Java by API/javax.swing/SpinnerModel

SpinnerModel: addChangeListener(ChangeListener l)

import java.util.Calendar;
import javax.swing.JFrame;
import javax.swing.JLabel;
import javax.swing.JSpinner;
import javax.swing.SpinnerDateModel;
import javax.swing.SpinnerModel;
import javax.swing.event.ChangeEvent;
import javax.swing.event.ChangeListener;
public class MainClass {
  public static void main(String[] args) {
    JFrame frame = new JFrame();
    Calendar now = Calendar.getInstance();
    Calendar earliest = (Calendar) now.clone();
    earliest.add(Calendar.MONTH, -6);
    Calendar latest = (Calendar) now.clone();
    latest.add(Calendar.MONTH, 6);
    SpinnerModel model = new SpinnerDateModel(now.getTime(), earliest.getTime(), latest.getTime(),
        Calendar.WEEK_OF_YEAR);
    final JSpinner spinner = new JSpinner(model);
    model.addChangeListener(new ChangeListener() {
      public void stateChanged(ChangeEvent e) {
        System.out.println(((SpinnerDateModel) e.getSource()).getDate());
      }
    });
    frame.getContentPane().add("North", new JLabel("Choose a week"));
    frame.getContentPane().add("Center", spinner);
    frame.pack();
    frame.setDefaultCloseOperation(JFrame.EXIT_ON_CLOSE);
    frame.setVisible(true);
  }
}