Jmenubar, como faço para criar funcões em meus botões?

package Documents;

import java.awt.event.KeyEvent;
import java.awt.event.ActionListener;
import java.awt.event.ActionEvent;
import java.awt.Event;
import java.awt.BorderLayout;
import javax.swing.SwingConstants;
import javax.swing.SwingUtilities;
import javax.swing.KeyStroke;
import java.awt.Point;
import javax.swing.JLabel;
import javax.swing.JPanel;
import javax.swing.JMenuItem;
import javax.swing.JMenuBar;
import javax.swing.JMenu;
import javax.swing.JFrame;
import javax.swing.JDialog;

public class TempErros {

	private JFrame jFrame = null;

	private JPanel jContentPane = null;

	private JMenuBar jJMenuBar = null;

	private JMenu fileMenu = null;

	private JMenu editMenu = null;

	private JMenu helpMenu = null;

	private JMenuItem exitMenuItem = null;

	private JMenuItem aboutMenuItem = null;

	private JMenuItem cutMenuItem = null;

	private JMenuItem copyMenuItem = null;

	private JMenuItem pasteMenuItem = null;

	private JMenuItem saveMenuItem = null;

	
	private JFrame getJFrame() {
		if (jFrame == null) {
			jFrame = new JFrame();
			jFrame.setDefaultCloseOperation(JFrame.EXIT_ON_CLOSE);
			jFrame.setJMenuBar(getJJMenuBar());
			jFrame.setSize(300, 200);
			jFrame.setContentPane(getJContentPane());
			jFrame.setTitle("Application");
		}
		return jFrame;
	}

	
	private JPanel getJContentPane() {
		if (jContentPane == null) {
			jContentPane = new JPanel();
			jContentPane.setLayout(new BorderLayout());
		}
		return jContentPane;
	}

	private JMenuBar getJJMenuBar() {
		if (jJMenuBar == null) {
			jJMenuBar = new JMenuBar();
			jJMenuBar.add(getFileMenu());
			jJMenuBar.add(getEditMenu());
			jJMenuBar.add(getHelpMenu());
		}
		return jJMenuBar;
	}

	
	private JMenu getFileMenu() {
		if (fileMenu == null) {
			fileMenu = new JMenu();
			fileMenu.setText("Arquivos");
			fileMenu.add(getSaveMenuItem());
			fileMenu.add(getExitMenuItem());
		}
		return fileMenu;
	}

	
	private JMenu getEditMenu() {
		if (editMenu == null) {
			editMenu = new JMenu();
			editMenu.setText("Editar");
			editMenu.add(getCutMenuItem());
			editMenu.add(getCopyMenuItem());
			editMenu.add(getPasteMenuItem());
		}
		return editMenu;
	}

	
	private JMenu getHelpMenu() {
		if (helpMenu == null) {
			helpMenu = new JMenu();
			helpMenu.setText("Help");
			helpMenu.add(getAboutMenuItem());
		}
		return helpMenu;
	}

	
	private JMenuItem getExitMenuItem() {
		if (exitMenuItem == null) {
			exitMenuItem = new JMenuItem();
			exitMenuItem.setText("Exit");
			exitMenuItem.addActionListener(new ActionListener() {
				public void actionPerformed(ActionEvent e) {
					System.exit(0);
				}
			});
		}
		return exitMenuItem;
	}

	
	private JMenuItem getAboutMenuItem() {
		if (aboutMenuItem == null) {
			aboutMenuItem = new JMenuItem();
			aboutMenuItem.setText("About");
			aboutMenuItem.addActionListener(new ActionListener() {
				public void actionPerformed(ActionEvent e) {
					JDialog aboutDialog = getAboutDialog();
					aboutDialog.pack();
					Point loc = getJFrame().getLocation();
					loc.translate(20, 20);
					aboutDialog.setLocation(loc);
					aboutDialog.setVisible(true);
				}
			});
		}
		return aboutMenuItem;
	}

	
	private JMenuItem getCutMenuItem() {
		if (cutMenuItem == null) {
			cutMenuItem = new JMenuItem();
			cutMenuItem.setText("Cut");
			cutMenuItem.setAccelerator(KeyStroke.getKeyStroke(KeyEvent.VK_X,
					Event.CTRL_MASK, true));
		}
		return cutMenuItem;
	}

	
	private JMenuItem getCopyMenuItem() {
		if (copyMenuItem == null) {
			copyMenuItem = new JMenuItem();
			copyMenuItem.setText("Copy");
			copyMenuItem.setAccelerator(KeyStroke.getKeyStroke(KeyEvent.VK_C,
					Event.CTRL_MASK, true));
		}
		return copyMenuItem;
	}

	
	private JMenuItem getPasteMenuItem() {
		if (pasteMenuItem == null) {
			pasteMenuItem = new JMenuItem();
			pasteMenuItem.setText("Paste");
			pasteMenuItem.setAccelerator(KeyStroke.getKeyStroke(KeyEvent.VK_V,
					Event.CTRL_MASK, true));
		}
		return pasteMenuItem;
	}

	
	private JMenuItem getSaveMenuItem() {
		if (saveMenuItem == null) {
			saveMenuItem = new JMenuItem();
			saveMenuItem.setText("Save");
			saveMenuItem.setAccelerator(KeyStroke.getKeyStroke(KeyEvent.VK_S,
					Event.CTRL_MASK, true));
		}
		return saveMenuItem;
	}

	
	public static void main(String[] args) {
		SwingUtilities.invokeLater(new Runnable() {
			public void run() {
				TempErros application = new TempErros();
				application.getJFrame().setVisible(true);
			}
		});
	}

}