Opening a file in my GUI in Windows 7!

Question

Hi fellow programmers,
Does anyone know how can change my code, so i can open a file with the windows 7 handler?
This is my button...
private void jButton7ActionPerformed(java.awt.event.ActionEvent evt) {                                        
        try                                    
               File f = new File("./lib/denticare.pdf");
              if(f.exists()) {
             //this is what i whant to change
              Runtime.getRuntime().exec("rundll32 url.dll,FileProtocolHandler ./lib/denticare.pdf");
              }else {
               Object[] optionss = {"OK"};
             JOptionPane.showOptionDialog(this,
             "O Ficheiro não foi encontrado!\nFicheiro não existe ou foi removido!", "Erro de Abertura do manual",
             JOptionPane.OK_OPTION, JOptionPane.ERROR_MESSAGE, null,
             optionss, optionss[0]);
        } catch (Exception e)
             // System.out.println("Error" + e);
            Object[] optionss = {"OK"};
             JOptionPane.showOptionDialog(this,
             "Erro:" +e.getMessage(), "Erro de Abertura do manual",
             JOptionPane.OK_OPTION, JOptionPane.ERROR_MESSAGE, null,
             optionss, optionss[0]);
    }In windows xp 32 bits i open the file. But cant do it with Windows 7 32bits or 64bits

Answer 1

Thanx
Well i changed it for Desktop.getDesktop.open(f);
private void jButton7ActionPerformed(java.awt.event.ActionEvent evt) {                                        
        try                                    
               File f = new File("./lib/denticare.pdf");
              if(f.exists()) {
             // Runtime.getRuntime().exec("rundll32 url.dll,FileProtocolHandler ./lib/denticare.pdf");
              Desktop.getDesktop().open(f);
              }else {
               Object[] optionss = {"OK"};
             JOptionPane.showOptionDialog(this,
             "O Ficheiro não foi encontrado!\nFicheiro não existe ou foi removido!", "Erro de Abertura do manual",
             JOptionPane.OK_OPTION, JOptionPane.ERROR_MESSAGE, null,
             optionss, optionss[0]);
        } catch (Exception e)
             // System.out.println("Error" + e);
            Object[] optionss = {"OK"};
             JOptionPane.showOptionDialog(this,
             "Erro:\n" +e.getMessage(), "Erro de Abertura do manual",
             JOptionPane.OK_OPTION, JOptionPane.ERROR_MESSAGE, null,
             optionss, optionss[0]);
    }                            But its throwing the execption instead. Maybe my relative path to the file is wrong???