对话框要求编号

Question

创建要求编号的对话框的最佳方法是什么？并避免用户可以输入字母或将对话框留空的情况？ 我写了这样的东西，但我认为它可以改进：

private int giveInt(String message)
{
    int result =0;
    boolean successful = false;
    String[] options = {"OK"};
    JPanel panel = new JPanel();
    JLabel lbl = new JLabel(message);
    JTextField txt = new JTextField(10);
    panel.add(lbl);
    panel.add(txt);
    do{
        try {
            int selectedOption = JOptionPane.showOptionDialog(null, panel,
                    "Enter number", JOptionPane.NO_OPTION, JOptionPane.QUESTION_MESSAGE, 
                    null, options , options[0]);
            if(selectedOption == 0)
            {
                String input= txt.getText();
                if(input!=null)
                {
                    result = Integer.parseInt(input);
                    successful = true;
                }
                else result=0;
            }
        } catch (InputMismatchException ime) {
            JOptionPane.showMessageDialog(null, "Please enter an number");
        } catch (NumberFormatException nfe) {
            JOptionPane.showMessageDialog(null, "Please enter an number");
        }
    }while (!successful);

    return result;
}