Java AbstractAction.getKeys()

public Object [] getKeys()

/*w ww  .  j  a  va2s .  c  om*/
import java.awt.BorderLayout;
import java.awt.event.ActionEvent;
import java.awt.event.InputEvent;
import java.awt.event.KeyEvent;

import javax.swing.AbstractAction;
import javax.swing.Action;
import javax.swing.JButton;
import javax.swing.JFrame;
import javax.swing.JMenu;
import javax.swing.JMenuBar;
import javax.swing.JMenuItem;
import javax.swing.KeyStroke;

public class Main {
  public static void main(String args[]) {
    JFrame frame = new JFrame();
    frame.setDefaultCloseOperation(JFrame.EXIT_ON_CLOSE);
    final Action printAction = new PrintHelloAction();

    JMenuBar menuBar = new JMenuBar();
    JMenu menu = new JMenu("File");
    menuBar.add(menu);
    JMenuItem menuItem = new JMenuItem("Print");
    KeyStroke ctrlP = KeyStroke.getKeyStroke(KeyEvent.VK_P,
        InputEvent.CTRL_MASK);
    menuItem.setAccelerator(ctrlP);
    menuItem.addActionListener(printAction);
    menu.add(menuItem);

    JButton fileButton = new JButton("About");
    fileButton.setMnemonic(KeyEvent.VK_A);
    fileButton.addActionListener(printAction);

    frame.setJMenuBar(menuBar);

    frame.add(fileButton, BorderLayout.SOUTH);
    frame.setSize(300, 100);
    frame.setVisible(true);
  }
}

class PrintHelloAction extends AbstractAction {

  PrintHelloAction() {
    super("Print");
    putValue(Action.SHORT_DESCRIPTION, "Hello, World");
    Object[] keys = super.getKeys();
    for(Object o:keys){
      System.out.println(o);
    }
  }

  public void actionPerformed(ActionEvent actionEvent) {
    System.out.println("Hello, World");
  }
}