How can I display the tooltip in a tree node?

Question

I implement a TreeCellRenderer and has already set the tooltiptext through the following code:
    public Component getTreeCellRendererComponent(JTree tree, Object value,
                           boolean selected, boolean expanded,
                           boolean leaf, int row,
                              boolean hasFocus) {
        Object userObject = ((DefaultMutableTreeNode)value).getUserObject();
        if(Leaf.class.isInstance(userObject)) {
                Leaf leaf = (Leaf)userObject;
                setToolTipText(leaf.getString());
    }Why can't the tree display the tooltip when a move the mouse on the leaf of the tree?
Thank you!

Answer 1

import java.awt.*;
import java.awt.event.*;
import javax.swing.*;
import javax.swing.tree.*;
public class Test3 extends JFrame {
public Test3() {
setDefaultCloseOperation(JFrame.EXIT_ON_CLOSE);
Container content = getContentPane();
JTree jt = new JTree() {
public String getToolTipText(MouseEvent evt) {
if (getRowForLocation(evt.getX(), evt.getY()) == -1)
return null;
TreePath curPath = getPathForLocation(evt.getX(),
evt.getY());
return curPath.getLastPathComponent().toString();
content.add(new JScrollPane(jt), BorderLayout.CENTER);
jt.setToolTipText("");
setSize(400, 400);
setVisible(true);
public static void main(String[] args) { new Test3();
}It sounds a solution. I use the following code and also can display the tooltip,but there's also a problem:
    mytree.setCellRenderer(new MyTreeCellRenderer());
    ToolTipManager.sharedInstance().registerComponent(mytree);the above code only effective when the function getTreeCellRendererComponent in MyTreeCellRenderer like the following:
    public Component getTreeCellRendererComponent(JTree tree, Object value,
                           boolean selected, boolean expanded,
                           boolean leaf, int row,
                              boolean hasFocus) {
     String  stringValue = tree.convertValueToText(value, selected,
                            expanded, leaf, row, hasFocus);
     setText(stringValue);
     setToolTipText(stringValue); //Tooltips used by the tree
     /* Set the icon of the node */
                     Object userObject = ((DefaultMutableTreeNode)value).getUserObject();
     if(Device.class.isInstance(userObject)) {
         setIcon(deviceIcon);
     } else {
         setIcon(nullIcon);
         Business b = (Business)userObject;
     setFont(defaultFont);
     /* Update the selected flag for the next paint. */
     this.selected = selected;
     this.hasFocus = hasFocus;
     if(selected) // && hasFocus)
         setForeground(Color.white);
     else
         setForeground(Color.black);
     return this;
    }but when the code is bellow,it displays nothing(Only the leaf node need tooltip):
    public Component getTreeCellRendererComponent(JTree tree, Object value,
                           boolean selected, boolean expanded,
                           boolean leaf, int row,
                              boolean hasFocus) {
     String  stringValue = tree.convertValueToText(value, selected,
                            expanded, leaf, row, hasFocus);
     setText(stringValue);
     //setToolTipText(stringValue); //Tooltips used by the tree
     /* Set the icon of the node */
                     Object userObject = ((DefaultMutableTreeNode)value).getUserObject();
                     if(Device.class.isInstance(userObject)) {
         setIcon(deviceIcon);
     } else {
         setIcon(nullIcon);
         Business b = (Business)userObject;
         if(b.isShowOrder())
             setToolTipText(b.getContaId());  // only some node need tooltip, not all  node
     setFont(defaultFont);
     /* Update the selected flag for the next paint. */
     this.selected = selected;
     this.hasFocus = hasFocus;
     if(selected) // && hasFocus)
         setForeground(Color.white);
     else
         setForeground(Color.black);
     return this;
    }Anyone knows why?