JOptionPane or JFrame returning value from JCalendar

Is it possible to return a value from JFrame or JOptionPane in which I have Jcalendar from Flib? JCalendar need own Listener class. And i have this:

 org.freixas.jcalendar.JCalendar jd = new org.freixas.jcalendar.JCalendar(org.freixas.jcalendar.JCalendar.DISPLAY_DATE | org.freixas.jcalendar.JCalendar.DISPLAY_TIME,true);
    KalendarPanel kalendar = new KalendarPanel();
    String message = "Choose start date:\n";
    Object[] params = {message, jd};
   JOptionPane.showConfirmDialog(null, params, "Start date", JOptionPane.PLAIN_MESSAGE);

But i dont know how to add Listener class and how return value from JOptionPane. In JFrame i can add class listener but i dont know how to return value to parent JFrame. JFrame code:

public class Kalendar extends javax.swing.JFrame {

private Calendar date;
private SimpleDateFormat sdf = new SimpleDateFormat("YYYY-MM-dd HH:MM:ss");
private String datum;


public Kalendar() {
    initComponents();
    jCalendar1.addDateListener(new MyDateListener());
}  

/**
 * This method is called from within the constructor to initialize the form.
 * WARNING: Do NOT modify this code. The content of this method is always
 * regenerated by the Form Editor.
 */
@SuppressWarnings("unchecked")
// <editor-fold defaultstate="collapsed" desc="Generated Code">                          
private void initComponents() {

    jCalendar1 = new org.freixas.jcalendar.JCalendar();

    setDefaultCloseOperation(javax.swing.WindowConstants.EXIT_ON_CLOSE);

    javax.swing.GroupLayout layout = new javax.swing.GroupLayout(getContentPane());
    getContentPane().setLayout(layout);
    layout.setHorizontalGroup(
        layout.createParallelGroup(javax.swing.GroupLayout.Alignment.LEADING)
        .addComponent(jCalendar1, javax.swing.GroupLayout.PREFERRED_SIZE, 315, javax.swing.GroupLayout.PREFERRED_SIZE)
    );
    layout.setVerticalGroup(
        layout.createParallelGroup(javax.swing.GroupLayout.Alignment.LEADING)
        .addComponent(jCalendar1, javax.swing.GroupLayout.PREFERRED_SIZE, 188, javax.swing.GroupLayout.PREFERRED_SIZE)
    );

    pack();
}// </editor-fold>                        


// Variables declaration - do not modify                     
private org.freixas.jcalendar.JCalendar jCalendar1;
// End of variables declaration                   

class MyDateListener implements DateListener {

    @Override
    public void dateChanged(DateEvent e) {
        datum = sdf.format(e.getSelectedDate().getTime());
    }
}

Thank you very much.

Here is a solution for you. I hope you can use this approach for your component (JCalendar).

import javax.swing.JList;
import javax.swing.JOptionPane;
import javax.swing.JScrollPane;
import javax.swing.SwingUtilities;
import javax.swing.event.ListSelectionEvent;
import javax.swing.event.ListSelectionListener;

public class ListOptionTest {

    public static void main(String[] args) {
        SwingUtilities.invokeLater(new Runnable() {

            @Override
            public void run() {
                String[] data = new String[10];
                for (int i = 0; i < 10; i++) {
                    data[i] = "Item " + (i + 1);
                }
                final JList<String> list = new JList<>(data);
                list.addListSelectionListener(new ListSelectionListener() {

                    @Override
                    public void valueChanged(ListSelectionEvent e) {
                        if (!e.getValueIsAdjusting()) {
                            System.out.println("Current selection: " + list.getSelectedValuesList());
                        }
                    }
                });
                int result = JOptionPane.showConfirmDialog(null, new JScrollPane(list), "Make your choice",
                        JOptionPane.OK_CANCEL_OPTION);
                if (result == JOptionPane.OK_OPTION) {
                    System.out.println("Final selection: " + list.getSelectedValuesList());
                } else {
                    System.out.println("No choice");
                }
            }
        });
    }
}