JTree - changed content, refresh

Question

Hello,
I have a problem in my program I can`t solve...
basically I am using drop-down menu with different drives (c:, d:, etc.). Don`t ask me why I don`t use the JTree to display all the drives, I simply need to display each drive separately.
when I select the drive, JTree pops up with the content of the drive.
Problem comes in, when the JTree is already displayed and I go into my drop-down menu to select a different drive.... Everything seems to work fine in background.... The tree gets build up, I just somehow cannot update (or refresh) the screen....
did anyone experienced similar problem?
thank you
Otakar

Answer 1

No, I am not using TreeModel.. Let me post the code... I am using 3 different files:
MainModule.java
DetectDrives.java
FileSystem.java
I think You might wanna see the ChoiceListener in MainModule
thank you for you time
MainModule.java
import javax.swing.*;
import javax.swing.event.*;
import javax.swing.tree.DefaultMutableTreeNode;
import java.awt.*;
import java.awt.event.*;
public class MainModule{
     private JFrame aFrame;         // BASE frame
     private JPanel driveListPane;
     private JList  driveList;
     // MENU Bar Components
     private JMenuBar aMenuBar;
     private JMenu fileMenu, editMenu, viewMenu, settingsMenu, helpMenu;
     private JMenuItem newMenuItem, openMenuItem, saveMenuItem,                // FILE menu Items
                                       saveAsMenuItem, exitMenuItem,                     //
                                       selectDriveMenuItem, selectOutputMenuItem;        // SETTINGS menu Items
      // ComboBox
     private JComboBox aComboBox;
      // Buttons
     private JButton selectDriveButton, printButton;
     // Listeners
     private PrintButtonListener prtListener;
     private ChoiceListener choiceListener;
     // Labels
     private JLabel sourceLabel, label1, label2;
     private int listRows;
     public static String drive;
     private DetectDrives dd;
     private FileSystem fs;
     private int ct;
     /*============ CONSTRUCTOR ===========================================================\
     |
     public MainModule(){
         ct = 0;
          // create a MAIN WINDOW (Frame)
          drive = new String("C:\\");
          aFrame = new JFrame("Otax Drive Printer 0.99b");
          aFrame.setSize(800, 600);
          aFrame.setLocation(100, 50);
          aFrame.getContentPane().setLayout(null);
          aFrame.setDefaultCloseOperation(JFrame.EXIT_ON_CLOSE);
          // create the categories in a menu bar
          aMenuBar = new JMenuBar();
          fileMenu = new JMenu("File");
          editMenu = new JMenu("Edit");
          viewMenu = new JMenu("View");
          settingsMenu = new JMenu("Settings");
          helpMenu = new JMenu("Help");
          // create menu items for FILE menu
          newMenuItem = new JMenuItem("New", 'N');
          openMenuItem = new JMenuItem( "Open", 'O');
          saveMenuItem = new JMenuItem( "Save", 'S' );
                 saveAsMenuItem = new JMenuItem( "Save As", 'A');
                 exitMenuItem = new JMenuItem("Exit", 'E');
          // create menu items for SETTINGS menu
                 selectDriveMenuItem = new JMenuItem("Select Drive", 'D');
                 selectOutputMenuItem = new JMenuItem("Select Output", 'O');
          // detect drives mounted to system and put them into JComboBox
          dd = new DetectDrives();
          aComboBox = new JComboBox(dd.detectCdDrives());
          aComboBox.setBounds(100, 5, 180, 20);
          //create labels
          sourceLabel = new JLabel("Select Source:");
          sourceLabel.setBounds(6, 4, 90, 20);
                 label1 = new JLabel("Current Drive: ");
          label1.setBounds(2, 500, 90, 20);
          label2 = new JLabel();
          label2.setBounds(85, 500, 50, 20);
          //create buttons
          printButton = new JButton("Print");
          printButton.setBounds(2, 50, 101, 16);
                 //create Accelerators for FILE MenuItems
                 newMenuItem.setAccelerator(KeyStroke.getKeyStroke(
               KeyEvent.VK_N, InputEvent.CTRL_MASK, false));
          saveMenuItem.setAccelerator(KeyStroke.getKeyStroke(
               KeyEvent.VK_S, InputEvent.CTRL_MASK, false));
          //create the action listeners (listener definitions bellow)
          prtListener = new PrintButtonListener();
          choiceListener = new ChoiceListener();
          //connect the action listeners with menu items
          printButton.addActionListener(prtListener);
          aComboBox.addActionListener(choiceListener);
     // LISTENERS Definitions start HERE ====================================
     public class PrintButtonListener implements ActionListener{
          public void actionPerformed(ActionEvent e){
               System.out.println("print action performed: " + drive);
     public class ChoiceListener implements ActionListener{
         public void actionPerformed( ActionEvent e)
              ct++;
              System.out.println(ct + " event started");
           String drive = new String(aComboBox.getSelectedItem().toString().substring(0,2));
           label2.setText(drive);
           fs = new FileSystem(drive + "//");
           fs.sortFiles();
           fs.addNodes(drive);
           DefaultMutableTreeNode top = fs.getNodes();
           JTree tree = new JTree(top);
           tree.setBounds(10, 30, 500, 450);
              aFrame.getContentPane().add(tree);
           aFrame.repaint();
     public void addComponents(){
          aMenuBar.add(fileMenu);        // create menu
          aMenuBar.add(editMenu);
          aMenuBar.add(settingsMenu);
          aMenuBar.add(helpMenu);
          fileMenu.add(newMenuItem);     //add items to the FILE menu
          fileMenu.add(openMenuItem);
          fileMenu.addSeparator();
          fileMenu.add(saveMenuItem);
                 fileMenu.add(saveAsMenuItem);
                 fileMenu.addSeparator();
                 fileMenu.add(exitMenuItem);
          settingsMenu.add(selectDriveMenuItem);
          settingsMenu.add(selectOutputMenuItem);
          aFrame.setJMenuBar(aMenuBar);
          aFrame.getContentPane().add(aComboBox);
          aFrame.getContentPane().add(sourceLabel);
          aFrame.getContentPane().add(label1);
          aFrame.getContentPane().add(label2);
          aFrame.setVisible(true);
     public static void main(String [] args){
          MainModule m1 = new MainModule();
          m1.addComponents();
DetectDrives.java
import java.io.*;
import java.util.Vector;
import javax.swing.filechooser.*;
public class DetectDrives{
     private FileSystemView fsv;
     private File[] roots;
     private Vector drives;
     /*======== CONSTRUCTOR =====================================================================\
     |Purpose: To INITIALIZE the object                                                          |
     |Variables: (FileSystemView) fsv - creates the Object containing info about current system  |
     |           (File[]) roots - array used to store all drives currently mounted to system     |
     |           (Vector) drives - vector used for storage of selected info about drives         |
       \==========================================================================================*/
     public DetectDrives(){
          drives = new Vector(0,1); // *Create empty Vector(0) with expansion capacity (1)
          //--- Get a FileSystemView object for the current system
         fsv = FileSystemView.getFileSystemView();
        //--- Get an array of File objects describing the 'roots' attached to the system
          roots = File.listRoots();
     /*SD1)==== Method detectCdDrives() ========================================================\
     |Purpose: To SCAN the system for any drives mounted and add DRIVE LETTER and DRIVE NAME    |
     |         to a Vector. It Also CHECKS if drive CONTAINS any DATA or if it`s EMPTY.         |
     |Variables: (int) i - a loop iterator                                                      |
     |           (String) cdInfo - temporary storage for drive information during drive check   |
     |           (Vector) drives - storage for driveletter and drive name for all drives        |
     |                             This Vector is returned upon function call                   |
     public Vector detectCdDrives(){
          String cdInfo;
          //SCAN system and RETRIEVE drives
          for(int i = 0; i < roots.length; i++){
               if((fsv.getSystemDisplayName(roots)).equals("")) //--FIND OUT if any DATA on DRIVE
                    cdInfo = fsv.getSystemTypeDescription(roots[i]) + " ";
               else
               cdInfo = fsv.getSystemDisplayName(roots[i]);
               drives.addElement(roots[i].getPath() + " " + cdInfo.substring(0, cdInfo.length()-5));
          return drives;
FileSystem.java
import javax.swing.*;
import javax.swing.event.*;
import javax.swing.tree.*;
import javax.swing.tree.DefaultMutableTreeNode;
import java.io.File;
import java.io.*;
import java.util.Vector;
public class FileSystem{
     private String driveLetter;
     private Vector root;
     private Vector dirs;
     private Vector files;
     private File dir;
     private File [] allFiles;
     private DefaultMutableTreeNode top;
     /*================= File System Constructor ================================\
     |Purpose: To initialize the conject and to accept drive letter selected in  |
     |         main module                                                       |
     public FileSystem(String dl){
          driveLetter = dl;
    /*================= Method: sortFiles() ====================================\
     |Purpose: To sort content of selected drive, directories (alphabetically),  |
     |         followed by files (alphabeticaly)                                 |
     public void sortFiles(){
          dir = new File (driveLetter);
          allFiles = dir.listFiles();
          root  = new Vector(2,1);
          dirs  = new Vector(0,1);
         files = new Vector(0,1);
         //---- Separate Directories and Files into 2 different vectors
         for(int i = 0; i < allFiles.length; i++){
               if(allFiles.isDirectory())
               dirs.add(allFiles[i]);
               else
               files.add(allFiles[i]);
          //---- Add elements from dirs and files Vectors into root vector
          for(int i = 0; i < dirs.size(); i++){
               root.add(dirs.elementAt(i));
          for(int i = 0; i < files.size(); i++){
               root.add(files.elementAt(i));
/*================= Method: addNodes() =====================================\
     |Purpose: to build the file structure which will be used to create the tree |
     |Variables: drive = used to accept the drive letter representing the root |
     | top = primary (root) node in the structure) |
| root = vector of all files in the drive |
     public void addNodes(String drive){
          top = new DefaultMutableTreeNode(drive);
          DefaultMutableTreeNode node = null;
          for(int i = 0; i < root.size(); i++){
               node = new DefaultMutableTreeNode(root.elementAt(i));
               top.add(node);
/*================= Method: getNodes() =====================================\
     |Purpose: To return variable top, which holds the files structure and will |
     | be used to build the tree |
public DefaultMutableTreeNode getNodes(){
          return top;