How can i print a rdfs label with Jena - jena

Question

Hi i have create a new ontology for relate Drugs and diseases; now i query its for recovering the name of Drug related a particular disease.
My code is:
public class Main {
public static void main(String[] args) {
org.apache.log4j.Logger.getRootLogger().setLevel(org.apache.log4j.Level.OFF);
FileManager.get().addLocatorClassLoader(Main.class.getClassLoader());
Model model = FileManager.get().loadModel("Drugs_Diseases.owl");
String strQuery = "PREFIX rdfs: <http://www.w3.org/2000/01/rdf-schema#> "+
"PREFIX des: <http://www.entrez.com/> "+
"SELECT DISTINCT ?subject ?object "
+ "WHERE { "
+ "?subject des:isDrugOfDisease ?object . "
+ "?object rdfs:label ?label . "
+ "FILTER regex(str(?label), \"pain\") }";
Query query = QueryFactory.create(strQuery);
QueryExecution execQuery = QueryExecutionFactory.create(query, model);
try{
ResultSet results = execQuery.execSelect();
while(results.hasNext()){
QuerySolution sol = results.nextSolution();
RDFNode node = sol.get("subject");
String stringPrint = node.asNode().toString();
System.out.println(stringPrint);
}
} finally {
execQuery.close();
}}
}
The results of this query is:
http://www.entrez.com/DAP000017
http://www.entrez.com/DAP000021
but my intent is to have:
Diazepam
Dextropropoxyphene
in OWL i have:
<owl:Class rdf:about="http://www.entrez.com/DAP000021">
<entrez:isDrugOfDisease>
<owl:Class rdf:about="http://orpha.net/ORDO/Orphanet_#DIS_ID_75"/>
</entrez:isDrugOfDisease>
<entrez:id>DAP000021</entrez:id>
<rdfs:label>Diazepam</rdfs:label>
</owl:Class>

Answer 1

SPARQL only returns what you select, thus, you have to select the label in the SPARQL query of course:
SELECT DISTINCT ?drug ?disease ?drugLabel WHERE
?drug des:isDrugOfDisease ?disease .
?drug rdfs:label ?drugLabel .
?disease rdfs:label ?label .
FILTER regex(str(?label), \"pain\")
}
In the code, get the label from the solution object:
while(results.hasNext()){
QuerySolution sol = results.nextSolution();
RDFNode node = sol.get("drug");
String stringPrint = node.asNode().toString();
System.out.println(stringPrint);
// label
String label = sol.getLiteral("drugLabel").getLexicalForm();
System.out.println(label);
}
Note, I changed the variable names. In general, it's easier to read and understand a query if you use meaningful names for the variables.