Re: HTTPException:500 exception while executing a federated SPARQL query with Jena ARQ

[Andy Seaborne]

On 02/12/13 14:33, June wrote:
Dear list,
I am trying to perform a federated SPARQL query by Jena arq for the
first time, and I am using the latest version of Jena.

But I encountered a HTTPException:500 exception for executing the
following query. It will be very helpful if you can give me some tips
about this problem.

What is http://wifo5-04.informatik.uni-mannheim.de/drugbank/sparql 
running? Is it Jena or another system?

If it's Fuseki, what are the messages (and stacktrace) from the server 
log file?

        Andy


PREFIX  drugbank:
<http://wifo5-04.informatik.uni-mannheim.de/drugbank/resource/drugbank/>
PREFIX  sider:
<http://wifo5-04.informatik.uni-mannheim.de/sider/resource/sider/>
PREFIX  owl:  <http://www.w3.org/2002/07/owl#>
PREFIX  rdf:  <http://www.w3.org/1999/02/22-rdf-syntax-ns#>

SELECT  ?drug ?enzyme
WHERE
   { ?drug rdf:type drugbank:drugs .
     ?drug drugbank:enzyme ?enzyme .
     ?enzyme rdf:type drugbank:enzymes
     SERVICE <http://wifo5-04.informatik.uni-mannheim.de/sider/sparql>
       { ?drugInSider owl:sameAs ?drug .
         ?drugInSider rdf:type sider:drugs .
         ?drugInSider sider:sideEffect ?sideEffect .
         ?sideEffect rdf:type sider:side_effects
       }
   }
LIMIT   10

The codes I am using are:

   val query = QueryFactory.create(qStr)
   val qexec =
QueryExecutionFactory.sparqlService("http://wifo5-04.informatik.uni-mannheim.de/drugbank/sparql";,
query)
   try {
     val results = qexec.execSelect()
     while (results.hasNext()) {
       val result = results.next
       println(result.get("drug") + "\t" + result.get("enzyme"))// +
"\t" + result.get("sideEffect"))
     }
   } finally {
     qexec.close();
   }

Many thanks!

Best wishes,

June