Swing程序题：用JTree创建一个节点树，当鼠标点节点时会弹出一个框来显示当前子节点的信息。

import javax.swing.JFrame;

import javax.swing.JOptionPane;

import javax.swing.JScrollPane;

import javax.swing.JTree;

import javax.swing.ScrollPaneConstants;

import javax.swing.UIManager;

import javax.swing.UnsupportedLookAndFeelException;

import javax.swing.event.TreeSelectionEvent;

import javax.swing.event.TreeSelectionListener;

import javax.swing.tree.DefaultMutableTreeNode;

import javax.swing.tree.DefaultTreeModel;

/**

 * 

 * @author 逝水

 *

 */

public class JTreeDemo extends JFrame implements TreeSelectionListener{

private static final long serialVersionUID = -6209666185329417356L;

//树组件

protected JTree jTree ;

public JTreeDemo(){

init();

}

//初始化

private void init() {

jTree =  new JTree();

//树节点的相关数据

DefaultMutableTreeNode root = new DefaultMutableTreeNode("三国名将");

DefaultMutableTreeNode shu = new DefaultMutableTreeNode("蜀国");

DefaultMutableTreeNode wei = new DefaultMutableTreeNode("魏国");

DefaultMutableTreeNode wu = new DefaultMutableTreeNode("吴国");

shu.add(new DefaultMutableTreeNode("关羽"));

shu.add(new DefaultMutableTreeNode("张飞"));

shu.add(new DefaultMutableTreeNode("赵云"));

shu.add(new DefaultMutableTreeNode("马超"));

shu.add(new DefaultMutableTreeNode("黄忠"));

wei.add(new DefaultMutableTreeNode("张辽"));

wei.add(new DefaultMutableTreeNode("典韦"));

wei.add(new DefaultMutableTreeNode("夏侯惇"));

wei.add(new DefaultMutableTreeNode("许褚"));

wei.add(new DefaultMutableTreeNode("徐晃"));

wu.add(new DefaultMutableTreeNode("太史慈"));

wu.add(new DefaultMutableTreeNode("甘宁"));

wu.add(new DefaultMutableTreeNode("孙策"));

wu.add(new DefaultMutableTreeNode("周瑜"));

wu.add(new DefaultMutableTreeNode("陆逊"));

root.add(shu);

root.add(wei);

root.add(wu);

//树的数据模型

DefaultTreeModel model = new DefaultTreeModel(root);

//设置数据模型

jTree.setModel(model);

// 展开所有树

for (int i = 0; i < jTree.getRowCount(); i++)

jTree.expandRow(i);

//添加事件

jTree.addTreeSelectionListener(this);

//滚动面板

JScrollPane jScrollPane = new JScrollPane(jTree,

ScrollPaneConstants.VERTICAL_SCROLLBAR_ALWAYS,

ScrollPaneConstants.HORIZONTAL_SCROLLBAR_NEVER);

//添加树到滚动面板

jScrollPane.getViewport().add(jTree);

//添加滚动面板到窗口中

this.getContentPane().add(jScrollPane);

this.setTitle("JTree的事件例子");

this.pack();

this.setDefaultCloseOperation(JFrame.EXIT_ON_CLOSE);

}

public static void main(String[] args){

//Windows风格

//String lookAndFeel = "com.sun.java.swing.plaf.windows.WindowsLookAndFeel";

//Windows Classic风格

//String lookAndFeel = "com.sun.java.swing.plaf.windows.WindowsClassicLookAndFeel";

//系统当前风格

String lookAndFeel = UIManager.getSystemLookAndFeelClassName();

try {

UIManager.setLookAndFeel(lookAndFeel);

} catch (ClassNotFoundException e) {

e.printStackTrace();

} catch (InstantiationException e) {

e.printStackTrace();

} catch (IllegalAccessException e) {

e.printStackTrace();

} catch (UnsupportedLookAndFeelException e) {

e.printStackTrace();

}

JTreeDemo demo = new JTreeDemo();

demo.setVisible(true);

}

@Override

public void valueChanged(TreeSelectionEvent e) {

//获取选择的节点

DefaultMutableTreeNode node = (DefaultMutableTreeNode) jTree

.getLastSelectedPathComponent();

if(node.getLevel() == 0){

//显示提示信息

JOptionPane.showMessageDialog(null, 

node.getUserObject()+": 共"+node.getChildCount()+"个国家");

}else if(node.getLevel() == 1){

//显示提示信息

JOptionPane.showMessageDialog(null, 

node.getUserObject()+": 共"+node.getChildCount()+"名名将");

}else if(node.getLevel() == 2){

//显示提示信息

JOptionPane.showMessageDialog(null, node.getParent()+"名将: "+

node.getUserObject());

}

}

}

两位做得都很不错，学习了

觉得第二个更接近提问者想要的，如果能变点节点选择后，再出对话框就更好了。

兄弟你看看，能否让你满意
import java.awt.GridLayout;

import javax.swing.JEditorPane;
import javax.swing.JFrame;
import javax.swing.JPanel;
import javax.swing.JScrollPane;
import javax.swing.JTree;
import javax.swing.SwingUtilities;
import javax.swing.UIManager;
import javax.swing.event.TreeSelectionEvent;
import javax.swing.event.TreeSelectionListener;
import javax.swing.tree.DefaultMutableTreeNode;
import javax.swing.tree.TreeSelectionModel;

public class TreeDemo1 extends JFrame implements TreeSelectionListener {

private static final long serialVersionUID = 1L;
private JPanel jContentPane = null;
private JTree jTree = null;
private JEditorPane jEditorPane = null;
private JScrollPane jScrollPane = null;

public JScrollPane getjScrollPane() {
if(jScrollPane==null){
jScrollPane = new JScrollPane();
jScrollPane.setViewportView(getJTree());
}
return jScrollPane;
}

DefaultMutableTreeNode top = null; // @jve:decl-index=0:

/**
* This is the default constructor
*/
public TreeDemo1() {
super();
initialize();
}

/**
* This method initializes this
*
* @return void
*/
private void initialize() {
this.setSize(438, 309);
this.setDefaultCloseOperation(JFrame.EXIT_ON_CLOSE);
this.setContentPane(getJContentPane());
this.setTitle("JFrame");
}

/**
* This method initializes jContentPane
*
* @return javax.swing.JPanel
*/
private JPanel getJContentPane() {
if (jContentPane == null) {
GridLayout gridLayout = new GridLayout();
gridLayout.setRows(1);
gridLayout.setColumns(2);
jContentPane = new JPanel();
jContentPane.setLayout(gridLayout);
jContentPane.add(getjScrollPane(), null);
jContentPane.add(getJEditorPane(), null);
}
return jContentPane;
}

/**
* This method initializes jTree
*
* @return javax.swing.JTree
*/
private JTree getJTree() {
if (jTree == null) {
top = new DefaultMutableTreeNode("黄山");
createNodes(top);
jTree = new JTree(top);
jTree.getSelectionModel().setSelectionMode(
TreeSelectionModel.SINGLE_TREE_SELECTION);
jTree.addTreeSelectionListener(this);

}
return jTree;
}

private void createNodes(DefaultMutableTreeNode top) {
DefaultMutableTreeNode jingdian = null, jiaotong = null, zhusu = null, binguan = null, luying = null, jiesu = null;
jingdian = new DefaultMutableTreeNode("景点");
jingdian.add(new DefaultMutableTreeNode("景点1"));
jingdian.add(new DefaultMutableTreeNode("景点2"));
jiaotong = new DefaultMutableTreeNode("交通");
jiaotong.add(new DefaultMutableTreeNode("路线1"));
jiaotong.add(new DefaultMutableTreeNode("路线2"));
jiaotong.add(new DefaultMutableTreeNode("路线3"));
zhusu = new DefaultMutableTreeNode("住宿");
zhusu.add(new DefaultMutableTreeNode("A住宿"));
zhusu.add(new DefaultMutableTreeNode("B住宿"));
zhusu.add(new DefaultMutableTreeNode("C住宿"));

binguan = new DefaultMutableTreeNode("宾馆");
binguan.add(new DefaultMutableTreeNode("X宾馆"));
binguan.add(new DefaultMutableTreeNode("Y宾馆"));
binguan.add(new DefaultMutableTreeNode("Z宾馆"));
binguan.add(new DefaultMutableTreeNode("XYZ宾馆"));
luying = new DefaultMutableTreeNode("露营");
luying.add(new DefaultMutableTreeNode("方式1"));
luying.add(new DefaultMutableTreeNode("方式2"));
jiesu = new DefaultMutableTreeNode("借宿");
jiesu.add(new DefaultMutableTreeNode("借宿1"));
jiesu.add(new DefaultMutableTreeNode("借宿2"));
jiesu.add(new DefaultMutableTreeNode("借宿3"));
top.add(jingdian);
top.add(jiaotong);
top.add(zhusu);
top.add(binguan);
top.add(luying);
top.add(jiesu);
}

/**
* This method initializes jEditorPane
*
* @return javax.swing.JEditorPane
*/
private JEditorPane getJEditorPane() {
if (jEditorPane == null) {
jEditorPane = new JEditorPane();
}
return jEditorPane;
}

@Override
public void valueChanged(TreeSelectionEvent e) {
DefaultMutableTreeNode node = (DefaultMutableTreeNode) jTree
.getLastSelectedPathComponent();

if (node == null)
// Nothing is selected.
return;
if(node.isRoot()){
jEditorPane.setText("黄山的简介");
}
}

public static void main(String[] args) {
SwingUtilities.invokeLater(new Runnable() {

@Override
public void run() {

try {
UIManager.setLookAndFeel(UIManager.getSystemLookAndFeelClassName());
}catch(Exception e){
e.printStackTrace();
}
new TreeDemo1().setVisible(true);
}
});
}

}