package 树组件;

import java.awt.Component;

public class Example9_12 {

public static void main(String args[]){

TreeWin win=new TreeWin();

win.setTitle("树组件");

}

}

package 树组件;

import java.awt.*;

import java.awt.event.*;

import javax.swing.*;

import javax.swing.event.*;

import javax.swing.tree.*;

public class TreeWin extends JFrame implements TreeSelectionListener,ActionListener{

JTree tree;

JTextArea showText;

TreeWin(){

setLayout(new FlowLayout());

DefaultMutableTreeNode root=new DefaultMutableTreeNode("商品");

DefaultMutableTreeNode nodeTV=new DefaultMutableTreeNode("电视机类");

DefaultMutableTreeNode nodePhone=new DefaultMutableTreeNode("手机类");

DefaultMutableTreeNode tv1=new DefaultMutableTreeNode(new Goods("长虹电视",5699));

DefaultMutableTreeNode tv2=new DefaultMutableTreeNode(new Goods("海尔电视",7832));

DefaultMutableTreeNode phone1=new DefaultMutableTreeNode(new Goods("诺基亚手机",7320));

DefaultMutableTreeNode phone2=new DefaultMutableTreeNode(new Goods("小米手机",7882));

DefaultMutableTreeNode phone3=new DefaultMutableTreeNode(new Goods("三星手机",7302));

root.add(nodeTV);

root.add(nodePhone);

nodeTV.add(tv1);

nodeTV.add(tv2);

nodePhone.add(phone1);

nodePhone.add(phone2);

nodePhone.add(phone3);

tree=new JTree(root);

tree.addTreeSelectionListener(this);

showText=new JTextArea();

setLayout(new GridLayout(1,3));

add(new JScrollPane(tree));

add(new JScrollPane(showText));

JButton button=new JButton("确定");

add(button);

button.addActionListener(this);

setDefaultCloseOperation(JFrame.EXIT_ON_CLOSE);

setVisible(true);

setBounds(80,80,300,300);

validate();

}

public void actionPerformed(ActionEvent e){

int n=JOptionPane.showConfirmDialog(this, "确定要关闭吗？","确认对话框",JOptionPane.YES_NO_CANCEL_OPTION);

if(n==JOptionPane.YES_OPTION){

dispose();

}

}

public void valueChanged(TreeSelectionEvent e){

DefaultMutableTreeNode node=(DefaultMutableTreeNode)tree.getLastSelectedPathComponent();

if(node.isLeaf()){

Goods s=(Goods)node.getUserObject();

showText.append(s.name+","+s.price+"元\n");

}

else

showText.setText(null);

}

}

package 树组件;

public class Goods {

String name;

double price;

Goods(String n,double s){

name=n;

price=s;

}

public String toString(){

return name;

}

}

这是运行结果：