Jena Tips
Getting all instances of a class in a model
how to get all instances of a class. How to create instances, Read The Fine Manual.
OntModel model =ModelFactory.createOntModel( ... );
OntClass cls = model.getOntClass(java.lang.String uri);
ExtendedIterator it = cls.listInstances();
while (it.hasNext())
{
System.out.println(it.next());
}