jxpath NullPointerException

[Chris Picton <ch...@tangent.co.za>]

Hi all

I am trying to get a Pointer to the last node in a set of nodes, using
the following xpath:

//item[@mutable='1'][last()]

I get the following exception thrown:
---------------
Exception in thread "main" java.lang.NullPointerException
        at
org.apache.commons.jxpath.ri.model.dom.DOMNodeIterator.next(DOMNodeIterator.java:117)
        at
org.apache.commons.jxpath.ri.model.dom.DOMNodeIterator.setPosition(DOMNodeIterator.java:68)
        at
org.apache.commons.jxpath.ri.axes.ChildContext.setPosition(ChildContext.java:106)
        at
org.apache.commons.jxpath.ri.axes.ChildContext.nextNode(ChildContext.java:89)
        at
org.apache.commons.jxpath.ri.axes.PredicateContext.nextNode(PredicateContext.java:53)
        at
org.apache.commons.jxpath.ri.axes.PredicateContext.setPositionStandard(PredicateContext.java:181)
        at
org.apache.commons.jxpath.ri.axes.PredicateContext.setPosition(PredicateContext.java:134)
        at
org.apache.commons.jxpath.ri.compiler.CoreFunction.functionLast(CoreFunction.java:289)
        at
org.apache.commons.jxpath.ri.compiler.CoreFunction.computeValue(CoreFunction.java:213)
        at
org.apache.commons.jxpath.ri.axes.PredicateContext.nextNode(PredicateContext.java:81)
        at
org.apache.commons.jxpath.ri.EvalContext.getSingleNodePointer(EvalContext.java:296)
        at
org.apache.commons.jxpath.ri.compiler.Path.searchForPath(Path.java:183)
        at
org.apache.commons.jxpath.ri.compiler.Path.getSingleNodePointerForSteps(Path.java:159)
        at
org.apache.commons.jxpath.ri.compiler.LocationPath.computeValue(LocationPath.java:82)
        at
org.apache.commons.jxpath.ri.JXPathContextReferenceImpl.getPointer(JXPathContextReferenceImpl.java:400)
        at
org.apache.commons.jxpath.ri.JXPathContextReferenceImpl.getPointer(JXPathContextReferenceImpl.java:396)
        at test.main(test.java:19)
--------------------




I have attached my test.java and instance.xml for perusal.

If anyone can tell me why my code is failing, I would appreciate it.

Regards

Chris