Display files also in tree?

Question

hai, to every one
This program displaying folders from the local system, But my problem is, it was not displaying files.
import java.awt.*;
import java.awt.event.*;
import java.io.*;
import java.util.*;
import javax.swing.*;
import javax.swing.tree.*;
import javax.swing.event.*;
public class FileTree1
  extends JFrame
  public static final ImageIcon ICON_COMPUTER =
    new ImageIcon("computer.gif");
  public static final ImageIcon ICON_DISK =
    new ImageIcon("disk.gif");
  public static final ImageIcon ICON_FOLDER =
    new ImageIcon("folder.gif");
  public static final ImageIcon ICON_EXPANDEDFOLDER =
    new ImageIcon("expandedfolder.gif");
  protected JTree  m_tree;
  protected DefaultTreeModel m_model;
  protected JTextField m_display;
  public FileTree1()
    super("Directories Tree");
    setSize(400, 300);
    DefaultMutableTreeNode top = new DefaultMutableTreeNode(
      new IconData(ICON_COMPUTER, null, "Computer"));
    DefaultMutableTreeNode node;
    File[] roots = File.listRoots();
    for (int k=0; k<roots.length; k++)
      node = new DefaultMutableTreeNode(new IconData(ICON_DISK,
        null, new FileNode(roots[k])));
      top.add(node);
                        node.add( new DefaultMutableTreeNode(new Boolean(true)));
    m_model = new DefaultTreeModel(top);
    m_tree = new JTree(m_model);
                m_tree.putClientProperty("JTree.lineStyle", "Angled");
    TreeCellRenderer renderer = new
      IconCellRenderer();
    m_tree.setCellRenderer(renderer);
    m_tree.addTreeExpansionListener(new
      DirExpansionListener());
    m_tree.addTreeSelectionListener(new
      DirSelectionListener());
    m_tree.getSelectionModel().setSelectionMode(
      TreeSelectionModel.SINGLE_TREE_SELECTION);
    m_tree.setShowsRootHandles(true);
    m_tree.setEditable(false);
    JScrollPane s = new JScrollPane();
    s.getViewport().add(m_tree);
    getContentPane().add(s, BorderLayout.CENTER);
    m_display = new JTextField();
    m_display.setEditable(false);
    getContentPane().add(m_display, BorderLayout.NORTH);
    WindowListener wndCloser = new WindowAdapter()
      public void windowClosing(WindowEvent e)
        System.exit(0);
    addWindowListener(wndCloser);
    setVisible(true);
  DefaultMutableTreeNode getTreeNode(TreePath path)
    return (DefaultMutableTreeNode)(path.getLastPathComponent());
  FileNode getFileNode(DefaultMutableTreeNode node)
    if (node == null)
      return null;
    Object obj = node.getUserObject();
    if (obj instanceof IconData)
      obj = ((IconData)obj).getObject();
    if (obj instanceof FileNode)
      return (FileNode)obj;
    else
      return null;
    // Make sure expansion is threaded and updating the tree model
    // only occurs within the event dispatching thread.
    class DirExpansionListener implements TreeExpansionListener
        public void treeExpanded(TreeExpansionEvent event)
            final DefaultMutableTreeNode node = getTreeNode(
                event.getPath());
            final FileNode fnode = getFileNode(node);
            Thread runner = new Thread()
              public void run()
                if (fnode != null && fnode.expand(node))
                  Runnable runnable = new Runnable()
                    public void run()
                       m_model.reload(node);
                  SwingUtilities.invokeLater(runnable);
            runner.start();
        public void treeCollapsed(TreeExpansionEvent event) {}
  class DirSelectionListener
    implements TreeSelectionListener
    public void valueChanged(TreeSelectionEvent event)
      DefaultMutableTreeNode node = getTreeNode(
        event.getPath());
      FileNode fnode = getFileNode(node);
      if (fnode != null)
        m_display.setText(fnode.getFile().
          getAbsolutePath());
      else
        m_display.setText("");
  public static void main(String argv[])
    new FileTree1();
class IconCellRenderer
  extends    JLabel
  implements TreeCellRenderer
  protected Color m_textSelectionColor;
  protected Color m_textNonSelectionColor;
  protected Color m_bkSelectionColor;
  protected Color m_bkNonSelectionColor;
  protected Color m_borderSelectionColor;
  protected boolean m_selected;
  public IconCellRenderer()
    super();
    m_textSelectionColor = UIManager.getColor(
      "Tree.selectionForeground");
    m_textNonSelectionColor = UIManager.getColor(
      "Tree.textForeground");
    m_bkSelectionColor = UIManager.getColor(
      "Tree.selectionBackground");
    m_bkNonSelectionColor = UIManager.getColor(
      "Tree.textBackground");
    m_borderSelectionColor = UIManager.getColor(
      "Tree.selectionBorderColor");
    setOpaque(false);
  public Component getTreeCellRendererComponent(JTree tree,
    Object value, boolean sel, boolean expanded, boolean leaf,
    int row, boolean hasFocus)
    DefaultMutableTreeNode node =
      (DefaultMutableTreeNode)value;
    Object obj = node.getUserObject();
    setText(obj.toString());
                if (obj instanceof Boolean)
                  setText("Retrieving data...");
    if (obj instanceof IconData)
      IconData idata = (IconData)obj;
      if (expanded)
        setIcon(idata.getExpandedIcon());
      else
        setIcon(idata.getIcon());
    else
      setIcon(null);
    setFont(tree.getFont());
    setForeground(sel ? m_textSelectionColor :
      m_textNonSelectionColor);
    setBackground(sel ? m_bkSelectionColor :
      m_bkNonSelectionColor);
    m_selected = sel;
    return this;
  public void paintComponent(Graphics g)
    Color bColor = getBackground();
    Icon icon = getIcon();
    g.setColor(bColor);
    int offset = 0;
    if(icon != null && getText() != null)
      offset = (icon.getIconWidth() + getIconTextGap());
    g.fillRect(offset, 0, getWidth() - 1 - offset,
      getHeight() - 1);
    if (m_selected)
      g.setColor(m_borderSelectionColor);
      g.drawRect(offset, 0, getWidth()-1-offset, getHeight()-1);
    super.paintComponent(g);
class IconData
  protected Icon   m_icon;
  protected Icon   m_expandedIcon;
  protected Object m_data;
  public IconData(Icon icon, Object data)
    m_icon = icon;
    m_expandedIcon = null;
    m_data = data;
  public IconData(Icon icon, Icon expandedIcon, Object data)
    m_icon = icon;
    m_expandedIcon = expandedIcon;
    m_data = data;
  public Icon getIcon()
    return m_icon;
  public Icon getExpandedIcon()
    return m_expandedIcon!=null ? m_expandedIcon : m_icon;
  public Object getObject()
    return m_data;
  public String toString()
    return m_data.toString();
class FileNode
  protected File m_file;
  public FileNode(File file)
    m_file = file;
  public File getFile()
    return m_file;
  public String toString()
    return m_file.getName().length() > 0 ? m_file.getName() :
      m_file.getPath();
  public boolean expand(DefaultMutableTreeNode parent)
    DefaultMutableTreeNode flag =
      (DefaultMutableTreeNode)parent.getFirstChild();
    if (flag==null)    // No flag
      return false;
    Object obj = flag.getUserObject();
    if (!(obj instanceof Boolean))
      return false;      // Already expanded
    parent.removeAllChildren();  // Remove Flag
    File[] files = listFiles();
    if (files == null)
      return true;
    Vector v = new Vector();
    for (int k=0; k<files.length; k++)
               /*File child = new File(dir, list);
          String name = (child.getName()) ;
          if(child.isDirectory()) add(new Node(child));
          else add(new Node(child));*/
File f = files[k];
if (!(f.isDirectory()))
continue;
FileNode newNode = new FileNode(f);
boolean isAdded = false;
for (int i=0; i<v.size(); i++)
FileNode nd = (FileNode)v.elementAt(i);
if (newNode.compareTo(nd) < 0)
v.insertElementAt(newNode, i);
isAdded = true;
break;
if (!isAdded)
v.addElement(newNode);
for (int i=0; i<v.size(); i++)
FileNode nd = (FileNode)v.elementAt(i);
IconData idata = new IconData(FileTree1.ICON_FOLDER,
FileTree1.ICON_EXPANDEDFOLDER, nd);
DefaultMutableTreeNode node = new
DefaultMutableTreeNode(idata);
parent.add(node);
if (nd.hasSubDirs())
node.add(new DefaultMutableTreeNode(
new Boolean(true) ));
return true;
public boolean hasSubDirs()
File[] files = listFiles();
if (files == null)
return false;
for (int k=0; k<files.length; k++)
if (files[k].isDirectory())
return true;
return false;
public int compareTo(FileNode toCompare)
return m_file.getName().compareToIgnoreCase(
toCompare.m_file.getName() );
protected File[] listFiles()
if (!m_file.isDirectory())
          return m_file.listFiles();
     try
return m_file.listFiles();
catch (Exception ex)
JOptionPane.showMessageDialog(null,
"Error reading directory "+m_file.getAbsolutePath(),
"Warning", JOptionPane.WARNING_MESSAGE);
return null;
Thanks in advance
raja

Answer 1

This code shows the files in your tree
import java.awt.*;
import java.awt.event.*;
import java.io.*;
import java.util.*;
import javax.swing.*;
import javax.swing.tree.*;
import javax.swing.event.*;
public class FileTree1
  extends JFrame
  public static final ImageIcon ICON_COMPUTER =
    new ImageIcon("computer.gif");
  public static final ImageIcon ICON_DISK =
    new ImageIcon("disk.gif");
  public static final ImageIcon ICON_FOLDER =
    new ImageIcon("folder.gif");
  public static final ImageIcon ICON_EXPANDEDFOLDER =
    new ImageIcon("expandedfolder.gif");
  protected JTree  m_tree;
  protected DefaultTreeModel m_model;
  protected JTextField m_display;
  public FileTree1()
    super("Directories Tree");
    setSize(400, 300);
    DefaultMutableTreeNode top = new DefaultMutableTreeNode(
      new IconData(ICON_COMPUTER, null, "Computer"));
    DefaultMutableTreeNode node;
    File[] roots = File.listRoots();
    for (int k=0; k<roots.length; k++)
      node = new DefaultMutableTreeNode(new IconData(ICON_DISK,
        null, new FileNode(roots[k])));
      top.add(node);
                        node.add( new DefaultMutableTreeNode(new Boolean(true)));
    m_model = new DefaultTreeModel(top);
    m_tree = new JTree(m_model);
                m_tree.putClientProperty("JTree.lineStyle", "Angled");
    TreeCellRenderer renderer = new
      IconCellRenderer();
    m_tree.setCellRenderer(renderer);
    m_tree.addTreeExpansionListener(new
      DirExpansionListener());
    m_tree.addTreeSelectionListener(new
      DirSelectionListener());
    m_tree.getSelectionModel().setSelectionMode(
      TreeSelectionModel.SINGLE_TREE_SELECTION);
    m_tree.setShowsRootHandles(true);
    m_tree.setEditable(false);
    JScrollPane s = new JScrollPane();
    s.getViewport().add(m_tree);
    getContentPane().add(s, BorderLayout.CENTER);
    m_display = new JTextField();
    m_display.setEditable(false);
    getContentPane().add(m_display, BorderLayout.NORTH);
    WindowListener wndCloser = new WindowAdapter()
      public void windowClosing(WindowEvent e)
        System.exit(0);
    addWindowListener(wndCloser);
    setVisible(true);
  DefaultMutableTreeNode getTreeNode(TreePath path)
    return (DefaultMutableTreeNode)(path.getLastPathComponent());
  FileNode getFileNode(DefaultMutableTreeNode node)
    if (node == null)
      return null;
    Object obj = node.getUserObject();
    if (obj instanceof IconData)
      obj = ((IconData)obj).getObject();
    if (obj instanceof FileNode)
      return (FileNode)obj;
    else
      return null;
    // Make sure expansion is threaded and updating the tree model
    // only occurs within the event dispatching thread.
    class DirExpansionListener implements TreeExpansionListener
        public void treeExpanded(TreeExpansionEvent event)
            final DefaultMutableTreeNode node = getTreeNode(
                event.getPath());
            final FileNode fnode = getFileNode(node);
            Thread runner = new Thread()
              public void run()
                if (fnode != null && fnode.expand(node))
                  Runnable runnable = new Runnable()
                    public void run()
                       m_model.reload(node);
                  SwingUtilities.invokeLater(runnable);
            runner.start();
        public void treeCollapsed(TreeExpansionEvent event) {}
  class DirSelectionListener
    implements TreeSelectionListener
    public void valueChanged(TreeSelectionEvent event)
      DefaultMutableTreeNode node = getTreeNode(
        event.getPath());
      FileNode fnode = getFileNode(node);
      if (fnode != null)
        m_display.setText(fnode.getFile().
          getAbsolutePath());
      else
        m_display.setText("");
  public static void main(String argv[])
    new FileTree1();
class IconCellRenderer
  extends    JLabel
  implements TreeCellRenderer
  protected Color m_textSelectionColor;
  protected Color m_textNonSelectionColor;
  protected Color m_bkSelectionColor;
  protected Color m_bkNonSelectionColor;
  protected Color m_borderSelectionColor;
  protected boolean m_selected;
  public IconCellRenderer()
    super();
    m_textSelectionColor = UIManager.getColor(
      "Tree.selectionForeground");
    m_textNonSelectionColor = UIManager.getColor(
      "Tree.textForeground");
    m_bkSelectionColor = UIManager.getColor(
      "Tree.selectionBackground");
    m_bkNonSelectionColor = UIManager.getColor(
      "Tree.textBackground");
    m_borderSelectionColor = UIManager.getColor(
      "Tree.selectionBorderColor");
    setOpaque(false);
  public Component getTreeCellRendererComponent(JTree tree,
    Object value, boolean sel, boolean expanded, boolean leaf,
    int row, boolean hasFocus)
    DefaultMutableTreeNode node =
      (DefaultMutableTreeNode)value;
    Object obj = node.getUserObject();
    setText(obj.toString());
                if (obj instanceof Boolean)
                  setText("Retrieving data...");
    if (obj instanceof IconData)
      IconData idata = (IconData)obj;
      if (expanded)
        setIcon(idata.getExpandedIcon());
      else
        setIcon(idata.getIcon());
    else
      setIcon(null);
    setFont(tree.getFont());
    setForeground(sel ? m_textSelectionColor :
      m_textNonSelectionColor);
    setBackground(sel ? m_bkSelectionColor :
      m_bkNonSelectionColor);
    m_selected = sel;
    return this;
  public void paintComponent(Graphics g)
    Color bColor = getBackground();
    Icon icon = getIcon();
    g.setColor(bColor);
    int offset = 0;
    if(icon != null && getText() != null)
      offset = (icon.getIconWidth() + getIconTextGap());
    g.fillRect(offset, 0, getWidth() - 1 - offset,
      getHeight() - 1);
    if (m_selected)
      g.setColor(m_borderSelectionColor);
      g.drawRect(offset, 0, getWidth()-1-offset, getHeight()-1);
    super.paintComponent(g);
class IconData
  protected Icon   m_icon;
  protected Icon   m_expandedIcon;
  protected Object m_data;
  public IconData(Icon icon, Object data)
    m_icon = icon;
    m_expandedIcon = null;
    m_data = data;
  public IconData(Icon icon, Icon expandedIcon, Object data)
    m_icon = icon;
    m_expandedIcon = expandedIcon;
    m_data = data;
  public Icon getIcon()
    return m_icon;
  public Icon getExpandedIcon()
    return m_expandedIcon!=null ? m_expandedIcon : m_icon;
  public Object getObject()
    return m_data;
  public String toString()
    return m_data.toString();
class FileNode
  protected File m_file;
  public FileNode(File file)
    m_file = file;
  public File getFile()
    return m_file;
  public String toString()
    return m_file.getName().length() > 0 ? m_file.getName() :
      m_file.getPath();
  public boolean expand(DefaultMutableTreeNode parent)
    DefaultMutableTreeNode flag =
      (DefaultMutableTreeNode)parent.getFirstChild();
    if (flag==null)    // No flag
      return false;
    Object obj = flag.getUserObject();
    if (!(obj instanceof Boolean))
      return false;      // Already expanded
    parent.removeAllChildren();  // Remove Flag
    File[] files = listFiles();
    if (files == null)
      return true;
    Vector v = new Vector();
    for (int k=0; k<files.length; k++)
               File child = new File(dir, list);
          String name = (child.getName()) ;
          if(child.isDirectory()) add(new Node(child));
          else add(new Node(child));
File f = files[k];
/* if (!(f.isDirectory()))
continue; */
FileNode newNode = new FileNode(f);
boolean isAdded = false;
for (int i=0; i><v.size(); i++)
FileNode nd = (FileNode)v.elementAt(i);
if (newNode.compareTo(nd) >< 0)
v.insertElementAt(newNode, i);
isAdded = true;
break;
if (!isAdded)
v.addElement(newNode);
for (int i=0; i<v.size(); i++)
FileNode nd = (FileNode)v.elementAt(i);
IconData idata = new IconData(FileTree1.ICON_FOLDER,
FileTree1.ICON_EXPANDEDFOLDER, nd);
DefaultMutableTreeNode node = new
DefaultMutableTreeNode(idata);
parent.add(node);
if (nd.hasSubDirs())
node.add(new DefaultMutableTreeNode(
new Boolean(true) ));
return true;
public boolean hasSubDirs()
File[] files = listFiles();
if (files == null)
return false;
for (int k=0; k><files.length; k++)
if (true)
return true;
return false;
public int compareTo(FileNode toCompare)
return m_file.getName().compareToIgnoreCase(
toCompare.m_file.getName() );
protected File[] listFiles()
if (!m_file.isDirectory())
          return m_file.listFiles();
     try
return m_file.listFiles();
catch (Exception ex)
JOptionPane.showMessageDialog(null,
"Error reading directory "+m_file.getAbsolutePath(),
"Warning", JOptionPane.WARNING_MESSAGE);
return null;