">
<script type="text/javascript">
loopHasContent = true;
</script>
// some stuff
</c:forEach>
<br />
</div>
<script type="text/javascript">
if(loopHasContent) {
document.getElementById("loop-content").style.display = "block";
}
</script>
You only reference the Iterable once so your issue goes away. The div is not displayed by default. As long as your forEach loop executes at least once then the javascript variable loopHasContent is set to true, otherwise it remains false. The final javascript trailing the div will only show your loop-content if it has to.