How to check in JSTL whether object is String or Collection?

问题

I'm using JSTL and want to check whether an object is a String or a Collection.

fn:length returns results on both types (stringsize or number of elements in the collection).

<c:if test="${fn:length(item)>1}">
   <c:out value="${fn:length(item)} " />
</c:if>

How can I determine which one I've got?

回答1:

You could look at the class name. For example:

<c:if test="${item.class.simpleName == 'String'}">
   <!-- it's a String! -->
</c:if>

回答2:

item.class lead to errors when using with tomcat 7. For me this works (although it's dirtier):

${item.link.getClass().simpleName == 'String'}

来源：https://stackoverflow.com/questions/7013973/how-to-check-in-jstl-whether-object-is-string-or-collection