Java - validar JOptionPane.showInputDialog

Object cantidad = JOptionPane.showInputDialog(null, "Pregunta?", "Titulo", JOptionPane.QUESTION_MESSAGE, null, null, 1);

boolean canContinue = false;

        Double number = 0.0;

        do {

            String userResponse = JOptionPane.showInputDialog(this, "Enter a number: ", 0);

            try {

                number = Double.parseDouble(userResponse);

                canContinue = true;

            }

            catch (NumberFormatException e) {

                JOptionPane.showMessageDialog(this, "You must supply a valid number", "Error", JOptionPane.ERROR_MESSAGE);

                canContinue = false;

            }

        } while (!canContinue);

        JOptionPane.showMessageDialog(this, String.format("The entered number was: %8.2f", number), "App message", JOptionPane.INFORMATION_MESSAGE);

boolean canContinue = false;

        Integer number = 0;

        do {

            String userResponse = JOptionPane.showInputDialog(this, "Enter a number: ", 0);

            try {

                number = Integer.parseInt(userResponse);

                canContinue = true;

            }

            catch (NumberFormatException e) {

                JOptionPane.showMessageDialog(this, "You must supply a valid number", "Error", JOptionPane.ERROR_MESSAGE);

                canContinue = false;

            }

        } while (!canContinue);

        JOptionPane.showMessageDialog(this, String.format("The entered number was: %d", number), "App message", JOptionPane.INFORMATION_MESSAGE);