public void graphQuery()
throws RepositoryException, MalformedQueryException, QueryEvaluationException {
String queryString = "CONSTRUCT {?x a ?y} WHERE { ?x a ?y} ";
// String queryString =
// "SELECT ?x ?y WHERE { ?x a onto:Person. ?x onto:age ?y } ";
GraphQuery graphQuery = (con).prepareGraphQuery(QueryLanguage.SPARQL, queryString);
GraphQueryResult result = graphQuery.evaluate();
while (result.hasNext()) {
Statement st = result.next();
System.out.println(st.toString());
}
result.close();
}
public List<Statement> getAllGraphStatements(String graphName) throws SparqlProxyException {
RepositoryConnection repositoryConnection = super.getConnection(repository);
List<Statement> statements = new ArrayList<Statement>();
String constructGraphQuery =
"CONSTRUCT { ?s ?p ?o } " + "WHERE {" + "GRAPH <" + graphName + "> " + "{ ?s ?p ?o } . }";
try {
GraphQueryResult graphResult =
repositoryConnection
.prepareGraphQuery(QueryLanguage.SPARQL, constructGraphQuery)
.evaluate();
while (graphResult.hasNext()) {
Statement st = graphResult.next();
statements.add(st);
}
} catch (RepositoryException e) {
final String errMsg = "Error while getting all tuples from graph '" + graphName + "'";
LOGGER.error(errMsg, e);
throw new SparqlProxyException(errMsg, e);
} catch (QueryEvaluationException e) {
final String errMsg = "Error while evaluating query: '" + constructGraphQuery + "'";
LOGGER.error(errMsg, e);
throw new SparqlProxyException(errMsg, e);
} catch (MalformedQueryException e) {
final String errMsg = "Malformed query: '" + constructGraphQuery + "'";
LOGGER.error(errMsg, e);
throw new SparqlProxyException(errMsg, e);
} finally {
super.releaseConnection(repositoryConnection);
}
return statements;
}
