JToolBar.setVisible(false) affects only buttons within the toolbar.. not
the toolbar itself... you have to force a redraw by draggin the frame to
make final effect appear...

run the following code on any text file and use the toggle button to toggle
the toolbar on/off and view the results on the frame... extend/contract
the frame border to view what the results should be... repaint calls to lazily
redraw the frame are useless...

run with: java textpane <filename>

import java.awt.*;
import java.io.*;
import java.beans.*;
import java.awt.event.*;
import com.sun.java.swing.*;
import com.sun.java.swing.event.*;
 
public class textpane extends JEditorPane implements ActionListener {
 
boolean ToolBarVisible = true;
 
JToolBar toolbar;
JScrollPane scroller;
JPanel panel;
JViewport vp;
 
        textpane () {
        super();
        scroller = new JScrollPane(ScrollPaneConstants.VERTICAL_SCROLLBAR_AS_NEE
DED,
                        ScrollPaneConstants.HORIZONTAL_SCROLLBAR_AS_NEEDED);
        vp = scroller.getViewport();
        vp.add(this);
        vp.setBackingStoreEnabled(true);
 
        panel = new JPanel();
        panel.setLayout(new BorderLayout());
        panel.add("North", this.EditorToolBar());
        panel.add("Center", scroller);
        panel.add("South", this.TestToolBar());
        }
 
        public JToolBar EditorToolBar() {
        toolbar = new JToolBar();
        JButton btn1 = new JButton("button");
        toolbar.add(btn1);
        return toolbar;
        }
 
        public JToolBar TestToolBar() {
 
        JToolBar testToolBar = new JToolBar();
        JButton visibletool = new JButton("Toggle toolbar on/off");
 
        visibletool.setToolTipText("Toggle ToolBar Visible");
        visibletool.setActionCommand("TBV");
        visibletool.addActionListener(this);
 
        testToolBar.add(visibletool);
        return testToolBar;
        }
     public void actionPerformed(ActionEvent Evt) {
 
                String cmd = Evt.getActionCommand();
 
                if("TBV".equals(cmd)) {
                setToolBarVisible(!getToolBarVisible());
                }
        }
 
        public void setToolBarVisible(boolean visible) {
                ToolBarVisible = visible;
                toolbar.setVisible(visible);
                repaint();
        }
 
        public boolean getToolBarVisible() {
                return ToolBarVisible;
        }
 
        public void OpenFile(String fileName) {
 
        Thread loader = new fileloader(fileName);
        loader.start();
 
        }
 
        class fileloader extends Thread {
        String file;
 
        fileloader(String myfile) {
                setPriority(3);
                file = myfile;
        }
 
        public void run() {
                File f = new File(file);
                try {
                Reader in = new FileReader(f);
                read(in, f);
                }
                catch (IOException e) {
                System.err.println(e.toString());
                }
            }
        }
  public static void main(String[] args) {
   try {
                UIManager myui = new UIManager();
           UIManager.setLookAndFeel(UIManager.getCrossPlatformLookAndFeelClassNa
me());
                //myui.setLookAndFeel(UIManager.getSystemLookAndFeelClassName())
;
        } catch (Exception exc) {
            System.err.println("Error loading L&F: " + exc);
        }
 
      textpane myeditor = new textpane();
      JFrame f = new JFrame("SAP: Text Editor");
      f.getContentPane().setLayout(new BorderLayout());
      f.getContentPane().add("Center", myeditor.panel);
      f.addWindowListener(new WindowAdapter() {
                public void windowClosing(WindowEvent e) {System.exit(0);}
        });
 
      f.pack();
      f.setSize(600, 400);
      f.setVisible(true);
 
      myeditor.setBackground(Color.white);
      myeditor.setFont(new Font("Courier", 0, 12));
      myeditor.OpenFile(args[0]);
   }
}