JList

import java.awt.*;

import javax.swing.*;
import javax.swing.tree.TreeNode;
import javax.swing.tree.TreePath;
import java.util.Enumeration;


public class JTreeTest extends JFrame {

    //增加带滚动条容器
    JScrollPane jScrollPane1 = new JScrollPane();

    //创建树对象
    JTree treeObj = new JTree();

    public JTreeTest () {
        try {
            jbInit();
        } catch (Exception exception) {
            exception.printStackTrace();
        }
    }

    private void jbInit() throws Exception {
        getContentPane().setLayout(null);
        setSize(new Dimension(434, 347));
        setTitle("JTree Test");
        jScrollPane1.setBounds(new Rectangle(9, 9, 429, 317));
        this.getContentPane().add(jScrollPane1);
        expandTree(treeObj);
        jScrollPane1.getViewport().add(treeObj);
        this.setVisible(true);
        this.setDefaultCloseOperation(JFrame.EXIT_ON_CLOSE);
    }

    /**完全展开一个JTree    
     * @param tree JTree
    */
    public static void expandTree(JTree tree) {
        TreeNode root = (TreeNode) tree.getModel().getRoot();
        expandAll(tree, new TreePath(root), true);
    }

    /**    
    * 完全展开或关闭一个树,用于递规执行    
     * @param tree JTree    
    * @param parent 父节点    
     * @param expand 为true则表示展开树,否则为关闭整棵树    
     */
    private static void expandAll(JTree tree, TreePath parent, boolean expand) {

        //Traverse children
        TreeNode node = (TreeNode) parent.
                        getLastPathComponent();
        if (node.getChildCount() >= 0) {
            for (Enumeration e = node.children(); e.hasMoreElements(); ) {
                TreeNode n = (TreeNode) e.nextElement();
                TreePath path = parent.pathByAddingChild(n);
                expandAll(tree, path, expand);
            }
        }

        if (expand) {
            tree.expandPath(parent);
        } else {
            tree.collapsePath(parent);
        }
    }
   
    public static void main(String[] args) {
// TODO Auto-generated method stub
SwingUtilities.invokeLater(new Runnable(){

@Override
public void run() {
// TODO Auto-generated method stub
  new JTreeTest();
}

});
}
}