AGSparqlReasoning.java

package com.franz.agbase.examples;

import com.franz.agbase.*;

public class AGSparqlReasoning {

    /**
     * Demonstrates using SPARQL with an RDFS++ entailment regime
     * 
     * @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 a fresh triple-store for this example.
        AllegroGraph ts = ags.renew("sparqlreasoning", AGPaths.TRIPLE_STORES);
        
        // Register your namespaces
        ts.registerNamespace("ex","http://example.org/");
        
        // Add some triples to the store
        ts.addStatement("!ex:a","!ex:owned-by","!ex:b");
        ts.addStatement("!ex:c","!ex:owns","!ex:d");
        ts.addStatement("!ex:jans","!ex:owns","!ex:birra");
        ts.addStatement("!ex:owned-by","!owl:inverseOf","!ex:owns");

        // A SPARQL query to determine what owns what
        String query = 
        "PREFIX ex: <http://example.org/> " +
        "SELECT DISTINCT ?x ?y " +
        "WHERE { ?x ex:owns ?y }";
        
        // First query using SPARQL's standard entailment regime 
        SPARQLQuery sq = new SPARQLQuery();
        sq.setTripleStore(ts);
        sq.setQuery(query);
        sq.setIncludeInferred(false);
        AGSparqlSelect.doSparqlSelect(sq);

        // Now using RDFS++ entailment
        sq.setIncludeInferred(true);
        AGSparqlSelect.doSparqlSelect(sq);

        // Add some more triples to the store
        ts.addStatement("!ex:A","!rdfs:subClassOf", "!ex:B");
        ts.addStatement("!ex:B","!rdfs:subClassOf", "!ex:C");
        ts.addStatement("!ex:a","!rdf:type", "!ex:A");
        
        // A query to determine the types of ex:a 
        query = 
        "PREFIX ex: <http://example.org/> " +
        "PREFIX rdf: <http://www.w3.org/1999/02/22-rdf-syntax-ns#> " +
        "SELECT DISTINCT ?y " +
        "WHERE { ex:a rdf:type ?y }";

        // Query without RDFS++ reasoning
        sq.setQuery(query);
        sq.setIncludeInferred(false);
        AGSparqlSelect.doSparqlSelect(sq);
        
        // Now with reasoning
        sq.setIncludeInferred(true);
        AGSparqlSelect.doSparqlSelect(sq);
        
        // Close the triple store and disconnect from the server.
        ts.closeTripleStore();
        ags.disable();
    }
}

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