Chamar relatorio a partir do java

//classe para chamar o relatório
import java.sql.Connection;
 import java.sql.DriverManager;
 import java.sql.PreparedStatement;
 import java.sql.ResultSet;
 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.JasperExportManager;
 import net.sf.jasperreports.engine.JasperFillManager;
 import net.sf.jasperreports.engine.JasperPrint;
 import net.sf.jasperreports.engine.JasperRunManager;
 import net.sf.jasperreports.engine.data.JRBeanArrayDataSource;
 import net.sf.jasperreports.engine.data.JRBeanCollectionDataSource;
 import net.sf.jasperreports.view.JasperViewer;
 
 public class GerarRelatorio {
     Connection conexao = null;
     
     public GerarRelatorio() {
         try {
             Class.forName("sun.jdbc.odbc.JdbcOdbcDriver");
             conexao = DriverManager.getConnection("jdbc:odbc:fonteueg","root","");
             
             //Class.forName("com.mysql.jdbc.Driver");
            // conexao = DriverManager.getConnection("jdbc:mysql://localhost/fonteueg","root","");
               
             //com.mysql.jdbc.Driver
         } catch (Exception e) {
             e. printStackTrace();
         }
     }
         
     public void gerarRelatorioHistoricoEstoque() throws Exception, JRException {
        PreparedStatement stmt = null;
        ResultSet rs = null;
        //String caminhoRelatorioJasper = "F:\\AutoSystem\\src\\modelo\\conexao\\historico_estoque.jasper";
        String caminhoRelatorioJasper = "C:\\projetoUeg\\projeto\\relMateriais.jasper";
        
        try{
            stmt = conexao.prepareStatement( "select * from TMateriais");                      
            
            rs = stmt.executeQuery();
            
            JRResultSetDataSource ds = new JRResultSetDataSource(rs);
             
            Map parametros = new HashMap();
            
            try{
                JasperPrint impressao = JasperFillManager.fillReport( caminhoRelatorioJasper,parametros,ds);
                
                JasperViewer viewer = new JasperViewer(impressao, true);
                
            }
            
            catch (JRException e){
                System.out.println("erro: " + e.getMessage());
                e.printStackTrace();
            
            }
            
        }
        catch(Exception e) {
            e.printStackTrace();       
        }
        
        
        
        
         
     }
     
     public static void main(String[] args) throws JRException, Exception
{
new GerarRelatorio().gerarRelatorioHistoricoEstoque();
}

 
 }