Dasdos de relatorio não aparecem quando exibidos

import java.io.InputStream;
import java.sql.Connection;
import java.sql.ResultSet;
import java.sql.SQLException;
import java.sql.Statement;
import java.util.HashMap;
import java.util.Map;
import net.sf.jasperreports.engine.JRException;
import net.sf.jasperreports.engine.JRResultSetDataSource;
import net.sf.jasperreports.engine.JasperCompileManager;
import net.sf.jasperreports.engine.JasperFillManager;
import net.sf.jasperreports.engine.JasperPrint;
import net.sf.jasperreports.engine.JasperReport;
import net.sf.jasperreports.engine.design.JasperDesign;
import net.sf.jasperreports.engine.xml.JRXmlLoader;
import net.sf.jasperreports.view.JasperViewer;

/**
 *
 * @author Administrador
 */
public class GerarRelatorios extends Exception{

    public Statement stm;
    public ResultSet rs;
    public String layout;
    public GerarRelatorios() throws ExcRepositorio, SQLException, JRException {
    conexao.pegarConexao(); 
    pols();
    ger(layout);
    
    }
    
    public void ger (String layout) throws JRException, SQLException, ExcRepositorio {
        JRXmlLoader.load( layout );
        JasperDesign desenho = new JasperDesign();
        JasperReport relatorio = JasperCompileManager.compileReport( desenho );
        Connection con = conexao.pegarConexao();
        stm = con.createStatement();
        String sql = "SELECT funcionario.codass, nomefun, valor, nomeloja  " +
                      "FROM funcionario " +
                      "LEFT JOIN lojas " +
                      "ON funcionario.codass = lojas.codass";
       rs = stm.executeQuery( sql );
       Map parametros = new HashMap();
       JRResultSetDataSource jrRS = new JRResultSetDataSource( rs );          
       JasperPrint impressao = JasperFillManager.fillReport( relatorio , parametros, con );
       JasperViewer viewer = new JasperViewer( impressao , true );
       viewer.show();
    }   
    public static void main(String[] args) throws Exception {              
        try {
            new GerarRelatorios();
        } catch (Exception ex) {
            ex.printStackTrace();
        }
    }    
public void pols() throws ExcRepositorio, SQLException, JRException{
             JasperPrint rel=null;
         try{
           Connection con = conexao.pegarConexao();
           HashMap parametros = new HashMap();
           String path = "report1.jasper";
           InputStream input = this.getClass().getClassLoader().getResourceAsStream(path);
           rel = JasperFillManager.fillReport(input, parametros, con);
           JasperViewer.viewReport(rel,true);
         }catch (JRException e){
             e.printStackTrace();
         }         
    }
}

JRXmlLoader.load( layout );