Demo4.java
/*******************************************************************************
* Copyright (c) 2019 Eclipse RDF4J contributors.
*
* All rights reserved. This program and the accompanying materials
* are made available under the terms of the Eclipse Distribution License v1.0
* which accompanies this distribution, and is available at
* http://www.eclipse.org/org/documents/edl-v10.php.
*
* SPDX-License-Identifier: BSD-3-Clause
*******************************************************************************/
package demos;
import java.util.Arrays;
import org.eclipse.rdf4j.federated.FedXFactory;
import org.eclipse.rdf4j.federated.repository.FedXRepository;
import org.eclipse.rdf4j.query.TupleQuery;
import org.eclipse.rdf4j.query.TupleQueryResult;
public class Demo4 {
public static void main(String[] args) {
FedXRepository repo = FedXFactory.createSparqlFederation(Arrays.asList(
"http://dbpedia.org/sparql",
"http://data.semanticweb.org/sparql"));
repo.init();
String q = "PREFIX rdf: <http://www.w3.org/1999/02/22-rdf-syntax-ns#>\n"
+ "PREFIX dbpedia-owl: <http://dbpedia.org/ontology/>\n"
+ "SELECT ?President ?Party WHERE {\n"
+ "?President rdf:type dbpedia-owl:President .\n"
+ "?President dbpedia-owl:party ?Party . }";
TupleQuery query = repo.getQueryManager().prepareTupleQuery(q);
try (TupleQueryResult res = query.evaluate()) {
while (res.hasNext()) {
System.out.println(res.next());
}
}
repo.shutDown();
System.out.println("Done.");
System.exit(0);
}
}