How to retrieve subproperty of a data property in OWL API 4.0

Question

I am using owl api 4.0 and the following code will give me all the property of individuals belonging to class Animal.

OWLClass animalCl = df.getOWLClass(IRI.create(ontologyIRI + "Animal"));
NodeSet<OWLNamedIndividual> animalIndl = reasoner.getInstances(animalCl, false);

for (OWLNamedIndividual animalNamedIndl : animalIndl.getFlattened())
 {
 Set<OWLDataPropertyAssertionAxiom> propAll=    myontology.getDataPropertyAssertionAxioms(animalNamedIndl);  
 for (OWLDataPropertyAssertionAxiom ax: propAll)   
   {
     for (OWLLiteral propertyLit :  EntitySearcher.getDataPropertyValues(animalNamedIndl, ax.getProperty(), myontolgoy))
     System.out.println("The property " + ax.getProperty() + "has value" + propertyLit);  
      }  
}

I have a subproperty "propWt" for every data property. I have used following code:-

NodeSet<OWLDataProperty> properties = reasoner.getSubDataProperties((OWLDataProperty) ax.getProperty(), false);
for (OWLDataProperty mysubproperty : properties.getFlattened())
    {
     System.out.println("the sub property is " + mysubproperty);
    }

instead of

the sub property is <http://localhost:3030/BiOnt.owl#propWt>

i get

 the sub property is owl:bottomDataProperty

What is the problem here?

Answer 1

Since you are using a reasoner for the ontology, I assume you want all subproperties, either asserted or inferred. The reasoner can do the job:

NodeSet<OWLDataProperty> properties = reasoner.getSubDataProperties(property, false);