some question

[卢思佳]

Now I am learning Jena;

I read a entity in a RDF file and i found the properties .
but when i try to find the datatyperange and the objectrang of the property , 
it fail.
I don't know how to do about it .

my code:

ExtendedIterator rangIterator=property.listRange();
   while (rangIterator.hasNext()){
    OntClass rangClass=(OntClass)rangIterator.next();
    if(rangClass.isUnionClass()){
     System.out.println("data****************");
     UnionClass unionClass=rangClass.asUnionClass();
     rangClassIterator=unionClass.listOperands();
    }
    else{
     rangClassIterator=property.listRange();
    }
   } 
while(rangClassIterator.hasNext()){
    OntClass itemClass=(OntClass)rangClassIterator.next(); 
    if(itemClass.isDatatypeProperty()){
     System.out.println("   datarangClass:"+itemClass.getLocalName()); 
    }
    else{
     System.out.println("   objectrangClass:"+itemClass.getLocalName()); 
    }


it does't work.

thank you !!

lusijia