JTree, JList and file selection

Question

I have a file selection JPanel that I'm creating that has a JTree on the left representing folders and a JList on the right that should have the files and folders listed to be able to select. I have two problems at this point. First, and more important, when a folder is selected, the JList doesn't update to the files in the new folder and I don't see what's keeping it from working. Second, when clicking on a folder in the JTree, it drops the folder to the end of the list and then lets you expand it to the other folders, also it shows the whole folder path instead of just the folder name.
This is still my first venture into JTrees and JLists and I'm still really new at JPanel and anything GUI, so my code may not make the most sense, but right now I'm just trying to get it to work.
Thank you.
public class FileSelection extends JFrame{
          Container gcp = getContentPane();
          File dir=new File("c:/");
          private JList fileList;
          JTree tree;
          DefaultMutableTreeNode folders;
          String filePath,selectedFile="", path;
          TreePath selPath;
          FileListPanel fileLP;
          FolderListPanel folderLP;
          JScrollPane listScroller;
          public FileSelection(String name){
               super(name);
               gcp.setLayout(new BorderLayout());
               fileLP = new FileListPanel();
               folderLP = new FolderListPanel();
               gcp.add(fileLP, BorderLayout.CENTER);
               gcp.add(folderLP, BorderLayout.WEST);
               setVisible(true);
          private class FileListPanel extends JPanel implements ActionListener{
               public FileListPanel(){
                    final JButton selectItem = new JButton("Select");
                    final JButton cancel = new JButton("Cancel");
                    final JButton changeDir = new JButton("Change Directory");
                    //add buttons
                    add(selectItem);
                    add(changeDir);
                    add(cancel);
                    //instantiate buttons
                    selectItem.setActionCommand("SelectItem");
                    selectItem.addActionListener(this);
                    changeDir.setActionCommand("ChangeDirectory");
                    changeDir.addActionListener(this);
                    cancel.setActionCommand("Cancel");
                    cancel.addActionListener(this);
                    final String[] fileArr=dir.list();
                    fileList = new JList(fileArr);
                    fileList.setSelectionMode(ListSelectionModel.SINGLE_INTERVAL_SELECTION);
                    fileList.setLayoutOrientation(JList.VERTICAL_WRAP);
                    fileList.setVisible(true);
                    fileList.setVisibleRowCount(-1);
                    fileList.setSelectedIndex(0);
                    listScroller = new JScrollPane(fileList);
                    listScroller.setPreferredSize(new Dimension(200,200));
                    listScroller.setAlignmentX(LEFT_ALIGNMENT);
                    add(listScroller);
                    MouseListener mouseListener = new MouseAdapter(){
                         public void mouseClicked(MouseEvent e){
                              if(e.getClickCount()==2){
                                   int itemIndex = fileList.locationToIndex(e.getPoint());
                                   currFile=fileArr[itemIndex];
                                   dispose();
                    fileList.addMouseListener(mouseListener);
               public void actionPerformed(ActionEvent e){
                    if("SelectItem".equals(e.getActionCommand())){
                         currFile=(String)fileList.getSelectedValue();
                         dispose();
                    }else{
                    if("Cancel".equals(e.getActionCommand())){
                         dispose();
                    }else{
                    if("ChangeDirectory".equals(e.getActionCommand())){
                         ChangeDir cd = new ChangeDir("Select Directory");
                         cd.setSize(new Dimension(300,275));
                         cd.setLocation(500, 225);
          private class FolderListPanel extends JPanel{
               public FolderListPanel(){
                    String[] files = dir.list();
                    DefaultMutableTreeNode topNode = new DefaultMutableTreeNode("Files");
                    folders = new DefaultMutableTreeNode("C:/");
                    topNode.add(folders);
                    folders = getFolders(dir, folders);
                    tree = new JTree(topNode);
                    tree.setVisible(true);
                    JScrollPane treeScroller = new JScrollPane(tree);
                    treeScroller.setPreferredSize(new Dimension(500,233));
                    treeScroller.setAlignmentX(LEFT_ALIGNMENT);
                    add(treeScroller);
                    MouseListener mouseListener = new MouseAdapter(){
                         public void mouseClicked(MouseEvent e){
                              try{
                                   if(e.getClickCount()==1){
                                        selPath = tree.getPathForLocation(e.getX(), e.getY());
                                        path=selPath.getLastPathComponent().toString();
                                        dir = new File(path);
                                        TreeNode tn=findNode(folders, path);                    
                                        if(tn!=null){
                                             folders.add((MutableTreeNode) getTreeNode(dir, (DefaultMutableTreeNode) tn));
                                        tree.updateUI();
                                        final String[] fileArr=dir.list();
                                        fileList = new JList(fileArr);
                                        fileList.updateUI();
                                        listScroller.updateUI();
                                        fileLP = new FileListPanel();
                              }catch(NullPointerException npe){
                    tree.addMouseListener(mouseListener);
               public DefaultMutableTreeNode getFolders(File dir, DefaultMutableTreeNode folders){
                    File[] folderList = dir.listFiles();
                    int check=0;
                    for(int x=0;x<folderList.length;x++){
                         if(folderList[x].isDirectory()){
                              folders.add(new DefaultMutableTreeNode(folderList[x]));               
                    return folders;
               public TreeNode getTreeNode(File dir, DefaultMutableTreeNode folders){
                    File[] folderList = dir.listFiles();
                    int check=0;
                    for(int x=0;x<folderList.length;x++){
                         if(folderList[x].isDirectory()){
                              folders.add(new DefaultMutableTreeNode(folderList[x]));               
                    return folders;
               public TreeNode findNode(DefaultMutableTreeNode folders, String node){
                    Enumeration children = folders.postorderEnumeration();
                    Object current;
                    while(children.hasMoreElements()){
                         current = children.nextElement();
                         if(current.toString().equals(node)){
                              return (TreeNode)current;
                    return null;
     }

Answer 1

Wow! I changed the FolderListPanel's mouseListener to:
tree.addTreeSelectionListener(new TreeSelectionListener(){
                         public void valueChanged(TreeSelectionEvent tse){
                              DefaultMutableTreeNode node = (DefaultMutableTreeNode)tree.getLastSelectedPathComponent();
                              if(node==null)return;
                              Object nodeInfo = node.getUserObject();
                              dir=new File(nodeInfo.toString());
                              folders.add((MutableTreeNode) getFolders(dir,node));
                    });and it's amazing how much better the tree is!!! But I still don't have the JList part working. I changed the JList and the FileListPanel to public from private, but that didn't change anything.