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AGRangeQueries.java

package com.franz.ag.examples;



import com.franz.ag.*;

import org.openrdf.model.Literal;



public class AGRangeQueries {



    /**

     * Demonstrates some basics of range queries. 

     *

     * @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

        AllegroGraph ts = ags.renew("rangequeries", AGPaths.TRIPLE_STORES);



        // Register your namespaces

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

        

        // Add some triples to the store using encoded literals

        // Encoded literals are necessary when performing range queries 

        ts.addStatement("!ex:person1","!ex:age", ts.createEncodedLiteral(28,"int"));

        ts.addStatement("!ex:person2","!ex:age", ts.createEncodedLiteral(30,"int"));

        ts.addStatement("!ex:person3","!ex:age", ts.createEncodedLiteral(32,"int"));

        ts.addStatement("!ex:person4","!ex:age", ts.createEncodedLiteral(40,"int"));

        ts.addStatement("!ex:person5","!ex:age", ts.createEncodedLiteral(42,"int"));

        

        // Retrieve triples by matching a range of objects

        Literal low = ts.createEncodedLiteral(30,"int");

        Literal high = ts.createEncodedLiteral(40,"int");

        System.out.println("Retrieving triples with range 30 <= ex:age <= 40");

        Cursor cc = ts.getStatements(null, "!ex:age", low, high, null, null);

        AGUtils.showTriples(cc);



        // Close the triple store and disconnect from the server

        ts.closeTripleStore();

        ags.disable();

    }



}
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