Java JMenu(Action a) Constructor

public JMenu(Action a)

import java.awt.event.ActionEvent;
/*from  ww  w  .j ava 2  s. c  o  m*/
import javax.swing.AbstractAction;
import javax.swing.JFrame;
import javax.swing.JLabel;
import javax.swing.JMenu;
import javax.swing.JMenuBar;
import javax.swing.JMenuItem;
import javax.swing.JSeparator;

public class Main extends JFrame {
  public Main() {
    setDefaultCloseOperation(JFrame.EXIT_ON_CLOSE);
    JMenuBar bar = new JMenuBar();
    JMenu menu = new JMenu(new AbstractAction("File"){

      @Override
      public void actionPerformed(ActionEvent arg0) {
         System.out.println("action");
        
      }
      
    });
    bar.add(menu);

    menu.add(new JMenuItem("Close"));
    menu.add(new JSeparator()); // SEPARATOR
    menu.add(new AbstractAction("Exit"){

      @Override
      public void actionPerformed(ActionEvent arg0) {
         System.out.println("action");
        
      }
      
    });

    setJMenuBar(bar);
    add(new JLabel("A placeholder"));

    pack();
    setSize(300, 300);
    setVisible(true);
  }

  public static void main(String arg[]) {
    new Main();
  }
}