GettingStartedDemoMinimal.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.List;

import org.eclipse.rdf4j.federated.FedXFactory;
import org.eclipse.rdf4j.federated.repository.FedXRepository;
import org.eclipse.rdf4j.query.BindingSet;
import org.eclipse.rdf4j.query.QueryResults;
import org.eclipse.rdf4j.repository.util.Repositories;

public class GettingStartedDemoMinimal {

	public static void main(String[] args) {

		FedXRepository repository = FedXFactory.newFederation()
				.withSparqlEndpoint("http://dbpedia.org/sparql")
				.withSparqlEndpoint("https://query.wikidata.org/sparql")
				.create();

		String query = "PREFIX wd: <http://www.wikidata.org/entity/> "
				+ "PREFIX wdt: <http://www.wikidata.org/prop/direct/> "
				+ "SELECT * WHERE { "
				+ " ?country a <http://dbpedia.org/class/yago/WikicatMemberStatesOfTheEuropeanUnion> ."
				+ " ?country <http://www.w3.org/2002/07/owl#sameAs> ?countrySameAs . "
				+ " ?countrySameAs wdt:P2131 ?gdp ."
				+ "}";

		List<BindingSet> res = Repositories.tupleQuery(repository, query, it -> QueryResults.asList(it));
		res.forEach(bs -> System.out.println(bs));

		repository.shutDown();
	}
}