问题
Let's consider a
(1) P Domain CSuper
(2) CSub subClassOf CSuper
Using Jena, I'm trying to list the declared properties for CSub. What I believe is that P mustn't be listed as a declared property for CSub. My justification: P is a declared property for CSub, iff CSub is a domain for P, from (1) CSuper is a domain for P which doesn't imply that CSub is also a domain; (1) means that if (x, y) is P, then x is CSuper, clearly x may (not) be CSub.
The surprising thing is that Jena is listing P as a declared property for CSub when using listDeclaredProperties method even using OntModelSpec.OWL_DL_MEM_RULE_INF or Pellet! Am I missing something?
Update: What does a declared property for some class mean? Does it mean the classes that the property is a domain of them!
回答1:
You want:
theClass.listDeclaredProperties(false);
From the documentation:
listDeclaredProperties()Equivalent to calling listDeclaredProperties(boolean) with default value direct = false.
direct- If true, restrict the properties returned to those directly associated with this class. If false, the properties of super-classes of this class will not be listed among the declared properties of this class.
I think you've misunderstood declared properties. This returns properties that a class may (or must) have. Suppose we have a class hierarchy:
A > B > C
and also:
P domain B
All Bs and Cs may have property P -- no contradiction there. However it's not true that all As may have property P -- the not-Bs are the problem.
来源：https://stackoverflow.com/questions/28841701/jena-listdeclaredproperties-semantics