java 实现树形结构

package tree;

import java.awt.BorderLayout;
import java.awt.Color;
import java.awt.Font;
import java.awt.Image;

import javax.swing.ImageIcon;
import javax.swing.JFrame;
import javax.swing.JLabel;
import javax.swing.JScrollPane;
import javax.swing.JTree;
import javax.swing.event.TreeSelectionEvent;
import javax.swing.event.TreeSelectionListener;
import javax.swing.tree.DefaultMutableTreeNode;
import javax.swing.tree.DefaultTreeCellRenderer;
import javax.swing.tree.DefaultTreeModel;
import javax.swing.tree.TreeSelectionModel;

public class treenode extends JFrame implements TreeSelectionListener{

    JLabel jl;
public treenode()
     {
super("树形结构");

//创建根节点和子节点
        DefaultMutableTreeNode root=new DefaultMutableTreeNode("文本编辑器");


        DefaultMutableTreeNode node1=new DefaultMutableTreeNode("文件");
        DefaultMutableTreeNode node2=new DefaultMutableTreeNode("编辑");

//利用根节点创建treemodel
        DefaultTreeModel treemodel=new DefaultTreeModel(root);
//插入子节点
        treemodel.insertNodeInto(node1, root, root.getChildCount());
        treemodel.insertNodeInto(node2, root, root.getChildCount());

//创建node1的子节点并插入
        DefaultMutableTreeNode leafnode=new DefaultMutableTreeNode("打开");
        treemodel.insertNodeInto(leafnode, node1, node1.getChildCount());

        leafnode=new DefaultMutableTreeNode("保存");
        treemodel.insertNodeInto(leafnode, node1, node1.getChildCount());

        leafnode=new DefaultMutableTreeNode("另存为");
        treemodel.insertNodeInto(leafnode, node1, node1.getChildCount());

        leafnode=new DefaultMutableTreeNode("关闭");
        treemodel.insertNodeInto(leafnode, node1, node1.getChildCount());

//创建node2的子节点并插入
        leafnode=new DefaultMutableTreeNode("剪切");
        treemodel.insertNodeInto(leafnode, node2, node2.getChildCount());

        leafnode=new DefaultMutableTreeNode("复制");
        treemodel.insertNodeInto(leafnode, node2, node2.getChildCount());

        leafnode=new DefaultMutableTreeNode("粘贴");
        treemodel.insertNodeInto(leafnode, node2, node2.getChildCount());

//创建树对象
        JTree tree =new JTree(treemodel);

        tree.getSelectionModel().setSelectionMode(TreeSelectionModel.SINGLE_TREE_SELECTION);
        tree.addTreeSelectionListener(this);
        tree.setRowHeight(20);

//创建节点绘制对象
        DefaultTreeCellRenderer cell=(DefaultTreeCellRenderer)tree.getCellRenderer();

//设置字体
        cell.setFont(new Font("Serif",Font.PLAIN,14));
        cell.setBackgroundNonSelectionColor(Color.white);
        cell.setBackgroundSelectionColor(Color.LIGHT_GRAY);
        cell.setForeground(Color.red);

        cell.setIcon(new ImageIcon("/image/folder.jpg"));


//设置选中和不选中时文字的变化颜色
        cell.setTextNonSelectionColor(Color.black);
        cell.setTextNonSelectionColor(Color.black);


this.add(new JScrollPane(tree));



         jl=new JLabel("你当前选择的节点为：",JLabel.CENTER);
        jl.setFont(new Font("Serif",Font.PLAIN,14));
this.add(jl,BorderLayout.SOUTH);
this.setSize(400, 400);
this.setVisible(true);
this.setDefaultCloseOperation(JFrame.EXIT_ON_CLOSE);


     }


public static void main(String[] args) {
// TODO Auto-generated method stub
        treenode t=new treenode();
    }


    @Override
public void valueChanged(TreeSelectionEvent e) {
// TODO Auto-generated method stub
        
        JTree tree=(JTree)e.getSource();

//获取当前选中的节点
        DefaultMutableTreeNode selectnode=(DefaultMutableTreeNode)tree.getLastSelectedPathComponent();
        String nodename=selectnode.toString();

        jl.setText("您当前选择的节点为："+nodename);




    }

}