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AGSparqlReasoning.java

package com.franz.ag.examples;



import com.franz.ag.*;



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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