[Pellet-users] NPE When trying to create Pellet OntModel

[Daniel E. Renfer]

Hello,

I am trying to create an ontology model to do some reasoning with Pellet 
against a model stored in MySQL for a servlet. Creating and using the 
db-backed model and running SPARQL queries against it is working fine, 
but when I try to create an OntModel, I am getting an error.

My code looks more or less like this:

OntModelSpec spec = new OntModelSpec(PelletReasonerFactory.THE_SPEC );
spec.setImportModelMaker( maker );
Reasoner reasoner = PelletReasonerFactory.theInstance().create();
spec.setReasoner(reasoner);
OntModel ontModel = ModelFactory.createOntologyModel(spec, dbModel); /* 
line 101 */

and the error I'm getting is this:

java.lang.NullPointerException
	at java.util.Hashtable.put(Unknown Source)
	at 
org.mindswap.pellet.datatypes.DatatypeReasoner.defineDatatype(DatatypeReasoner.java:187)
	at 
org.mindswap.pellet.datatypes.DatatypeReasoner.<init>(DatatypeReasoner.java:101)
	at org.mindswap.pellet.ABox.<init>(ABox.java:194)
	at org.mindswap.pellet.KnowledgeBase.clear(KnowledgeBase.java:357)
	at org.mindswap.pellet.KnowledgeBase.<init>(KnowledgeBase.java:267)
	at org.mindswap.pellet.jena.OWLReasoner.<init>(OWLReasoner.java:90)
	at org.mindswap.pellet.jena.PelletInfGraph.<init>(PelletInfGraph.java:163)
	at org.mindswap.pellet.jena.PelletReasoner.bind(PelletReasoner.java:84)
	at 
com.hp.hpl.jena.ontology.impl.OntModelImpl.generateGraph(OntModelImpl.java:2729)
	at com.hp.hpl.jena.ontology.impl.OntModelImpl.<init>(OntModelImpl.java:143)
	at com.hp.hpl.jena.ontology.impl.OntModelImpl.<init>(OntModelImpl.java:124)
	at 
com.hp.hpl.jena.rdf.model.ModelFactory.createOntologyModel(ModelFactory.java:402)
	at 
net.kronkltd.mycyclopedia.processor.rdf.JenaProcessor.getModel(JenaProcessor.java:101)
	at [snip]

Does anyone have any idea what I am doing wrong? Could this be related 
to the errors in the org.mindswap.pellet.datatypes.XSD{time related} 
classes?

I am using the xsdlib.jar file that came with Jena 2.5.4 (which appears 
to be identical to the one that Pellet 1.5.1 ships with)

The error I'm getting there is: "The constructor 
BigTimeDurationValueType(BigInteger, BigInteger, BigInteger, BigInteger, 
BigInteger, BigDecimal) is undefined"

Any help would be greatly appreciated.

Daniel E. Renfer
http://kronkltd.net/

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