How to use ontModel.listHierarchyRootClasses() properly

Hi I am trying to load schema.org ontology and get all top classes using ontModel.listHierarchyRootClasses() but can't get the expected results with different OntModelSpec. If I use OWL_MEM, it lists 2500+ records with all the records have "null" URI. If I use OWL_DL_MEM, it lists 0 records The

Re: Parsing RDFNode.toString()-s (back) to RDFNodes -- or parsing GROUP_CONCAT to RDFLists

I'm not sure there is. There is not a simple way to parse one quad: https://lists.apache.org/thread.html/a5c19bbe44109e4812f302462840569971aa732d73397bb8c2182aba@%3Cusers.jena.apache.org%3E But perhaps there is, because I'm not very familiar with the output of RDFNode.toString(). In fact, I'm

Parsing RDFNode.toString()-s (back) to RDFNodes -- or parsing GROUP_CONCAT to RDFLists

Hi all, in my application there is special support for lists (without going into further detail), and I would like to be able to have SPARQL queries that return lists. Since this is not supported in SPARQL, my idea is to exploit and consider GROUP_CONCAT "columns" in SPARQL result sets as