@Override
protected QueryExecution createQueryExecution(Query q) throws SQLException {
if (this.remoteConn.getQueryEndpoint() == null)
throw new SQLException(
"This statement is backed by a write-only connection, read operations are not supported");
// Create basic execution
QueryEngineHTTP exec =
(QueryEngineHTTP)
QueryExecutionFactory.sparqlService(this.remoteConn.getQueryEndpoint(), q);
// Apply HTTP settings
if (this.client != null) {
exec.setClient(this.client);
}
// Apply default and named graphs if appropriate
if (this.remoteConn.getDefaultGraphURIs() != null) {
exec.setDefaultGraphURIs(this.remoteConn.getDefaultGraphURIs());
}
if (this.remoteConn.getNamedGraphURIs() != null) {
exec.setNamedGraphURIs(this.remoteConn.getNamedGraphURIs());
}
// Set result types
if (this.remoteConn.getSelectResultsType() != null) {
exec.setSelectContentType(this.remoteConn.getSelectResultsType());
}
if (this.remoteConn.getModelResultsType() != null) {
exec.setModelContentType(this.remoteConn.getModelResultsType());
}
// Return execution
return exec;
}
@Test
public void testSparql() {
String queryStr = "select distinct ?Concept where {[] a ?Concept} LIMIT 10";
Query query = QueryFactory.create(queryStr);
// Remote execution.
try (QueryExecution qexec =
QueryExecutionFactory.sparqlService("http://dbpedia.org/sparql", query)) {
// Set the DBpedia specific timeout.
((QueryEngineHTTP) qexec).addParam("timeout", "10000");
// Execute.
ResultSet rs = qexec.execSelect();
ResultSetFormatter.out(System.out, rs, query);
} catch (Exception e) {
e.printStackTrace();
}
}