AGSparqlEngine.java
package com.franz.agbase.examples;
import com.franz.agbase.*;
public class AGSparqlEngine {
/**
* Demonstrates how to set which SPARQL Engine to use for a query.
*
* @param args unused
* @throws AllegroGraphException
*/
public static void main(String[] args) throws AllegroGraphException {
// Connect to server, which must already be running.
AllegroGraphConnection ags = new AllegroGraphConnection();
try {
ags.enable();
} catch (Exception e) {
throw new AllegroGraphException("Server connection problem", e);
}
// Create fresh triple-store for this example.
AllegroGraph ts = ags.renew("sparqlengine", AGPaths.TRIPLE_STORES);
// Load the Kennedy data set
AGLoadNtriples.loadNTriplesWithTiming(ts, AGPaths.dataSources("kennedy.ntriples"));
// Index the store
AGIndexAllTriples.indexAllTriplesWithTiming(ts);
// The query
String query =
"PREFIX ex: <http://example.org/kennedy/> " +
"PREFIX rdf: <http://www.w3.org/1999/02/22-rdf-syntax-ns#> " +
"SELECT ?pfname ?plname ?sfname ?slname " +
"WHERE {" +
"?person ex:first-name 'Arnold' . " +
"?person ex:first-name ?pfname . " +
"?person ex:last-name ?plname . " +
"?person ex:spouse ?spouse . " +
"?spouse ex:first-name ?sfname . " +
"?spouse ex:last-name ?slname . " +
"}";
// Query the store using the (default) AllegroGraph-2 SPARQL Engine
SPARQLQuery sq = new SPARQLQuery();
sq.setTripleStore(ts);
sq.setQuery(query);
sq.setEngine(SPARQLQuery.ENGINE.AG2);
AGSparqlSelect.doSparqlSelect(sq);
// Query the store using the new SPARQL Algebra Engine.
sq.setEngine(SPARQLQuery.ENGINE.ALGEBRA);
AGSparqlSelect.doSparqlSelect(sq);
// Close the triple store and disconnect from the server.
ts.closeTripleStore();
ags.disable();
}
}
| Copyright © 2023 Franz Inc., All Rights Reserved | Privacy Statement | 
|
|
|
|
|
|