Get equivalent classes in order

Question

I need to get equivalent classes of an OWL Class in the same order as in the .owl file.

I use this code

for(OWLClassExpression cls: clazz.getEquivalentClasses(ontology) ) { 

Set <OWLClass> classes_of_the_Expression =cls.getClassesInSignature();
}

But this code gets them randomly.

Please find below an example of cases I treat. Here, dog_owner class is an equivalent Class and intersection of both person and dog classes. By executing my java code I get first dog class, then person class; and I need to get the inverse which means person class then dog class. Because I need precisely the first class of the equivalent classes.

<owl:Class rdf:about="http://owl.man.ac.uk/2005/07/sssw/peopleeemodifiée#dog_owner">
<owl:equivalentClass>
  <owl:Class>
    <owl:intersectionOf rdf:parseType="Collection">
      <owl:Class rdf:about="http://owl.man.ac.uk/2005/07/sssw/peopleeemodifiée#person"/>
      <owl:Restriction>
        <owl:onProperty>
          <owl:ObjectProperty rdf:about="http://owl.man.ac.uk/2005/07/sssw/peopleeemodifiée#has_pet"/>
        </owl:onProperty>
        <owl:someValuesFrom rdf:resource="http://owl.man.ac.uk/2005/07/sssw/peopleeemodifiée#dog"/>
      </owl:Restriction>
    </owl:intersectionOf>
  </owl:Class>
</owl:equivalentClass>
<rdfs:label rdf:datatype="http://www.w3.org/2001/XMLSchema#string"
>dog owner</rdfs:label>
<rdfs:comment rdf:datatype="http://www.w3.org/2001/XMLSchema#string"
></rdfs:comment>

Answer 1

In order to only take into account the named classes inside an intersection included in an equivalent classes axiom, you can use visitors:

OWLEquivalentClassesAxiom ax=null;
ax.accept(new OWLObjectVisitor() {
    @Override
    public void visit(OWLObjectIntersectionOf ce) {
        ce.operands().filter(x->x.isOWLClass()).forEach(x->{
            // this is where x is Person, or any other 
            // named class in the intersection;
            // anonymous classes are skipped
        });
    }
});

For OWLAPI 3:

for(OWLClass clazzzz : ontology.getClassesInSignature()) {
    for(OWLEquivalentClassesAxiom ax: ontology.getEquivalentClassesAxioms(clazzzz)) {
        OWLObjectVisitorAdapter visitor = new OWLObjectVisitorAdapter() {
        @Override
        public void visit(OWLObjectIntersectionOf ce) {
            for (OWLClassExpression e : ce.getOperands()) {
                if (!e.isAnonymous()) {
                    // this is where x is Person, or any other
                    // named class in the intersection;
                    // anonymous classes are skipped
                }
            }
        }
        };
        ax.accept(visitor);
    }
}