用Java程序编写记事本

import java.awt.*;
import java.awt.event.*;
import javax.swing.*;
import java.io.*;

public class Notepad extends JFrame {

// 系统组件声明
private JMenuBar menuBar = new JMenuBar();
private JEditorPane content = new JEditorPane();
private JScrollPane scroll = new JScrollPane(content);
private JFileChooser filechooser = new JFileChooser() ;
private BorderLayout bord = new BorderLayout();
private JLabel statusBar = new JLabel();
private JPanel pane = new JPanel();
private File file = null;

// 定义文件菜单
private JMenu fileMenu = new JMenu();
private JMenuItem newMenuItem = new JMenuItem();
private JMenuItem openMenuItem = new JMenuItem();
private JMenuItem saveMenuItem = new JMenuItem();
private JMenuItem saveAsMenuItem = new JMenuItem();
private JMenuItem pageSetupMenuItem = new JMenuItem();
private JMenuItem printMenuItem = new JMenuItem();
private JMenuItem exitMenuItem = new JMenuItem();
// 定义风格菜单
private JMenu styleMenu = new JMenu();
private ButtonGroup styleMenuGroup = new ButtonGroup();
private JRadioButtonMenuItem javaStyleMenuItem = new JRadioButtonMenuItem();
private JRadioButtonMenuItem metalStyleMenuItem = new JRadioButtonMenuItem();
private JRadioButtonMenuItem windowsStyleMenuItem = new JRadioButtonMenuItem();

// 定义帮助菜单
private JMenuItem aboutMenuItem = new JMenuItem();
private JMenuItem helpTopicMenuItem = new JMenuItem();
private JMenu helpMenu = new JMenu();

// 构造函数
public Notepad(){
initComponents();
}

private void initComponents(){

// 添加子菜单项到文件菜单
fileMenu.setText("/u6587/u4ef6 (F)");
newMenuItem.setText(" 新建(N) Ctrl+N");
openMenuItem.setText(" 打开(O)... Ctrl+O");
saveMenuItem.setText(" 保存(S) Ctrl+S");
saveAsMenuItem.setText(" 另存为(A)...");
pageSetupMenuItem.setText(" 页面设置(U)...");
printMenuItem.setText(" 打印(P)... Ctrl+P");
exitMenuItem.setText(" 退出");
fileMenu.add(newMenuItem);
fileMenu.add(openMenuItem);
fileMenu.add(saveMenuItem);
fileMenu.add(saveAsMenuItem);
fileMenu.addSeparator();
fileMenu.add(pageSetupMenuItem);
fileMenu.add(printMenuItem);
fileMenu.addSeparator();
fileMenu.add(exitMenuItem);

// 添加子菜单项到风格菜单
styleMenu.setText("风格(S)");
javaStyleMenuItem.setText("Java默认");
metalStyleMenuItem.setText("Metal风格");
windowsStyleMenuItem.setText("Windows风格");
styleMenuGroup.add(javaStyleMenuItem);
styleMenuGroup.add(metalStyleMenuItem);
styleMenuGroup.add(windowsStyleMenuItem);
styleMenu.add(javaStyleMenuItem);
styleMenu.add(metalStyleMenuItem);
styleMenu.add(windowsStyleMenuItem);

// 添加子菜单项到帮助菜单
helpMenu.setText("帮助(H)");
helpTopicMenuItem.setText(" 帮助主题(H)");
aboutMenuItem.setText(" 关于记事本(A)");
helpMenu.add(helpTopicMenuItem);
helpMenu.addSeparator();
helpMenu.add(aboutMenuItem);

// 定义文件菜单下的事件监听
newMenuItem.addActionListener(new newMenuItem_actionAdapter(this));
openMenuItem.addActionListener(new openMenuItem_actionAdapter(this));
saveMenuItem.addActionListener(new saveMenuItem_actionAdapter(this));
saveAsMenuItem.addActionListener(new saveAsMenuItem_actionAdapter(this));
pageSetupMenuItem.addActionListener(new pageSetupMenuItem_actionAdapter(this));
printMenuItem.addActionListener(new printMenuItem_actionAdapter(this));
exitMenuItem.addActionListener(new exitMenuItem_actionAdapter(this));

// 定义风格菜单下的事件监听
javaStyleMenuItem.addActionListener(new javaStyleMenuItem_actionAdapter(this));
metalStyleMenuItem.addActionListener(new metalStyleMenuItem_actionAdapter(this));
windowsStyleMenuItem.addActionListener(new windowsStyleMenuItem_actionAdapter(this));

// 定义帮助菜单下的事件监听
helpTopicMenuItem.addActionListener(new helpTopicMenuItem_actionAdapter(this));
aboutMenuItem.addActionListener(new aboutMenuItem_actionAdapter(this));

// 填加菜单到菜单栏
menuBar.add(fileMenu);
menuBar.add(styleMenu);
menuBar.add(helpMenu);

// 对主窗口的一些设置
this.setDefaultCloseOperation(EXIT_ON_CLOSE);
this.setTitle("无标题 - /u8bb0/u4e8b/u672c");
this.setSize(640,480);

setJMenuBar(menuBar);
pane.setLayout(bord);
pane.add("Center",scroll);
setContentPane(pane);
}
// 定义新建菜单项方法
public void newMenuItemActionPerformed(ActionEvent evt){
file = null;
if(!("".equals(content.getText()))){
Object[] options = { " 是(Y) ", " 否(N) "," 取消 " };
int s = JOptionPane.showOptionDialog(null, "/u6587/u4ef6 "+getTitle()+" /u7684/u6587/u5b57/u5df2/u7ecf/u6539/u53d8/u3002/n/u60f3/u4fdd/u5b58/u6587/u4ef6/u5417/uff1f", "/u8bb0/u4e8b/u672c",
JOptionPane.DEFAULT_OPTION, JOptionPane.WARNING_MESSAGE,
null, options, options[0]);
switch(s){
case 0:
int returnVal=filechooser.showSaveDialog(this);
if(returnVal == JFileChooser.APPROVE_OPTION) {
file=filechooser.getSelectedFile();
try{
FileWriter fw=new FileWriter(file);
fw.write(content.getText());
setTitle(filechooser.getSelectedFile().getName()+" - /u8bb0/u4e8b/u672c");
fw.close();
}
catch(Exception e){
e.printStackTrace();
}
break;
}
case 1:
content.setText("");
setTitle("无标题 - /u8bb0/u4e8b/u672c");
}
}
}

// 定义打开菜单项方法
public void openMenuItemActionPerformed(ActionEvent evt){
try {
file = null;
int returnVal = filechooser.showOpenDialog(this);
if(returnVal == JFileChooser.APPROVE_OPTION){
file = filechooser.getSelectedFile();
FileReader fr = new FileReader(file);
int len = (int)file.length();
char[] buffer = new char[len];
fr.read(buffer,0,len);
fr.close();
content.setText(new String(buffer));
}
}
catch(Exception e){
e.printStackTrace();
}
}

// 定义退出菜单项方法
public void exitMenuItem_actionPerformed(ActionEvent e){
if(!("".equals(content.getText()))){
Object[] options = { " 是(Y) ", " 否(N) "," 取消 " };
int s = JOptionPane.showOptionDialog(null, "文件的文字已经改变。/n想保存文件吗？", "/u8bb0/u4e8b/u672c",
JOptionPane.DEFAULT_OPTION, JOptionPane.WARNING_MESSAGE,
null, options, options[0]);
switch(s){
case 0:
int returnVal=filechooser.showSaveDialog(this);
if(returnVal == JFileChooser.APPROVE_OPTION) {
file=filechooser.getSelectedFile();
try{
FileWriter fw=new FileWriter(file);
fw.write(content.getText());
setTitle(filechooser.getSelectedFile().getName()+" - /u8bb0/u4e8b/u672c");
fw.close();
}
catch(Exception ex){
ex.printStackTrace();
}
break;
}
case 1:
System.exit(0);
}
}
else{
System.exit(0);
}
}

// 保存事件
public void saveMenuItemActionPerformed(ActionEvent evt){
int returnVal=filechooser.showSaveDialog(this);
if(returnVal == JFileChooser.APPROVE_OPTION) {
file=filechooser.getSelectedFile();

try{
FileWriter fw=new FileWriter(file);
fw.write(content.getText());
setTitle(filechooser.getSelectedFile().getName()+" - /u8bb0/u4e8b/u672c");
fw.close();
}
catch(Exception e){
e.printStackTrace();
}
}
}

// 另存为事件
public void saveAsMenuItemActionPerformed(ActionEvent evt){
filechooser.setDialogTitle("另存为...");
int returnVal = filechooser.showSaveDialog(this);
if(returnVal == JFileChooser.APPROVE_OPTION) {
file=filechooser.getSelectedFile();
try{
FileWriter fw=new FileWriter(file);
fw.write(content.getText());
setTitle(filechooser.getSelectedFile().getName()+" - /u8bb0/u4e8b/u672c");
fw.close();
}
catch(Exception e){
e.printStackTrace();
}

}

}

// 页面设置事件
public void pageSetupMenuItemActionPerformed(ActionEvent evt){
JOptionPane.showMessageDialog(null,"此功能正在开发中...");
}

// 打印事件
public void printMenuItemActionPerformed(ActionEvent evt){
JOptionPane.showMessageDialog(null,"打印中...");
}

// 更新风格外观方法
void changeLookFeel(String className) {
try {
UIManager.setLookAndFeel(className);
}
catch (Exception e) {
System.out.println(e);
}
SwingUtilities.updateComponentTreeUI(this);
}

// Java风格事件
public void javaStyleMenuItemActionPerformed(ActionEvent evt){
changeLookFeel("javax.swing.plaf.metal.MetalLookAndFeel");
}

// Motif风格事件
public void metalStyleMenuItemActionPerformed(ActionEvent evt){
changeLookFeel("com.sun.java.swing.plaf.motif.MotifLookAndFeel");
}

// MAC风格事件
public void windowsStyleMenuItemActionPerformed(ActionEvent evt){
changeLookFeel("com.sun.java.swing.plaf.windows.WindowsLookAndFeel");
}
// 帮助事件
public void helpTopicMenuItemActionPerformed(ActionEvent evt){
JOptionPane.showMessageDialog(null,"/u9700/u8981/u5e2e/u52a9/u5417/uff1f");
}

// 关于事件
public void aboutMenuItemActionPerformed(ActionEvent evt){
JOptionPane.showMessageDialog(null,"/n/u7a0b/u5e8f/u540d/u79f0/uff1aJava /u8bb0/u4e8b/u672c/n/u4ee3/u7801/u7f16/u5199/uff1aCavien/n/u4f5c/u8005/u7f51/u7ad9/uff1ahttp:/www.cavien.com/nE-mail/u3000/uff1aCavien@163.com");

}
// 主函数
public static void main(String args[]) {
Notepad notepad = new Notepad();
notepad.setVisible(true);
}

}

// 定义新建事件类
class newMenuItem_actionAdapter implements ActionListener{
Notepad adaptee;

newMenuItem_actionAdapter(Notepad adaptee){
this.adaptee = adaptee;
}
public void actionPerformed(ActionEvent evt){
adaptee.newMenuItemActionPerformed(evt);
}
}
// 定义打开事件类
class openMenuItem_actionAdapter implements ActionListener{
Notepad adaptee;

openMenuItem_actionAdapter(Notepad adaptee){
this.adaptee = adaptee;
}
public void actionPerformed(ActionEvent evt){
adaptee.openMenuItemActionPerformed(evt);
}
}

// 定义保存事件类
class saveMenuItem_actionAdapter implements ActionListener{
Notepad adaptee;

saveMenuItem_actionAdapter(Notepad adaptee){
this.adaptee = adaptee;
}
public void actionPerformed(ActionEvent evt){
adaptee.saveMenuItemActionPerformed(evt);
}
}

// 定义另存为事件类
class saveAsMenuItem_actionAdapter implements ActionListener{
Notepad adaptee;

saveAsMenuItem_actionAdapter(Notepad adaptee){
this.adaptee = adaptee;
}
public void actionPerformed(ActionEvent evt){
adaptee.saveAsMenuItemActionPerformed(evt);
}
}

// 定义页面设置事件类
class pageSetupMenuItem_actionAdapter implements ActionListener{
Notepad adaptee;

pageSetupMenuItem_actionAdapter(Notepad adaptee){
this.adaptee = adaptee;
}
public void actionPerformed(ActionEvent evt){
adaptee.pageSetupMenuItemActionPerformed(evt);
}
}

// 定义打印事件类
class printMenuItem_actionAdapter implements ActionListener{
Notepad adaptee;

printMenuItem_actionAdapter(Notepad adaptee){
this.adaptee = adaptee;
}
public void actionPerformed(ActionEvent evt){
adaptee.printMenuItemActionPerformed(evt);
}
}

// 定义Java风格事件类
class javaStyleMenuItem_actionAdapter implements ActionListener{
Notepad adaptee;

javaStyleMenuItem_actionAdapter(Notepad adaptee){
this.adaptee = adaptee;
}
public void actionPerformed(ActionEvent evt){
adaptee.javaStyleMenuItemActionPerformed(evt);

}
}

// 定义Java风格事件类
class metalStyleMenuItem_actionAdapter implements ActionListener{
Notepad adaptee;

metalStyleMenuItem_actionAdapter(Notepad adaptee){
this.adaptee = adaptee;
}
public void actionPerformed(ActionEvent evt){
adaptee.metalStyleMenuItemActionPerformed(evt);
}
}

// 定义Java风格事件类
class windowsStyleMenuItem_actionAdapter implements ActionListener{
Notepad adaptee;

windowsStyleMenuItem_actionAdapter(Notepad adaptee){
this.adaptee = adaptee;
}
public void actionPerformed(ActionEvent evt){
adaptee.windowsStyleMenuItemActionPerformed(evt);
}
}

// 定义帮助主题事件类
class helpTopicMenuItem_actionAdapter implements ActionListener{
Notepad adaptee;

helpTopicMenuItem_actionAdapter(Notepad adaptee){
this.adaptee = adaptee;
}
public void actionPerformed(ActionEvent evt){
adaptee.helpTopicMenuItemActionPerformed(evt);
}
}

// 定义关于软件事件类
class aboutMenuItem_actionAdapter implements ActionListener{
Notepad adaptee;

aboutMenuItem_actionAdapter(Notepad adaptee){
this.adaptee = adaptee;
}
public void actionPerformed(ActionEvent evt){
adaptee.aboutMenuItemActionPerformed(evt);
}
}

// 定义退出事件类
class exitMenuItem_actionAdapter implements ActionListener {
Notepad adaptee;

exitMenuItem_actionAdapter(Notepad adaptee){
this.adaptee = adaptee;
}
public void actionPerformed(ActionEvent evt){
adaptee.exitMenuItem_actionPerformed(evt);
}