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();
    }

}

Up | Next

Copyright © 2014 Franz Inc., All Rights Reserved | Privacy Statement
Delicious Google Buzz Twitter Google+