Java中ToolBar的使用方法？

ToolBarAction???这是哪个类啊？JDK中有这个类吗？
全部改为JButton就可以了。import javax.swing.*;
import java.awt.event.*;
import java.awt.*;public class MainFrame extends JFrame
{
JDesktopPane desktop;
JMenuBar MBar;
JToolBar toolBar; public MainFrame()
{
super("MainFrame");
setBounds(100,100,600,400);
buildContent();
buildMenu();
buildToolBar(); this.getContentPane().add(toolBar,BorderLayout.NORTH); this.addWindowListener(new WindowAdapter() 
{
public void windowClosing(WindowEvent e)
{
System.exit(0);
}
});
} protected void buildContent()
{
desktop=new JDesktopPane();
getContentPane().add(desktop);
} protected void buildMenu()
{
MBar=new JMenuBar();
MBar.setOpaque(true);
JMenu mfile=buildFileMenu(); mfile.setMnemonic('F'); MBar.add(mfile);
setJMenuBar(MBar);
} protected void buildToolBar()
{
toolBar=new JToolBar();
toolBar.setFloatable(true);/*
ToolBarAction tba_new=new ToolBarAction("new",new ImageIcon("icons/new.jpg"));
ToolBarAction tba_open=new ToolBarAction("open",new ImageIcon("icons/open.jpg"));
ToolBarAction tba_close=new ToolBarAction("close",new ImageIcon("icons/close.jpg"));
ToolBarAction tba_save=new ToolBarAction("save",new ImageIcon("icons/save.jpg"));
*/
JButton tba_new=new JButton("New",new ImageIcon("icons/new.jpg"));
JButton tba_open=new JButton("Open",new ImageIcon("icons/open.jpg"));
JButton tba_close=new JButton("Close",new ImageIcon("icons/close.jpg"));
JButton tba_save=new JButton("Save",new ImageIcon("icons/save.jpg"));
JButton JB=null;

JB=tba_new;
toolBar.add(tba_new);
JB.setActionCommand("TB_NEW");
JB.setToolTipText(tba_new.getActionCommand());
JB.addActionListener(new ActionListener()
{
public void actionPerformed(ActionEvent e)
{
makeNewFrame();
}
});

JB=tba_open;
toolBar.add(tba_open);
JB.setActionCommand("TB_OPEN");
JB.setToolTipText((String)tba_open.getActionCommand());
JB.addActionListener(new ActionListener()
{
public void actionPerformed(ActionEvent e)
{
openDocument();
}
});



JB=tba_close;
toolBar.add(tba_close);
JB.setActionCommand("TB_CLOSE");
JB.setToolTipText((String)tba_close.getActionCommand());

JB=tba_save;
toolBar.add(tba_save);
JB.setActionCommand("TB_SAVE");
JB.setToolTipText((String)tba_save.getActionCommand()); } public JMenu buildFileMenu()
{
JMenu file=new JMenu("File");
JMenuItem newf=new JMenuItem("New");
JMenuItem open=new JMenuItem("Open");
JMenuItem close=new JMenuItem("Close");
JMenuItem quit=new JMenuItem("Exit"); close.setEnabled(false); newf.setMnemonic('N');
open.setMnemonic('O');
close.setMnemonic('C');
quit.setMnemonic('X'); newf.setAccelerator(KeyStroke.getKeyStroke('N',java.awt.Event.CTRL_MASK,false));
open.setAccelerator(KeyStroke.getKeyStroke('O',java.awt.Event.CTRL_MASK,false));
close.setAccelerator(KeyStroke.getKeyStroke('C',java.awt.Event.CTRL_MASK,false));
quit.setAccelerator(KeyStroke.getKeyStroke('X',java.awt.Event.CTRL_MASK,false)); newf.addActionListener(new ActionListener()
{
public void actionPerformed(ActionEvent e)
{
makeNewFrame();
}
}); open.addActionListener(new ActionListener()
{
public void actionPerformed(ActionEvent e)
{
openDocument();
}
}); quit.addActionListener(new ActionListener()
{
public void actionPerformed(ActionEvent e)
{
System.exit(0);
}
}); file.add(newf);
file.add(open);
file.add(close);
file.addSeparator();
file.add(quit); return file;
} public void makeNewFrame()
{
JInternalFrame JInew=new JInternalFrame("InternalForm",true,true,true,true);
JInew.setSize(new Dimension(300,200));
JInew.setLocation(20,20);

desktop.add(JInew,new Integer(1));
try
{
JInew.setVisible(true);
JInew.setSelected(true);
}
catch (java.beans.PropertyVetoException e2)
{
}
} public void openDocument()
{
JFileChooser chooser=new JFileChooser();
chooser.showOpenDialog(this);
}


public static void main(String[] args)
{
MainFrame mf=new MainFrame();
mf.setVisible(true);
mf.setDefaultCloseOperation(JFrame.EXIT_ON_CLOSE);
}
}