Unable to populate Data in Jtable from Sparql result

[Mohit G Gupta]

 package tutorial;
        
        import java.io.ByteArrayOutputStream;
        import java.io.File;
        import java.io.FileInputStream;
        import java.io.FileNotFoundException;
        import java.io.IOException;
        import java.io.InputStream;
        
        import com.hp.hpl.jena.datatypes.xsd.XSDDatatype;
        import com.hp.hpl.jena.graph.query.Query;
        import com.hp.hpl.jena.query.QueryExecution;
        import com.hp.hpl.jena.query.QueryExecutionFactory;
        import com.hp.hpl.jena.query.QueryFactory;
        import com.hp.hpl.jena.query.ResultSetFormatter;
        import com.hp.hpl.jena.rdf.model.Model;
        import com.hp.hpl.jena.rdf.model.ModelFactory;
        import com.hp.hpl.jena.rdf.model.Property;
        import com.hp.hpl.jena.rdf.model.Resource;
        import com.hp.hpl.jena.sparql.resultset.ResultSetFormat;
        
        
        
        public class RdfHello {
        
        	private String abc;
        	public String output;
        	com.hp.hpl.jena.query.ResultSet results;
        	/**
        	 * @param args
        	 * @throws IOException 
        	 */
        	public  void getString(String abc){
        		this.abc=abc;
        		
        	}
        	public com.hp.hpl.jena.query.ResultSet getResult()
        	{return results;}
        	
        	public void rdf()throws IOException{
        		Model m=ModelFactory.createDefaultModel();
                String N="http://example.com/test";
                Resource r=m.createResource(N +"r");
                Property p=m.createProperty(N + "s");
                r.addProperty(p, "hello worl", XSDDatatype.XSDstring);
                m.write(System.out,"Turtle");
                
             // Open the  RDF graph from the filesystem
                InputStream in = new FileInputStream(new File("E:\\Applications\\workspace-protoge\\PeriodicTable.owl"));
        
                // Create an empty in-memory model and populate it from the graph
                Model model = ModelFactory.createMemModelMaker().createModel("");
                model.read(in,null); // null base URI, since model URIs are absolute
                in.close();
        
                
        		// Create a new query
               
                String queryString =abc;
                //abc contains the required query passed from a jTextArea
               //PREFIX table: <http://www.daml.org/2003/01/periodictable/PeriodicTable#>
              //SELECT ?name ?symbol ?number
             //FROM <http://www.daml.org/2003/01/periodictable/PeriodicTable.owl>
           //WHERE
           //{
          //?element table:name ?name.
         //?element table:symbol ?symbol.
        //?element table:atomicNumber ?number.
        //}
    	
        
                
                com.hp.hpl.jena.query.Query query = QueryFactory.create(queryString);
        
                // Execute the query and obtain results
                QueryExecution qe = QueryExecutionFactory.create(query, model);
                 results = qe.execSelect();
                
                qe.close();
        
        	}
        	public static void main(String[] args) throws IOException {
        		// TODO Auto-generated method stub
                
                
        	}
        
        }

package tutorial;


import java.awt.EventQueue;

@SuppressWarnings("serial")
public class RESULT extends JFrame {

	private JPanel contentPane;
	private  RdfHello obj;
	private JTable table;

	/**
	 * Launch the application.
	 */
	public static void main(String[] args) {
		EventQueue.invokeLater(new Runnable() {
			public void run() {
				try {
					//RESULT frame = new RESULT(obj);
					//frame.setVisible(true);
				} catch (Exception e) {
					e.printStackTrace();
				}
			}
		});
	}

	/**
	 * Create the frame.
	 */
	public RESULT(RdfHello obj){
		this.obj=obj;
		setDefaultCloseOperation(JFrame.EXIT_ON_CLOSE);
		setBounds(100, 100, 551, 380);
		contentPane = new JPanel();
		contentPane.setBorder(new EmptyBorder(5, 5, 5, 5));
		setContentPane(contentPane);
		contentPane.setLayout(null);
		
		JTextArea textArea = new JTextArea();
		textArea.setBounds(43, 51, 328, 179);
		contentPane.add(textArea);
		textArea.setText(obj.output);
		ResultTableModel myData = new ResultTableModel(obj.getResult()); 
		table = new JTable(myData);
		table.setBounds(77, 256, 219, 56);
		contentPane.add(table);
		setVisible(true);
		
		
	}
	public RESULT() {
		
	}
}

package tutorial;
import java.util.ArrayList;
import java.util.List;

import javax.swing.table.AbstractTableModel;

import com.hp.hpl.jena.query.QuerySolution;
import com.hp.hpl.jena.query.ResultSet;

public class ResultTableModel extends AbstractTableModel {
	final List<String> variables;
    final List<QuerySolution> results;
    String[] columnNames={"Name",
        "Symbol","Number"
        };

    public ResultTableModel(com.hp.hpl.jena.query.ResultSet resultset) {
       results = new ArrayList<QuerySolution>();
        variables = resultset.getResultVars();
       while (resultset.hasNext()) results.add(resultset.next());
       System.out.println("SIZE"+results.size());//                                      SIZE ==0
    }
    @Override public String getColumnName(int col) {
        return columnNames[col].toString();
    }
    @Override public int getRowCount() { return results.size(); } 
    @Override public int getColumnCount() { return variables.size(); }
    @Override public Object getValueAt(int row, int column) {
         return results.get(row).get(variables.get(column));
    }
}

here ,is the code that creates a object of RdfHello and passes it to Result

ob.rdf();
RdfHello ob=new RdfHello(); new RESULT(ob);

The Result Gui gives an Empty Table while the textarea gives the required output
In ResultTableModel ,i have tried to populate data from resultset but it gives size=0
please help

[Rob Spoor]

You never call method rdf() which actually fills the ResultSet.

[Mohit G Gupta]

You never call method rdf() which actually fills the ResultSet.

i didn't understand .
please be more descriptive.

[Rob Spoor]

You defined method rdf(). This is the only method that reads any data. You do not call this method. Ergo, no data is ever read.

[Mohit G Gupta]

sorry,i missed that line in the code,
rdf method is bring called.
i think there is some problem in the ResultTableModel or Result class

[Rob Spoor]

Then perhaps the problem is you closing the QueryExecution before reading the data from the ResultSet. I don't know how this works in the library you're using, but with JDBC you cannot read anything from a ResultSet after the (Prepared)Statement that created it has been closed. So you may want to check if the ResultSet has any data before you call qe.close(). If this is the case you need to extract the data from the ResultSet before calling this method.

[Mohit G Gupta]

thanks Rob
i commented

qe.close();  

and then ran the code again .still,got the size 0
so,i put the entire code of querying in ResultTableModel ,
then,i got the desired results.

can you tell why it isn't working even after commenting

qe.close();