Hi,
This is the code i got through jena community... getting error in
getSubject().....can anyone help me????
import com.hp.hpl.jena.ontology.OntClass;
import com.hp.hpl.jena.ontology.OntModel;
import com.hp.hpl.jena.ontology.OntModelSpec;
import com.hp.hpl.jena.rdf.model.ModelFactory;
import com.hp.hpl.jena.rdf.model.*;
import com.hp.hpl.jena.rdf.model.StmtIterator;
import com.hp.hpl.jena.vocabulary.*;
import com.hp.hpl.jena.query.*;
import com.hp.hpl.jena.vocabulary.RDFS;
import com.hp.hpl.jena.util.iterator.ExtendedIterator;
public class MappingOntologies {
public static void main(String[] args) {
// In most cases, the ontologies already exist, but since
we do not have
// sample data here, we create minimal ontologies that have
the classes
// that were mentioned, namely Ont1 that has a class
Employee with a
// subclass Age, and Ont2 that has a class Employee.
// Ont1
String NS1 = "http://www.example.com/ont1/";;
OntModel ont1 = ModelFactory.createOntologyModel(
OntModelSpec.OWL_DL_MEM );
OntClass employee1 = ont1.createClass( NS1 + "Employee" );
OntClass age1 = ont1. createClass( NS1 + "Age" );
employee1.addSubClass( age1 );
// Ont2
String NS2 = "http://www.example.com/ont2/";;
OntModel ont2 = ModelFactory.createOntologyModel(
OntModelSpec.OWL_DL_MEM );
OntClass employee2 = ont2.createClass( NS2 + "Employee" );
// Usually when we merge or map ontologies, we are not
modifying either
// ontology, but actually creating some third ontology that
imports the
// others, and adding the mapping axioms to that third
ontology. In OWL
// we would probably do this using owl:imports, but in the
Jena API we
// can just create the third model and add the first two as
submodels.
// Ont3; we make this one an inference model so that we
can get the
// inference that employee2 has age1 is a subclass of
employee2.
OntModel ont3 = ModelFactory.createOntologyModel(
OntModelSpec.OWL_DL_MEM_RULE_INF );
// add the submodels
ont3.addSubModel( ont1 );
ont3.addSubModel( ont2 );
// assert that employee1 is equivalent to employee2
ont3.add( employee1, OWL.equivalentClass, employee2 );
// To see the subclasses of employee2 in the merged/mapped
ontology,
// ask for statements of the form [x, rdfs:subClassOf,
employee2]. Each
// x is a subclass of employee2.
StmtIterator axioms = ont3.listStatements( null,
RDFS.subClassOf, employee2 );
System.out.println( "Subclasses of "+employee2 );
while ( axioms.hasNext() ) {
Resource re=axioms.next().*getSubject()* ;
System.out.println( "\t"+ re);
}
// Alternatively, you could get the employee2 OntClass from
the merged
// model and list its subclasses. It is important to
retrieve the
// OntClass from the merged model, because that is the
model that
// OntClass#listSubClasses will query.
//
// Note: when I run this query, I only one less result
than I do
// in the previous query. I do not see the (trivial)
result that
// employee2 is a subclass of itself. Depending on your
intended
// use, this might be a reason to favor the first approach.
OntClass employee32 = ont3.getOntClass( NS2 + "Employee" );
ExtendedIterator subclasses = employee32.listSubClasses();
System.out.println( "Subclasses of "+employee32 );
while ( subclasses.hasNext() ) {
System.out.println( "\t"+subclasses.next() );
}
}
}
On Sat, Apr 27, 2013 at 8:04 PM, Joshua TAYLOR <[email protected]>wrote:
> On Sat, Apr 27, 2013 at 9:20 AM, suganya <[email protected]> wrote:
> > error in getsubject method;
> >
> > here is a piece of code
> > while ( axioms.hasNext() ) {
> > Resource re=axioms.next().getSubject() ;
> > System.out.println( "\t"+ re);
> > ERROR in netbeans:
> > cannot find symbol
> > symbol: method getSubject()
> > location: class java.lang.Object
>
> That doesn't look like an error in getSubject(). That looks like
> axioms is an iterator over java.lang.Objects, not Jena statements.
> There's not enough code here to tell, though…
>
> //JT
>
> --
> Joshua Taylor, http://www.cs.rpi.edu/~tayloj/
>
--
with regards.....
sugan,...
