学步园

如果想改变节点显示效果，可以通过设置setCellRenderer方法来实现。

例子：这个例子是同继承DefaultTreeCellRenderer类，重写getTreeCellRendererComponent方法来改变节点显示方式

public class AnimatedIconTreeExample extends JFrame {   
  
  public AnimatedIconTreeExample() {   
    super("AnimatedIconTreeExample");   
    String[] strs = { "CARNIVORA", // 0   
        "Felidae", // 1   
        "Acinonyx jutatus  (cheetah)", // 2   
        "Panthera leo  (lion)", // 3   
        "Canidae", // 4   
        "Canis lupus  (wolf)", // 5   
        "Lycaon pictus  (lycaon)", // 6   
        "Vulpes Vulpes  (fox)" }; // 7   
  
    IconNode[] nodes = new IconNode[strs.length];   
    for (int i = 0; i < strs.length; i++) {   
      nodes[i] = new IconNode(strs[i]);   
    }   
    nodes[0].add(nodes[1]);   
    nodes[0].add(nodes[4]);   
    nodes[1].add(nodes[2]);   
    nodes[1].add(nodes[3]);   
    nodes[4].add(nodes[5]);   
    nodes[4].add(nodes[6]);   
    nodes[4].add(nodes[7]);   
  
    nodes[2].setIcon(new ImageIcon("title4.gif"));   
    nodes[3].setIcon(new ImageIcon("title4.gif"));   
    nodes[5].setIcon(new ImageIcon("title4.gif"));   
    nodes[6].setIcon(new ImageIcon("title4.gif"));   
    nodes[7].setIcon(new ImageIcon("title4.gif"));   
  
    JTree tree = new JTree(nodes[0]);   
    tree.setCellRenderer(new IconNodeRenderer());   
    setImageObserver(tree, nodes);   
  
    JScrollPane sp = new JScrollPane(tree);   
    getContentPane().add(sp, BorderLayout.CENTER);   
  }   
  
  private void setImageObserver(JTree tree, IconNode[] nodes) {   
    for (int i = 0; i < nodes.length; i++) {   
      ImageIcon icon = (ImageIcon) nodes[i].getIcon();   
      if (icon != null) {   
        icon.setImageObserver(new NodeImageObserver(tree, nodes[i]));   
      }   
    }   
  }   
  
  class NodeImageObserver implements ImageObserver {   
    JTree tree;   
  
    DefaultTreeModel model;   
  
    TreeNode node;   
  
    NodeImageObserver(JTree tree, TreeNode node) {   
      this.tree = tree;   
      this.model = (DefaultTreeModel) tree.getModel();   
      this.node = node;   
    }   
  
    public boolean imageUpdate(Image img, int flags, int x, int y, int w,   
        int h) {   
      if ((flags & (FRAMEBITS | ALLBITS)) != 0) {   
        TreePath path = new TreePath(model.getPathToRoot(node));   
        Rectangle rect = tree.getPathBounds(path);   
        if (rect != null) {   
          tree.repaint(rect);   
        }   
      }   
      return (flags & (ALLBITS | ABORT)) == 0;   
    }   
  }   
  
  public static void main(String args[]) {   
    try {   
        UIManager.setLookAndFeel("com.sun.java.swing.plaf.windows.WindowsLookAndFeel");   
    } catch (Exception evt) {}   
  
    AnimatedIconTreeExample frame = new AnimatedIconTreeExample();   
    frame.addWindowListener(new WindowAdapter() {   
      public void windowClosing(WindowEvent e) {   
        System.exit(0);   
      }   
    });   
    frame.setSize(280, 200);   
    frame.setVisible(true);   
  }   
}   
  
class IconNodeRenderer extends DefaultTreeCellRenderer {   
  
  public Component getTreeCellRendererComponent(JTree tree, Object value,   
      boolean sel, boolean expanded, boolean leaf, int row,   
      boolean hasFocus) {   
  
    super.getTreeCellRendererComponent(tree, value, sel, expanded, leaf,   
        row, hasFocus);   
  
    Icon icon = ((IconNode) value).getIcon();   
  
    if (icon == null) {   
      Hashtable icons = (Hashtable) tree.getClientProperty("title4.gif");   
      String name = ((IconNode) value).getIconName();   
      if ((icons != null) && (name != null)) {   
        icon = (Icon) icons.get(name);   
        if (icon != null) {   
          setIcon(icon);   
        }   
      }   
    } else {   
      setIcon(icon);   
    }   
  
    return this;   
  }   
}   
  
class IconNode extends DefaultMutableTreeNode {   
  
  protected Icon icon;   
  
  protected String iconName;   
  
  public IconNode() {   
    this(null);   
  }   
  
  public IconNode(Object userObject) {   
    this(userObject, true, null);   
  }   
  
  public IconNode(Object userObject, boolean allowsChildren, Icon icon) {   
    super(userObject, allowsChildren);   
    this.icon = icon;   
  }   
  
  public void setIcon(Icon icon) {   
    this.icon = icon;   
  }   
  
  public Icon getIcon() {   
    return icon;   
  }   
  
  public String getIconName() {   
    if (iconName != null) {   
      return iconName;   
    } else {   
      String str = userObject.toString();   
      int index = str.lastIndexOf(".");   
      if (index != -1) {   
        return str.substring(++index);   
      } else {   
        return null;   
      }   
    }   
  }   
  
  public void setIconName(String name) {   
    iconName = name;   
  }   
  
}