I am trying to retrieve tree path of the selected node in NodeSelectListener. The code is very simple

 public void processSelection(NodeSelectedEvent event) {
 log.info("In nodeSelected() ...");
 UIComponent comp = (UIComponent) event.getComponent();
 log.info("component is " + comp.getClass().getName());
 HtmlTree tree = (HtmlTree) comp;
 ....
 ....
 }

but always receive an InvocationTargetException at line

HtmlTree tree = (HtmlTree) comp;

Appserver output, stack trace of the exception is not available.

09:44:32,693 INFO [OppSearchAction] In select()......
09:44:35,630 INFO [OppTreeBean] In nodeSelected() ...
09:44:35,630 WARN [lifecycle] /oppStructure.xhtml @22,123 nodeSelectListener="#
{oppTreeBean.processSelection}": java.lang.reflect.InvocationTargetException
09:44:35,740 INFO [OppTreeBean] In select() ...

I did more tests and figured out the exception occurs whenever class "HtmlTree" is refered, such as

log.info("component class " + HtmlTree.class);

Could anybody explain what's wrong, I am really frustrated.

Thanks,

ylx