Hinzufügen jdatepicker in jpanel

Ich versuche, fügen Sie jdatepicker in jpanel, dieses jpanel ist aufgerufen, in jframe, das problem ist, dass wenn ich versuche, um jdatepicker direkt in jpanel wird nicht angezeigt, bis einige event ausgeführt wird.

Habe ich versucht diese Lösung, aber das war keine Hilfe. Wenn ich diese auch öffnen eines weiteren Fensters mit keine Daten.

und andere Methode, die ich verwende, ist -

Klasse MainApp, die im frame

public class MainApp extends JFrame implements ActionListener {

private JPanel panel;

private JMenuBar m_menuBar;
private JMenu m_menuSales;

private JMenuItem m_itmSalesNewBuisness;
private JMenuItem m_itmSalesAppointments;

private static MainApp instance = null;

public static MainApp getInstance() {
    if(instance == null) {
        instance = new MainApp();
    }

    return instance;
}

private MainApp() {
    initComponents();
}

private void initComponents() {
    this.setDefaultCloseOperation(JFrame.EXIT_ON_CLOSE);

    m_menuBar = new JMenuBar();
    m_menuSales = new JMenu("Sales");
    m_itmSalesAppointments = new JMenuItem("Appointments");
    m_itmSalesAppointments.addActionListener(this);
    m_itmSalesNewBuisness = new JMenuItem("New Business");
    m_itmSalesNewBuisness.addActionListener(this);

    m_menuBar.add(m_menuSales);
    setJMenuBar(m_menuBar);

    setSize(1300, 700);
    setVisible(true);
}

public static void main(String[] args) {
    try {
        UIManager.setLookAndFeel("javax.swing.plaf.metal.MetalLookAndFeel");
    } catch (UnsupportedLookAndFeelException ex) {
        ex.printStackTrace();
    } catch (IllegalAccessException ex) {
        ex.printStackTrace();
    } catch (InstantiationException ex) {
        ex.printStackTrace();
    } catch (ClassNotFoundException ex) {
        ex.printStackTrace();
    }
    UIManager.put("swing.boldMetal", Boolean.FALSE);

    SwingUtilities.invokeLater(new Runnable() {
        @Override
        public void run() {
            new MainApp();
        }
    });
}

@Override
public void actionPerformed(ActionEvent e) {
    if(m_itmSalesNewBuisness == e.getSource()){
        if(panel != null) {
            remove(panel);
            invalidate();
        }
        revalidate();
        repaint();
        panel = new CopyOfNewBusiness();
        panel.setBounds(0, 0, getWidth(), getHeight());
        add(panel);
    } else if(m_itmSalesAppointments == e.getSource()){
        if(panel != null) {
            remove(panel);
            invalidate();
        }
        revalidate();
        repaint();
        panel = new AppointmentTracker();
        panel.setBounds(0, 0, getWidth(), getHeight());
        add(panel);
    }
}

public JDatePickerImpl setDatePicker() {
    UtilDateModel model = new UtilDateModel();
    model.setSelected(true);
    JDatePanelImpl datePanel = new JDatePanelImpl(model);
    JDatePickerImpl datePicker = new JDatePickerImpl(datePanel, new DateLabelFormatter());
    return datePicker;      
}

NewBusiness.java

public class CopyOfNewBusiness extends JPanel implements ActionListener, ItemListener {

private JLabel m_lblDate;
private JDatePickerImpl m_dtpDate;

private JLabel m_lblFollowUpDate;
private UtilDateModel followUpDateModel;
private JDatePanelImpl followUpDatePanel;
private JDatePickerImpl m_dtpFollowUp;

public CopyOfNewBusiness() {
    initComponents();
}

private void initComponents() {
    setLayout(null);

    m_lblDate = new JLabel("Date");
    m_lblDate.setBounds(10, 10, 100, 30);
    add(m_lblDate);

    m_dtpDate = MainApp.getInstance().setDatePicker();
    m_dtpDate.setBounds(120, 10, 120, 30);
    add(m_dtpDate);

    m_lblFollowUpDate = new JLabel("Follow Up Date");
    m_lblFollowUpDate.setBounds(10, 370, 100, 30);
    add(m_lblFollowUpDate);

    followUpDateModel = new UtilDateModel();
    followUpDatePanel = new JDatePanelImpl(followUpDateModel);
    m_dtpFollowUp = new JDatePickerImpl(followUpDatePanel);
    m_dtpFollowUp.setBounds(120, 370, 120, 30);
    add(m_dtpFollowUp);

    setPreferredSize(new Dimension(getWidth(), getHeight()));
}

}