Which line of this code is raising the exception? When I look at the
ResultSetFormatter API online, I see 9 signatures for the out method,
only 2 of which have three parameters, where the third parameter is a
PrefixMapping or Prologue but not a Query. The only one with a Query
parameter is "static void
out(ResultSet qresults, Query query)" (the javadoc doesn't explicitly
say where the output goes). If the exception occurs there, you could
try one of the other PrefixMapping.out methods to see if that avoids the
exception.
On 3/12/2024 1:13 AM, Lorenz Buehmann wrote:
Hi,
how did you setup your project? Which Jena version? Do you use Maven?
Which dependencies? It looks like ARQ.init() hasn't been called which
should happen automatically if the setup of the project is correct.
Cheers,
Lorenz
On 11.03.24 14:44, Anna P wrote:
Dear Jena support team,
Currently I just started to work on a SPARQL project using Jena and I
could
not get a solution when I query a model.
I imported a turtle file and ran a simple query, and the snippet code is
shown below. However, I got the error.
public class App {
public static void main(String[] args) {
try {
Model model = RDFDataMgr.loadModel('data.ttl',
Lang.TURTLE);
RDFDataMgr.write(System.out, model, Lang.TURTLE);
String queryString = "SELECT * { ?s ?p ?o }";
Query query = QueryFactory.create(queryString);
QueryExecution qe = QueryExecutionFactory.create(query,
model);
ResultSet results = qe.execSelect();
ResultSetFormatter.out(System.out, results, query);
qe.close();
} catch (Exception e) {
e.printStackTrace();
}
}
}
Here is the error message:
org.apache.jena.riot.RiotException: Not registered as a SPARQL result
set
output syntax: Lang:SPARQL-Results-JSON
at
org.apache.jena.sparql.resultset.ResultsWriter.write(ResultsWriter.java:179)
at
org.apache.jena.sparql.resultset.ResultsWriter.write(ResultsWriter.java:156)
at
org.apache.jena.sparql.resultset.ResultsWriter.write(ResultsWriter.java:149)
at
org.apache.jena.sparql.resultset.ResultsWriter$Builder.write(ResultsWriter.java:96)
at
org.apache.jena.query.ResultSetFormatter.output(ResultSetFormatter.java:308)
at
org.apache.jena.query.ResultSetFormatter.outputAsJSON(ResultSetFormatter.java:516)
at de.unistuttgart.ki.esparql.App.main(App.java:46)
Thank you for your time and help!
Best regards,
Pan
