i use Struts and JSTL tags. When Struts Action throws exception, the error jsp 
page would be opened as to catch and display the exception. You know, Struts 
set exception infos to request attribute Global.EXCEPTION_KEY
("org.apache.struts.action.EXCEPTION"). So, if use struts logic & bean tag, it 
looks like this:
<logic:present name="org.apache.struts.action.EXCEPTION">
	<h4>Stack</h4>
	<pre>
    <%
    		Exception e = (Exception) request
    		.getAttribute("org.apache.struts.action.EXCEPTION");
    		e.printStackTrace(new PrintWriter(out));
    %>
  </pre>
</logic:present>
If changed to jstl, it would like this:
<c:if test="${org.apache.struts.action.EXCEPTION != null}">
	<p />
	<h4>Stack</h4>
	<pre>
    <%
    		Exception e = (Exception) request
    		.getAttribute("org.apache.struts.action.EXCEPTION");
    		e.printStackTrace(new PrintWriter(out));
    %>
  </pre>
</c:if>
But the EL parse class explains the expression as org object,and apache 
attribute...
So, how to do if using the JSTL?