[Geotools-gt2-users] NullPointerException in Collection_SumFunction.calculateSum

[<ksa...@we...>]

Hello,

I wanted to use Collection_SumFunction.calculateSum(featureCollection,
attribute) to get the sum of the attribute in the FeatureCollection, but =
I
got a NullPointerException in =
SubFeatureCollection.accepts(FeatureVisitor,
ProgressListener) when executing progress.complete(). My workaround is =
to
pass a NullProgressListener as can be seen in the following code =
snippet:
>>>
SumVisitor sv =3D new SumVisitor(attributeName,
featureCollection.getSchema());
featureCollection.accepts(sv, new NullProgressListener());
<<<
In SubFeatureCollection.accepts(FeatureVisitor, ProgressListener) the =
check,
if null is passed as listener is commented out. I assume, this is my
problem. So my questions are: Is it done by purpose? Or do I try to use =
the
Collection_SumFunction in a wrong way? Anyway, I can work with the
workaround, I just wanted to be sure to understand the
Collection_SumFunction class right.

Regards,
Kerstin S=E4lzer