OWL-S Precondition Check

Hello,

 

i am new to OWL-S. I would like to implement in Eclipse an Precondition
Check for OWL-S Services.

 

Can someone tell me, how I can do this? Or are there any examples/tutorials?

 

I have tried the PreconditionCheck Example which is included in the OWL-S
API, but it didn't work. I throws always following exception:

 

Precondition check disabled

 

---------------------------

 

Trying unsupported language pair...

 

Exception in thread "main" java.lang.NullPointerException

 

      at impl.jena.OWLModelImpl.isTrue(OWLModelImpl.java:946)

 

 
atimpl.owls.generic.expression.SWRLExpressionImpl.isTrue(SWRLExpressionImpl.
java:66)

 

      at reasoning.PreconditionCheck.run(PreconditionCheck.java:54)

 

      at reasoning.PreconditionCheck.main(PreconditionCheck.java:110)