CODEWITHSUNDEEP
javaowldbpediaowl-api
Nina
Nina

Reputation: 115

can't get the name of Dbpedia classes

While I'm trying to get classes of Dbpedia ontology using the code below 

    public void classofontology(){      

   Set<OWLClass> classes =  ontology.getClassesInSignature();
   System.out.println("le nombre des classes total de l'ontologie est : "+classes.size());          
   for(OWLClass clss: classes) 
    System.out.println(clss.getIRI().getFragment());

           }

I get the total number of classes, So they're all browsed but I can't have the name of classes: I get as output "null" but when I try by using directly clss instead of clss.getIRI().getFragment() I get the IRI . I need just the name of the classes and I can't understand why I can't get it, I would be grateful If you can help me to get it. Thank you

Ps: I notice that classes don't have all the same IRI as you can see for Building and Book classes, Can this be the source of the problem ?

Building IRI gotten by the code http://dbpedia.org/ontology/Building

Book IRI gotten by the code http://schema.org/Book

Upvotes: 0

Views: 59

Answers (1)

Ignazio
Ignazio

Reputation: 10659

In short, IRIs do not have names.

The last part of an IRI (from the last slash or hash character, or digit) is returned by the getFragment() method; however, there is no guarantee that a valid IRI has such a fragment (the IRI might be terminated with a hash or a dash, or it might have only numbers after the last value). The reason behind this is that the fragment must be an XML QName - it is used in RDF/XML for naming tags.

For example, IRI.create("http://www.example.com/test/1234").getFragment() will return an empty string.

As suggested by AKSW, use either a SimpleIRIShortFormProvider or, if your entities have labels, an AnnotationValueShortFormProvider.

Upvotes: 1

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