VirtJenaSPARQLExample9

<docbook><section><title>VirtJenaSPARQLExample9</title><para> </para>
<title> Virtuoso Jena Provider - SPARQL Example 9</title> Virtuoso Jena Provider - SPARQL Example 9
<programlisting>import com.hp.hpl.jena.query.*;
import com.hp.hpl.jena.rdf.model.RDFNode;
import com.hp.hpl.jena.graph.Triple;
import com.hp.hpl.jena.graph.Node;
import com.hp.hpl.jena.graph.Graph;
import com.hp.hpl.jena.rdf.model.*;
import java.util.Iterator;

import virtuoso.jena.driver.*;

public class VirtuosoSPARQLExample9 {

	/**
	 * Executes a SPARQL query against a virtuoso url and prints results.
	 */
	public static void main(String[] args) {

		String url;
		if(args.length == 0)
		    url = &quot;jdbc:virtuoso://localhost:1111&quot;;
		else
		    url = args[0];

/*			STEP 1			*/
		VirtGraph set = new VirtGraph (url, &quot;dba&quot;, &quot;dba&quot;);

/*			STEP 2			*/
                String str = &quot;CLEAR GRAPH &lt;http://test1&gt;&quot;;
                VirtuosoUpdateRequest vur = VirtuosoUpdateFactory.create(str, set);
                vur.exec();                  

                str = &quot;INSERT INTO GRAPH &lt;http://test1&gt; { &lt;http://aa&gt; &lt;http://bb&gt; &#39;cc&#39; . &lt;http://aa1&gt; &lt;http://bb&gt; 123. }&quot;;
                vur = VirtuosoUpdateFactory.create(str, set);
                vur.exec();                  


/*		Select all data in virtuoso	*/
		Query sparql = QueryFactory.create(&quot;SELECT * FROM &lt;http://test1&gt; WHERE { ?s ?p ?o }&quot;);
		VirtuosoQueryExecution vqe = VirtuosoQueryExecutionFactory.create (sparql, set);
		ResultSet results = vqe.execSelect();
                System.out.println(&quot;\nSELECT results:&quot;);
		while (results.hasNext()) {
			QuerySolution rs = results.nextSolution();
		    RDFNode s = rs.get(&quot;s&quot;);
		    RDFNode p = rs.get(&quot;p&quot;);
		    RDFNode o = rs.get(&quot;o&quot;);
		    System.out.println(&quot; { &quot; + s + &quot; &quot; + p + &quot; &quot; + o + &quot; . }&quot;);
		}

		sparql = QueryFactory.create(&quot;DESCRIBE &lt;http://aa&gt; FROM &lt;http://test1&gt;&quot;);
		vqe = VirtuosoQueryExecutionFactory.create (sparql, set);

		Model model = vqe.execDescribe();
 	        Graph g = model.getGraph();
                System.out.println(&quot;\nDESCRIBE results:&quot;);
	        for (Iterator i = g.find(Node.ANY, Node.ANY, Node.ANY); i.hasNext();) 
	           {
	              Triple t = (Triple)i.next();
		      System.out.println(&quot; { &quot; + t.getSubject() + &quot; &quot; + 
		      				 t.getPredicate() + &quot; &quot; + 
		      				 t.getObject() + &quot; . }&quot;);
	        }


		sparql = QueryFactory.create(&quot;CONSTRUCT { ?x &lt;http://test&gt; ?y } FROM &lt;http://test1&gt; WHERE { ?x &lt;http://bb&gt; ?y }&quot;);
		vqe = VirtuosoQueryExecutionFactory.create (sparql, set);

		model = vqe.execConstruct();
 	        g = model.getGraph();
                System.out.println(&quot;\nCONSTRUCT results:&quot;);
	        for (Iterator i = g.find(Node.ANY, Node.ANY, Node.ANY); i.hasNext();) 
	           {
	              Triple t = (Triple)i.next();
		      System.out.println(&quot; { &quot; + t.getSubject() + &quot; &quot; + 
		      				 t.getPredicate() + &quot; &quot; + 
		      				 t.getObject() + &quot; . }&quot;);
	        }


		sparql = QueryFactory.create(&quot;ASK FROM &lt;http://test1&gt; WHERE { &lt;http://aa&gt; &lt;http://bb&gt; ?y }&quot;);
		vqe = VirtuosoQueryExecutionFactory.create (sparql, set);

		boolean res = vqe.execAsk();
                System.out.println(&quot;\nASK results: &quot;+res);


	}
}
</programlisting><para> </para>
</section></docbook>