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AGFederationSparqlReasoning.java

package com.franz.agbase.examples;



import com.franz.agbase.*;



public class AGFederationSparqlReasoning {



    /**

     * Demonstrates SPARQL over a federation with and without reasoning.

     * 

     * @param args unused

     * @throws AllegroGraphException

     */

    public static void main(String[] args) throws AllegroGraphException {

        

        // Connect to the default server, which must already be running.

        AllegroGraphConnection ags = new AllegroGraphConnection();

        try {

            ags.enable();

        } catch (Exception e) {

            throw new AllegroGraphException("Server connection problem.", e);

        }



        // Register namespaces

        // Future AllegroGraph instances on this connection will get this.

        ags.registerNamespace("ex", "http://example.org/");

        

        // Create triple stores for this example

        AllegroGraph ts1 = ags.renew("ontology", AGPaths.TRIPLE_STORES);

        AllegroGraph ts2 = ags.renew("facts", AGPaths.TRIPLE_STORES);

        

        // Create a federated store consisting of the first 2 open stores above 

        AllegroGraph[] parts = {ts1,ts2};

        AllegroGraph fed = ags.federate("federation", parts, true);



        // Add some ontology

        ts1.addStatement("!ex:SmallBlackDog","!rdfs:subClassOf","!ex:BlackDog");  

        ts1.addStatement("!ex:BlackDog","!rdfs:subClassOf","!ex:Dog");  

        ts1.addStatement("!ex:Dog","!rdfs:subClassOf","!ex:Mammal");  

        ts1.addStatement("!ex:Giraffe","!rdfs:subClassOf","!ex:Mammal");  

        ts1.addStatement("!ex:Lion","!rdfs:subClassOf","!ex:Mammal");  

        ts1.addStatement("!ex:Mammal","!rdfs:subClassOf","!ex:Animal");  

         

        // Add some facts 

        ts2.addStatement("!ex:Abbey","!rdf:type","!ex:BlackDog");

        

        String query = 

            "PREFIX ex: <http://example.org/>"

            + "PREFIX rdf: <http://www.w3.org/1999/02/22-rdf-syntax-ns#> "

            + "SELECT ?class "

            + "WHERE { "

            + "  ex:Abbey rdf:type ?class . "

            + "}";

        

        // Sparql query over the federation without reasoning

        SPARQLQuery sq = new SPARQLQuery();

        sq.setTripleStore(fed);

        sq.setQuery(query);

        sq.setIncludeInferred(false);

        AGSparqlSelect.doSparqlSelect(sq);

        

        // Sparql query over the federation with RDFS++ reasoning

        sq.setIncludeInferred(true);

        AGSparqlSelect.doSparqlSelect(sq);

        

        // Close all stores and disconnect from the server

        fed.closeTripleStore();

        ts1.closeTripleStore();

        ts2.closeTripleStore();

        ags.disable();

    }

    

}
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