Java ActionEvent is alt key pressed

import java.awt.event.ActionEvent;
import java.awt.event.ActionListener;
import java.text.DateFormat;
import java.util.Calendar;
import java.util.Date;
import java.util.Locale;

import javax.swing.JButton;
import javax.swing.JFrame;

public class Main {
  public static void main(String[] args) {
    JFrame f = new JFrame();
    JButton ok = new JButton("Ok");

    ok.addActionListener(new ActionListener() {
      public void actionPerformed(ActionEvent event) {
        Calendar cal = Calendar.getInstance();
        cal.setTimeInMillis(event.getWhen());
        System.out.println(cal.getTime());

        if (event.getID() == ActionEvent.ACTION_PERFORMED)
          System.out.println(" Event Id: ACTION_PERFORMED");

        String source = event.getSource().getClass().getName();
        System.out.println(" Source: " + source);

        int mod = event.getModifiers();
        if ((mod & ActionEvent.ALT_MASK) > 0)
          System.out.println("Alt ");

        if ((mod & ActionEvent.SHIFT_MASK) > 0)
          System.out.println("Shift ");

        if ((mod & ActionEvent.META_MASK) > 0)
          System.out.println("Meta ");

        if ((mod & ActionEvent.CTRL_MASK) > 0)
          System.out.println("Ctrl ");

      }/*w w  w .j av  a  2s  .co m*/
    });

    f.add(ok);

    f.setSize(420, 250);
    f.setLocationRelativeTo(null);
    f.setDefaultCloseOperation(JFrame.EXIT_ON_CLOSE);
    f.setVisible(true);
  }
}