Java课程设计源码——Java记事本，

Java课程设计源码——Java记事本，

Java课程设计——Java记事本

借鉴了网上的一些代码，这是源码，可直接拿去运行。

package notepad;

import java.awt.*;
import java.awt.event.*; 
import java.util.*;
import java.io.*;
import javax.swing.undo.*;
import javax.swing.*;
import javax.swing.event.*;
import java.awt.datatransfer.*; 

public class Notepad extends JFrame implements ActionListener, DocumentListener{
	// 菜单
	JMenu fileMenu, editMenu, formatMenu, viewMenu, helpMenu;
	// 右键弹出菜单项
	JPopupMenu popupMenu;
	JMenuItem popupMenu_Undo, popupMenu_Cut, popupMenu_Copy, popupMenu_Paste, popupMenu_Delete, popupMenu_SelectAll;
	// “文件”的菜单项
	JMenuItem fileMenu_New, fileMenu_Open, fileMenu_Save, fileMenu_SaveAs, fileMenu_PageSetUp, fileMenu_Print,
			fileMenu_Exit;
	// “编辑”的菜单项
	JMenuItem editMenu_Undo, editMenu_Cut, editMenu_Copy, editMenu_Paste, editMenu_Delete, editMenu_Find,
			editMenu_FindNext, editMenu_Replace, editMenu_GoTo, editMenu_SelectAll, editMenu_TimeDate;
	// “格式”的菜单项
	JCheckBoxMenuItem formatMenu_LineWrap;
	JMenuItem formatMenu_Font;
	// “查看”的菜单项
	JCheckBoxMenuItem viewMenu_Status;
	// “帮助”的菜单项
	JMenuItem helpMenu_HelpTopics, helpMenu_AboutNotepad;
	// “文本”编辑区域
	JTextArea editArea;
	// 状态栏标签
	JLabel statusLabel;
	// 获取系统剪贴板
	Toolkit toolkit = Toolkit.getDefaultToolkit();
	Clipboard clipBoard = toolkit.getSystemClipboard();
	// 创建撤销操作管理器(与撤销操作有关)
	protected UndoManager undo = new UndoManager();
	
	// 其他变量
	String oldValue;// 存放编辑区原来的内容，用于比较文本是否有改动
	boolean isNewFile = true;// 是否新文件(未保存过的)
	File currentFile;// 当前文件名

	// 构造函数开始
	public Notepad() {
		super("Java记事本");
		// 设置菜单系统内组件的字体
		Font font = new Font("Dialog", Font.PLAIN, 12);
		Enumeration keys = UIManager.getDefaults().keys();
		while (keys.hasMoreElements()) {
			Object key = keys.nextElement();
			Object value = UIManager.get(key);
			if (value instanceof javax.swing.plaf.FontUIResource) {
				UIManager.put(key, font);
			}
		}

		// 创建菜单条
		JMenuBar menuBar = new JMenuBar();
		// 创建文件菜单及菜单项并注册事件监听
		fileMenu = new JMenu("文件(F)");
		fileMenu.setMnemonic('F');// 设置快捷键ALT+F

		fileMenu_New = new JMenuItem("新建(N)");
		fileMenu_New.setAccelerator(KeyStroke.getKeyStroke(KeyEvent.VK_N, InputEvent.CTRL_MASK));
		fileMenu_New.addActionListener(this);

		fileMenu_Open = new JMenuItem("打开(O)...");
		fileMenu_Open.setAccelerator(KeyStroke.getKeyStroke(KeyEvent.VK_O, InputEvent.CTRL_MASK));
		fileMenu_Open.addActionListener(this);

		fileMenu_Save = new JMenuItem("保存(S)");
		fileMenu_Save.setAccelerator(KeyStroke.getKeyStroke(KeyEvent.VK_S, InputEvent.CTRL_MASK));
		fileMenu_Save.addActionListener(this);

		fileMenu_SaveAs = new JMenuItem("另存为(A)...");
		fileMenu_SaveAs.addActionListener(this);

		fileMenu_Exit = new JMenuItem("退出(X)");
		fileMenu_Exit.addActionListener(this);

		// 向菜单条添加"文件"菜单及菜单项
		menuBar.add(fileMenu);
		fileMenu.add(fileMenu_New);
		fileMenu.add(fileMenu_Open);
		fileMenu.add(fileMenu_Save);
		fileMenu.add(fileMenu_SaveAs);
		fileMenu.addSeparator(); // 分隔线
		fileMenu.add(fileMenu_Exit);

		// 创建编辑菜单及菜单项并注册事件监听
		editMenu = new JMenu("编辑(E)");
		editMenu.setMnemonic('E');// 设置快捷键ALT+E
		// 当选择编辑菜单时，设置剪切、复制、粘贴、删除等功能的可用性
		editMenu.addMenuListener(new MenuListener() {
			public void menuCanceled(MenuEvent e){   // 取消菜单时调用
				checkMenuItemEnabled();// 设置剪切、复制、粘贴、删除等功能的可用性
			}

			public void menuDeselected(MenuEvent e){  // 取消选择某个菜单时调用
				checkMenuItemEnabled();// 设置剪切、复制、粘贴、删除等功能的可用性
			}

			public void menuSelected(MenuEvent e){  // 选择某个菜单时调用
				checkMenuItemEnabled();// 设置剪切、复制、粘贴、删除等功能的可用性
			}
		});

		editMenu_Undo = new JMenuItem("撤销(U)");
		editMenu_Undo.setAccelerator(KeyStroke.getKeyStroke(KeyEvent.VK_Z, InputEvent.CTRL_MASK));
		editMenu_Undo.addActionListener(this);
		editMenu_Undo.setEnabled(false);// 默认禁止这一项

		editMenu_Cut = new JMenuItem("剪切(T)");
		editMenu_Cut.setAccelerator(KeyStroke.getKeyStroke(KeyEvent.VK_X, InputEvent.CTRL_MASK));
		editMenu_Cut.addActionListener(this);

		editMenu_Copy = new JMenuItem("复制(C)");
		editMenu_Copy.setAccelerator(KeyStroke.getKeyStroke(KeyEvent.VK_C, InputEvent.CTRL_MASK));
		editMenu_Copy.addActionListener(this);

		editMenu_Paste = new JMenuItem("粘贴(P)");
		editMenu_Paste.setAccelerator(KeyStroke.getKeyStroke(KeyEvent.VK_V, InputEvent.CTRL_MASK));
		editMenu_Paste.addActionListener(this);

		editMenu_Delete = new JMenuItem("删除(D)");
		editMenu_Delete.setAccelerator(KeyStroke.getKeyStroke(KeyEvent.VK_DELETE, 0));
		editMenu_Delete.addActionListener(this);

		editMenu_Find = new JMenuItem("查找(F)...");
		editMenu_Find.setAccelerator(KeyStroke.getKeyStroke(KeyEvent.VK_F, InputEvent.CTRL_MASK));
		editMenu_Find.addActionListener(this);

		editMenu_FindNext = new JMenuItem("查找下一个(N)");
		editMenu_FindNext.setAccelerator(KeyStroke.getKeyStroke(KeyEvent.VK_F3, 0));
		editMenu_FindNext.addActionListener(this);

		editMenu_Replace = new JMenuItem("替换(R)...", 'R');
		editMenu_Replace.setAccelerator(KeyStroke.getKeyStroke(KeyEvent.VK_H, InputEvent.CTRL_MASK));
		editMenu_Replace.addActionListener(this);

		editMenu_SelectAll = new JMenuItem("全选", 'A');
		editMenu_SelectAll.setAccelerator(KeyStroke.getKeyStroke(KeyEvent.VK_A, InputEvent.CTRL_MASK));
		editMenu_SelectAll.addActionListener(this);

		// 向菜单条添加"编辑"菜单及菜单项
		menuBar.add(editMenu);
		editMenu.add(editMenu_Undo);
		editMenu.addSeparator(); // 分隔线
		editMenu.add(editMenu_Cut);
		editMenu.add(editMenu_Copy);
		editMenu.add(editMenu_Paste);
		editMenu.add(editMenu_Delete);
		editMenu.addSeparator(); // 分隔线
		editMenu.add(editMenu_Find);
		editMenu.add(editMenu_FindNext);
		editMenu.add(editMenu_Replace);
		editMenu.addSeparator(); // 分隔线
		editMenu.add(editMenu_SelectAll);

		// 创建格式菜单及菜单项并注册事件监听
		formatMenu = new JMenu("格式(O)");
		formatMenu.setMnemonic('O');// 设置快捷键ALT+O

		formatMenu_LineWrap = new JCheckBoxMenuItem("自动换行(W)");//复选框菜单项
		formatMenu_LineWrap.setMnemonic('W');// 设置快捷键ALT+W
		formatMenu_LineWrap.setState(true);//默认选中
		formatMenu_LineWrap.addActionListener(this);

		formatMenu_Font = new JMenuItem("字体(F)...");
		formatMenu_Font.addActionListener(this);

		// 向菜单条添加"格式"菜单及菜单项
		menuBar.add(formatMenu);
		formatMenu.add(formatMenu_LineWrap);
		formatMenu.add(formatMenu_Font);

		// 创建查看菜单及菜单项并注册事件监听
		viewMenu = new JMenu("查看(V)");
		viewMenu.setMnemonic('V');// 设置快捷键ALT+V

		viewMenu_Status = new JCheckBoxMenuItem("状态栏(S)");
		viewMenu_Status.setMnemonic('S');// 设置快捷键ALT+S
		viewMenu_Status.setState(true);
		viewMenu_Status.addActionListener(this);

		// 向菜单条添加"查看"菜单及菜单项
		menuBar.add(viewMenu);
		viewMenu.add(viewMenu_Status);

		// 创建帮助菜单及菜单项并注册事件监听
		helpMenu = new JMenu("帮助(H)");
		helpMenu.setMnemonic('H');// 设置快捷键ALT+H

		helpMenu_HelpTopics = new JMenuItem("帮助主题(H)");
		helpMenu_HelpTopics.setAccelerator(KeyStroke.getKeyStroke(KeyEvent.VK_F1, 0));
		helpMenu_HelpTopics.addActionListener(this);

		// 向菜单条添加"帮助"菜单及菜单项
		menuBar.add(helpMenu);
		helpMenu.add(helpMenu_HelpTopics);

		// 向窗口添加菜单条
		this.setJMenuBar(menuBar);

		// 创建文本编辑区并添加滚动条
		editArea = new JTextArea(30, 80);
		JScrollPane scroller = new JScrollPane(editArea);
		scroller.setVerticalScrollBarPolicy(JScrollPane.VERTICAL_SCROLLBAR_ALWAYS);
		this.add(scroller, BorderLayout.CENTER);// 向窗口添加文本编辑区
		editArea.setWrapStyleWord(true);// 设置单词在一行不足容纳时换行
		editArea.setLineWrap(true);// 设置文本编辑区自动换行默认为true,即会"自动换行"
		// this.add(editArea,BorderLayout.CENTER);
		oldValue = editArea.getText();// 获取原文本编辑区的内容

		// 编辑区注册事件监听(与撤销操作有关)
		editArea.getDocument().addUndoableEditListener(undo);//JTextField JPasswordField中的撤销事件监听
		editArea.getDocument().addDocumentListener(this);//文本区事件

		// 创建右键弹出菜单
		popupMenu = new JPopupMenu();
		popupMenu_Undo = new JMenuItem("撤销(U)");
		popupMenu_Cut = new JMenuItem("剪切(T)");
		popupMenu_Copy = new JMenuItem("复制(C)");
		popupMenu_Paste = new JMenuItem("粘帖(P)");
		popupMenu_Delete = new JMenuItem("删除(D)");
		popupMenu_SelectAll = new JMenuItem("全选(A)");

		// 向右键菜单添加菜单项和分隔符
		popupMenu.add(popupMenu_Undo);
		popupMenu.addSeparator();
		popupMenu.add(popupMenu_Cut);
		popupMenu.add(popupMenu_Copy);
		popupMenu.add(popupMenu_Paste);
		popupMenu.add(popupMenu_Delete);
		popupMenu.addSeparator();
		popupMenu.add(popupMenu_SelectAll);

		// 文本编辑区注册右键菜单事件
		popupMenu_Undo.addActionListener(this);
		popupMenu_Cut.addActionListener(this);
		popupMenu_Copy.addActionListener(this);
		popupMenu_Paste.addActionListener(this);
		popupMenu_Delete.addActionListener(this);
		popupMenu_SelectAll.addActionListener(this);

		// 文本编辑区注册右键菜单事件
		editArea.addMouseListener(new MouseAdapter() {
			public void mousePressed(MouseEvent e) {
				if (e.isPopupTrigger()){// 返回此鼠标事件是否为该平台的弹出菜单触发事件
					popupMenu.show(e.getComponent(), e.getX(), e.getY());// 在组件调用者的坐标空间中的位置 显示弹出菜单
				}
				checkMenuItemEnabled();// 设置剪切，复制，粘帖，删除等功能的可用性
				editArea.requestFocus();// 编辑区获取焦点
			}

			public void mouseReleased(MouseEvent e) {
				if (e.isPopupTrigger()){// 返回此鼠标事件是否为该平台的弹出菜单触发事件
					popupMenu.show(e.getComponent(), e.getX(), e.getY());// 在组件调用者的坐标空间中的位置 显示弹出菜单
				}
				checkMenuItemEnabled();// 设置剪切，复制，粘帖，删除等功能的可用性
				editArea.requestFocus();// 编辑区获取焦点
			}
		});// 文本编辑区注册右键菜单事件结束

		// 创建和添加状态栏
		statusLabel = new JLabel("按F1获取帮助");
		this.add(statusLabel, BorderLayout.SOUTH);// 向窗口添加状态栏标签

		// 设置窗口在屏幕上的位置、大小和可见性
		this.setLocation(100, 100);
		this.setSize(800, 600);
		this.setVisible(true);
		
		// 添加窗口监听器
		addWindowListener(new WindowAdapter() {
			public void windowClosing(WindowEvent e) {
				exitWindowChoose();
			}
		});

		checkMenuItemEnabled();
		editArea.requestFocus();
	}// 构造函数Notepad结束

	// 设置菜单项的可用性：剪切，复制，粘帖，删除功能
	public void checkMenuItemEnabled() {
		String selectText = editArea.getSelectedText();
		if (selectText == null) {
			editMenu_Cut.setEnabled(false);
			popupMenu_Cut.setEnabled(false);
			editMenu_Copy.setEnabled(false);
			popupMenu_Copy.setEnabled(false);
			editMenu_Delete.setEnabled(false);
			popupMenu_Delete.setEnabled(false);
		} else {
			editMenu_Cut.setEnabled(true);
			popupMenu_Cut.setEnabled(true);
			editMenu_Copy.setEnabled(true);
			popupMenu_Copy.setEnabled(true);
			editMenu_Delete.setEnabled(true);
			popupMenu_Delete.setEnabled(true);
		}
		// 粘帖功能可用性判断
		Transferable contents = clipBoard.getContents(this);  // 获取剪贴板中的内容
		if (contents == null) {
			editMenu_Paste.setEnabled(false);
			popupMenu_Paste.setEnabled(false);
		} else {
			editMenu_Paste.setEnabled(true);
			popupMenu_Paste.setEnabled(true);
		}
	}// 方法checkMenuItemEnabled()结束

	// 关闭窗口时调用
	public void exitWindowChoose() {
		editArea.requestFocus();
		String currentValue = editArea.getText();
		if (currentValue.equals(oldValue) == true) {
			System.exit(0);
		} else {
			int exitChoose = JOptionPane.showConfirmDialog(this, "您的文件尚未保存，是否保存？", "退出提示",
					JOptionPane.YES_NO_CANCEL_OPTION);
			if (exitChoose == JOptionPane.YES_OPTION) { // boolean isSave=false;
				if (isNewFile) {
					String str = null;
					JFileChooser fileChooser = new JFileChooser();// Java Swing提供的文件选择对话框
					fileChooser.setFileSelectionMode(JFileChooser.FILES_ONLY);// 指示仅显示文件
					fileChooser.setDialogTitle("文件另存为……");// 设置显示在 JFileChooser 窗口标题栏的字符串。

					int result = fileChooser.showSaveDialog(this);// 弹出一个 "Save File" 文件选择器对话框。

					if (result == JFileChooser.CANCEL_OPTION) {
						return;
					}

					File saveFileName = fileChooser.getSelectedFile();//这个文件可能存在,可能不存在。如果不存在，返回的是--你在对话框中输入的文件名。

					if (saveFileName == null || saveFileName.getName().equals("")) {
						JOptionPane.showMessageDialog(this, "不合法的文件名", "不合法的文件名", JOptionPane.ERROR_MESSAGE);
					} else {
						try {
							FileWriter fw = new FileWriter(saveFileName);// 写文本文件
							BufferedWriter bfw = new BufferedWriter(fw);// 嵌套
							bfw.write(editArea.getText(), 0, editArea.getText().length());
							bfw.flush();
							fw.close();

							isNewFile = false;
							currentFile = saveFileName;
							oldValue = editArea.getText();

							this.setTitle(saveFileName.getName() + "  - 记事本");
							statusLabel.setText("　当前打开文件:" + saveFileName.getAbsoluteFile());
							// isSave=true;
						} catch (IOException ioException) {
						}
					}
				} else {
					try {
						FileWriter fw = new FileWriter(currentFile);
						BufferedWriter bfw = new BufferedWriter(fw);
						bfw.write(editArea.getText(), 0, editArea.getText().length());
						bfw.flush();
						fw.close();
						// isSave=true;
					} catch (IOException ioException) {
					}
				}
				System.exit(0);
			} else if (exitChoose == JOptionPane.NO_OPTION) {
				System.exit(0);
			} else {
				return;
			}
		}
	}// 关闭窗口时调用方法结束

	// 查找方法
	public void find() {
		final JDialog findDialog = new JDialog(this, "查找", false);// false时允许其他窗口同时处于激活状态(即无模式)
		Container con = findDialog.getContentPane();// 返回此对话框的contentPane对象
		con.setLayout(new FlowLayout(FlowLayout.LEFT));
		JLabel findContentLabel = new JLabel("查找内容(N)：");
		final JTextField findText = new JTextField(15);
		JButton findNextButton = new JButton("查找下一个(F)：");
		final JCheckBox matchCheckBox = new JCheckBox("区分大小写(C)");
		ButtonGroup bGroup = new ButtonGroup();//多斥按钮组
		final JRadioButton upButton = new JRadioButton("向上(U)");
		final JRadioButton downButton = new JRadioButton("向下(D)");
		downButton.setSelected(true);//默认向后找
		bGroup.add(upButton);
		bGroup.add(downButton);//装入

		JButton cancel = new JButton("取消");
		// 取消按钮事件处理
		cancel.addActionListener(new ActionListener() {
			public void actionPerformed(ActionEvent e) {
				findDialog.dispose();//关闭
			}
		});
		// "查找下一个"按钮监听
		findNextButton.addActionListener(new ActionListener() {
			public void actionPerformed(ActionEvent e) { 
				int k = 0, m = 0;
				final String str1, str2, str3, str4, strA, strB;
				str1 = editArea.getText();//全文
				str2 = findText.getText();//要查找的文字
				str3 = str1.toUpperCase();//将字符串小写字符转换为大写
				str4 = str2.toUpperCase();
				if (matchCheckBox.isSelected())// "区分大小写(C)"的JCheckBox是否被选中
				{
					strA = str1;
					strB = str2;
				} else// 不区分大小写,此时把所选内容全部化成大写(或小写)，以便于查找
				{
					strA = str3;
					strB = str4;
				}
				if (upButton.isSelected()) { 
					if (editArea.getSelectedText() == null)
						k = strA.lastIndexOf(strB, editArea.getCaretPosition() - 1 );//从光标位置从右向左寻找最后一次出现的索引
						//k返回指定字符在此字符串中第一次出现的索引，如果此字符串中没有这样的字符，则返回 -1。
					else
						k = strA.lastIndexOf(strB, editArea.getCaretPosition() - findText.getText().length() - 1);
					if (k > -1) { 
						editArea.setCaretPosition(k);
						editArea.select(k, k + strB.length());
					} else {
						JOptionPane.showMessageDialog(null, "找不到您查找的内容！", "查找", JOptionPane.INFORMATION_MESSAGE);
					}
				} else if (downButton.isSelected()) {
					if (editArea.getSelectedText() == null)
						k = strA.indexOf(strB, editArea.getCaretPosition() + 1);//从左向右找第一次出现的位置
					else
						k = strA.indexOf(strB, editArea.getCaretPosition() - findText.getText().length() + 1);
					if (k > -1) {
						editArea.setCaretPosition(k);
						editArea.select(k, k + strB.length());
					} else {
						JOptionPane.showMessageDialog(null, "找不到您查找的内容！", "查找", JOptionPane.INFORMATION_MESSAGE);
					}
				}
			}
		});// "查找下一个"按钮监听结束
			// 创建"查找"对话框的界面
		JPanel panel1 = new JPanel();
		JPanel panel2 = new JPanel();
		JPanel panel3 = new JPanel();
		JPanel directionPanel = new JPanel();
		directionPanel.setBorder(BorderFactory.createTitledBorder("方向"));
		// 设置directionPanel组件的边框;
		// BorderFactory.createTitledBorder(String
		// title)创建一个新标题边框，使用默认边框（浮雕化）、默认文本位置（位于顶线上）、默认调整 (leading)
		// 以及由当前外观确定的默认字体和文本颜色，并指定了标题文本。
		directionPanel.add(upButton);
		directionPanel.add(downButton);
		panel1.setLayout(new GridLayout(2, 1));
		panel1.add(findNextButton);
		panel1.add(cancel);
		panel2.add(findContentLabel);
		panel2.add(findText);
		panel2.add(panel1);
		panel3.add(matchCheckBox);
		panel3.add(directionPanel);
		con.add(panel2);
		con.add(panel3);
		findDialog.setSize(410, 180);
		findDialog.setResizable(false);// 不可调整大小
		findDialog.setLocation(230, 280);
		findDialog.setVisible(true);
	}// 查找方法结束

	// 替换方法
	public void replace() {
		final JDialog replaceDialog = new JDialog(this, "替换", false);// false时允许其他窗口同时处于激活状态(即无模式)
		Container con = replaceDialog.getContentPane();// 返回此对话框的contentPane对象
		con.setLayout(new FlowLayout(FlowLayout.CENTER));
		JLabel findContentLabel = new JLabel("查找内容(N)：");
		final JTextField findText = new JTextField(15);
		JButton findNextButton = new JButton("查找下一个(F):");
		JLabel replaceLabel = new JLabel("替换为(P)：");
		final JTextField replaceText = new JTextField(15);
		JButton replaceButton = new JButton("替换(R)");
		JButton replaceAllButton = new JButton("全部替换(A)");
		JButton cancel = new JButton("取消");
		cancel.addActionListener(new ActionListener() {
			public void actionPerformed(ActionEvent e) {
				replaceDialog.dispose();
			}
		});
		final JCheckBox matchCheckBox = new JCheckBox("区分大小写(C)");
		ButtonGroup bGroup = new ButtonGroup();
		final JRadioButton upButton = new JRadioButton("向上(U)");
		final JRadioButton downButton = new JRadioButton("向下(D)");
		downButton.setSelected(true);
		bGroup.add(upButton);
		bGroup.add(downButton);

		// "查找下一个"按钮监听
		findNextButton.addActionListener(new ActionListener() {
			public void actionPerformed(ActionEvent e) {
				int k = 0, m = 0;
				final String str1, str2, str3, str4, strA, strB;
				str1 = editArea.getText();
				str2 = findText.getText();
				str3 = str1.toUpperCase();
				str4 = str2.toUpperCase();
				if (matchCheckBox.isSelected())// 区分大小写
				{
					strA = str1;
					strB = str2;
				} else// 不区分大小写,此时把所选内容全部化成大写(或小写)，以便于查找
				{
					strA = str3;
					strB = str4;
				}
				if (upButton.isSelected()) { 
					if (editArea.getSelectedText() == null)
						k = strA.lastIndexOf(strB, editArea.getCaretPosition() - 1);
					else
						k = strA.lastIndexOf(strB, editArea.getCaretPosition() - findText.getText().length() - 1);
					if (k > -1) { 
						editArea.setCaretPosition(k);
						editArea.select(k, k + strB.length());
					} else {
						JOptionPane.showMessageDialog(null, "找不到您查找的内容！", "查找", JOptionPane.INFORMATION_MESSAGE);
					}
				} else if (downButton.isSelected()) {
					if (editArea.getSelectedText() == null)
						k = strA.indexOf(strB, editArea.getCaretPosition() + 1);
					else
						k = strA.indexOf(strB, editArea.getCaretPosition() - findText.getText().length() + 1 );
					if (k > -1) {
						editArea.setCaretPosition(k);
						editArea.select(k, k + strB.length());
					} else {
						JOptionPane.showMessageDialog(null, "找不到您查找的内容！", "查找", JOptionPane.INFORMATION_MESSAGE);
					}
				}
			}
		});// "查找下一个"按钮监听结束

		// "替换"按钮监听
		replaceButton.addActionListener(new ActionListener() {
			public void actionPerformed(ActionEvent e) {
				if (replaceText.getText().length() == 0 && editArea.getSelectedText() != null)
					editArea.replaceSelection("");
				if (replaceText.getText().length() > 0 && editArea.getSelectedText() != null)
					editArea.replaceSelection(replaceText.getText());
			}
		});// "替换"按钮监听结束

		// "全部替换"按钮监听
		replaceAllButton.addActionListener(new ActionListener() {
			public void actionPerformed(ActionEvent e) {
				editArea.setCaretPosition(0); // 将光标放到编辑区开头
				int k = 0, m = 0, replaceCount = 0;
				if (findText.getText().length() == 0) {
					JOptionPane.showMessageDialog(replaceDialog, "请填写查找内容!", "提示", JOptionPane.WARNING_MESSAGE);
					findText.requestFocus(true);
					return;
				}
				while (k > -1)// 当文本中有内容被选中时(k>-1被选中)进行替换，否则不进行while循环
				{ // "区分大小写(C)"的JCheckBox是否被选中
					final String str1, str2, str3, str4, strA, strB;
					str1 = editArea.getText();
					str2 = findText.getText();
					str3 = str1.toUpperCase();
					str4 = str2.toUpperCase();
					if (matchCheckBox.isSelected())// 区分大小写
					{
						strA = str1;
						strB = str2;
					} else// 不区分大小写,此时把所选内容全部化成大写(或小写)，以便于查找
					{
						strA = str3;
						strB = str4;
					}
					if (upButton.isSelected()) {
						if (editArea.getSelectedText() == null)
							k = strA.lastIndexOf(strB, editArea.getCaretPosition()   );
						else
							k = strA.lastIndexOf(strB, editArea.getCaretPosition() - findText.getText().length()  );
						if (k > -1) { 
							editArea.setCaretPosition(k);
							editArea.select(k, k + strB.length());
						} else {
							if (replaceCount == 0) {
								JOptionPane.showMessageDialog(replaceDialog, "找不到您查找的内容!", "记事本",
										JOptionPane.INFORMATION_MESSAGE);
							} else {
								JOptionPane.showMessageDialog(replaceDialog, "成功替换" + replaceCount + "个匹配内容!", "替换成功",
										JOptionPane.INFORMATION_MESSAGE);
							}
						}
					} else if (downButton.isSelected()) {
						if (editArea.getSelectedText() == null)
							k = strA.indexOf(strB, editArea.getCaretPosition()  );
						else
							k = strA.indexOf(strB, editArea.getCaretPosition() - findText.getText().length() );
						if (k > -1) { 
							editArea.setCaretPosition(k);
							editArea.select(k, k + strB.length());
						} else {
							if (replaceCount == 0) {
								JOptionPane.showMessageDialog(replaceDialog, "找不到您查找的内容!", "记事本",
										JOptionPane.INFORMATION_MESSAGE);
							} else {
								JOptionPane.showMessageDialog(replaceDialog, "成功替换" + replaceCount + "个匹配内容!", "替换成功",
										JOptionPane.INFORMATION_MESSAGE);
							}
						}
					}
					if (replaceText.getText().length() == 0 && editArea.getSelectedText() != null) {
						editArea.replaceSelection("");
						replaceCount++;
					}

					if (replaceText.getText().length() > 0 && editArea.getSelectedText() != null) {
						editArea.replaceSelection(replaceText.getText());
						replaceCount++;
					}
				} // while循环结束
			}
		});// "替换全部"方法结束

		// 创建"替换"对话框的界面
		JPanel directionPanel = new JPanel();
		directionPanel.setBorder(BorderFactory.createTitledBorder("方向"));
		directionPanel.add(upButton);
		directionPanel.add(downButton);
		JPanel panel1 = new JPanel();
		JPanel panel2 = new JPanel();
		JPanel panel3 = new JPanel();
		JPanel panel4 = new JPanel();
		panel4.setLayout(new GridLayout(2, 1));
		panel1.add(findContentLabel);
		panel1.add(findText);
		panel1.add(findNextButton);
		panel4.add(replaceButton);
		panel4.add(replaceAllButton);
		panel2.add(replaceLabel);
		panel2.add(replaceText);
		panel2.add(panel4);
		panel3.add(matchCheckBox);
		panel3.add(directionPanel);
		panel3.add(cancel);
		con.add(panel1);
		con.add(panel2);
		con.add(panel3);
		replaceDialog.setSize(420, 220);
		replaceDialog.setResizable(true);// 
		replaceDialog.setLocation(230, 280);
		replaceDialog.setVisible(true);
	}// "全部替换"按钮监听结束

	// "字体"方法
	public void font() {
		final JDialog fontDialog = new JDialog(this, "字体设置", false);
		Container con = fontDialog.getContentPane();
		con.setLayout(new FlowLayout(FlowLayout.LEFT));
		JLabel fontLabel = new JLabel("字体(F)：");
		fontLabel.setPreferredSize(new Dimension(100, 20));// 构造一个Dimension，并将其初始化为指定宽度和高度
		JLabel styleLabel = new JLabel("字形(Y)：");
		styleLabel.setPreferredSize(new Dimension(100, 20));
		JLabel sizeLabel = new JLabel("大小(S)：");
		sizeLabel.setPreferredSize(new Dimension(100, 20));
		final JLabel sample = new JLabel("记事本");
		// sample.setHorizontalAlignment(SwingConstants.CENTER);
		final JTextField fontText = new JTextField(9);
		fontText.setPreferredSize(new Dimension(200, 20));
		final JTextField styleText = new JTextField(8);
		styleText.setPreferredSize(new Dimension(200, 20));
		final int style[] = { Font.PLAIN, Font.BOLD, Font.ITALIC, Font.BOLD + Font.ITALIC };
		final JTextField sizeText = new JTextField(5);
		sizeText.setPreferredSize(new Dimension(200, 20));
		JButton okButton = new JButton("确定");
		JButton cancel = new JButton("取消");
		cancel.addActionListener(new ActionListener() {
			public void actionPerformed(ActionEvent e) {
				fontDialog.dispose();
			}
		});
		Font currentFont = editArea.getFont();
		fontText.setText(currentFont.getFontName());
		fontText.selectAll();
		// styleText.setText(currentFont.getStyle());
		// styleText.selectAll();
		if (currentFont.getStyle() == Font.PLAIN)
			styleText.setText("常规");
		else if (currentFont.getStyle() == Font.BOLD)
			styleText.setText("粗体");
		else if (currentFont.getStyle() == Font.ITALIC)
			styleText.setText("斜体");
		else if (currentFont.getStyle() == (Font.BOLD + Font.ITALIC))
			styleText.setText("粗斜体");
		styleText.selectAll();
		String str = String.valueOf(currentFont.getSize());
		sizeText.setText(str);
		sizeText.selectAll();
		final JList fontList, styleList, sizeList;
		GraphicsEnvironment ge = GraphicsEnvironment.getLocalGraphicsEnvironment();
		final String fontName[] = ge.getAvailableFontFamilyNames();
		fontList = new JList(fontName);
		fontList.setFixedCellWidth(86);
		fontList.setFixedCellHeight(20);
		fontList.setSelectionMode(ListSelectionModel.SINGLE_SELECTION);
		final String fontStyle[] = { "常规", "粗体", "斜体", "粗斜体" };
		styleList = new JList(fontStyle);
		styleList.setFixedCellWidth(86);
		styleList.setFixedCellHeight(20);
		styleList.setSelectionMode(ListSelectionModel.SINGLE_SELECTION);
		if (currentFont.getStyle() == Font.PLAIN)
			styleList.setSelectedIndex(0);
		else if (currentFont.getStyle() == Font.BOLD)
			styleList.setSelectedIndex(1);
		else if (currentFont.getStyle() == Font.ITALIC)
			styleList.setSelectedIndex(2);
		else if (currentFont.getStyle() == (Font.BOLD + Font.ITALIC))
			styleList.setSelectedIndex(3);
		final String fontSize[] = { "8", "9", "10", "11", "12", "14", "16", "18", "20", "22", "24", "26", "28", "36",
				"48", "72" };
		sizeList = new JList(fontSize);
		sizeList.setFixedCellWidth(43);
		sizeList.setFixedCellHeight(20);
		sizeList.setSelectionMode(ListSelectionModel.SINGLE_SELECTION);
		fontList.addListSelectionListener(new ListSelectionListener() {
			public void valueChanged(ListSelectionEvent event) {
				fontText.setText(fontName[fontList.getSelectedIndex()]);
				fontText.selectAll();
				Font sampleFont1 = new Font(fontText.getText(), style[styleList.getSelectedIndex()],
						Integer.parseInt(sizeText.getText()));
				sample.setFont(sampleFont1);
			}
		});
		styleList.addListSelectionListener(new ListSelectionListener() {
			public void valueChanged(ListSelectionEvent event) {
				int s = style[styleList.getSelectedIndex()];
				styleText.setText(fontStyle[s]);
				styleText.selectAll();
				Font sampleFont2 = new Font(fontText.getText(), style[styleList.getSelectedIndex()],
						Integer.parseInt(sizeText.getText()));
				sample.setFont(sampleFont2);
			}
		});
		sizeList.addListSelectionListener(new ListSelectionListener() {
			public void valueChanged(ListSelectionEvent event) {
				sizeText.setText(fontSize[sizeList.getSelectedIndex()]);
				// sizeText.requestFocus();
				sizeText.selectAll();
				Font sampleFont3 = new Font(fontText.getText(), style[styleList.getSelectedIndex()],
						Integer.parseInt(sizeText.getText()));
				sample.setFont(sampleFont3);
			}
		});
		okButton.addActionListener(new ActionListener() {
			public void actionPerformed(ActionEvent e) {
				Font okFont = new Font(fontText.getText(), style[styleList.getSelectedIndex()],
						Integer.parseInt(sizeText.getText()));
				editArea.setFont(okFont);
				fontDialog.dispose();
			}
		});
		JPanel samplePanel = new JPanel();
		samplePanel.setBorder(BorderFactory.createTitledBorder("示例"));
		// samplePanel.setLayout(new FlowLayout(FlowLayout.CENTER));
		samplePanel.add(sample);
		JPanel panel1 = new JPanel();
		JPanel panel2 = new JPanel();
		JPanel panel3 = new JPanel();
		panel2.add(fontText);
		panel2.add(styleText);
		panel2.add(sizeText);
		panel2.add(okButton);
		panel3.add(new JScrollPane(fontList));// JList不支持直接滚动，所以要让JList作为JScrollPane的视口视图
		panel3.add(new JScrollPane(styleList));
		panel3.add(new JScrollPane(sizeList));
		panel3.add(cancel);
		con.add(panel1);
		con.add(panel2);
		con.add(panel3);
		con.add(samplePanel);
		fontDialog.setSize(350, 340);
		fontDialog.setLocation(200, 200);
		fontDialog.setResizable(false);
		fontDialog.setVisible(true);
	}
	// 新建
	public void actionPerformed(ActionEvent e) { 
		if (e.getSource() == fileMenu_New) {
			editArea.requestFocus();
			String currentValue = editArea.getText();
			boolean isTextChange = (currentValue.equals(oldValue)) ? false : true;
			if (isTextChange) {
				int saveChoose = JOptionPane.showConfirmDialog(this, "您的文件尚未保存，是否保存？", "提示",
						JOptionPane.YES_NO_CANCEL_OPTION);
				if (saveChoose == JOptionPane.YES_OPTION) {
					String str = null;
					JFileChooser fileChooser = new JFileChooser();
					fileChooser.setFileSelectionMode(JFileChooser.FILES_ONLY);
					fileChooser.setDialogTitle("另存为");
					int result = fileChooser.showSaveDialog(this);
					if (result == JFileChooser.CANCEL_OPTION) {
						//statusLabel.setText("您没有选择任何文件");
						return;
					}
					File saveFileName = fileChooser.getSelectedFile();
					if (saveFileName == null || saveFileName.getName().equals("")) {
						JOptionPane.showMessageDialog(this, "不合法的文件名", "不合法的文件名", JOptionPane.ERROR_MESSAGE);
					} else {
						try {
							FileWriter fw = new FileWriter(saveFileName);
							BufferedWriter bfw = new BufferedWriter(fw);
							bfw.write(editArea.getText(), 0, editArea.getText().length());
							bfw.flush();// 刷新该流的缓冲
							bfw.close();
							isNewFile = false;
							currentFile = saveFileName;
							oldValue = editArea.getText();
							this.setTitle(saveFileName.getName() + " - 记事本");
							statusLabel.setText("当前打开文件：" + saveFileName.getAbsoluteFile());
						} catch (IOException ioException) {
						}
					}
				} else if (saveChoose == JOptionPane.NO_OPTION) {
					editArea.replaceRange("", 0, editArea.getText().length());
					statusLabel.setText(" 新建文件");
					this.setTitle("无标题 - 记事本");
					isNewFile = true;
					undo.discardAllEdits(); // 撤消所有的"撤消"操作
					editMenu_Undo.setEnabled(false);
					oldValue = editArea.getText();
				} else if (saveChoose == JOptionPane.CANCEL_OPTION) {
					return;
				}
			} else {
				editArea.replaceRange("", 0, editArea.getText().length());
				statusLabel.setText(" 新建文件");
				this.setTitle("无标题 - 记事本");
				isNewFile = true;
				undo.discardAllEdits();// 撤消所有的"撤消"操作
				editMenu_Undo.setEnabled(false);
				oldValue = editArea.getText();
			}
		} // 新建结束
			// 打开
		else if (e.getSource() == fileMenu_Open) {
			editArea.requestFocus();
			String currentValue = editArea.getText();
			boolean isTextChange = (currentValue.equals(oldValue)) ? false : true;
			if (isTextChange) {
				int saveChoose = JOptionPane.showConfirmDialog(this, "您的文件尚未保存，是否保存？", "提示",
						JOptionPane.YES_NO_CANCEL_OPTION);
				if (saveChoose == JOptionPane.YES_OPTION) {
					String str = null;
					JFileChooser fileChooser = new JFileChooser();
					fileChooser.setFileSelectionMode(JFileChooser.FILES_ONLY);
					fileChooser.setDialogTitle("另存为");
					int result = fileChooser.showSaveDialog(this);
					if (result == JFileChooser.CANCEL_OPTION) {
						statusLabel.setText("您没有选择任何文件");
						return;
					}
					File saveFileName = fileChooser.getSelectedFile();
					if (saveFileName == null || saveFileName.getName().equals("")) {
						JOptionPane.showMessageDialog(this, "不合法的文件名", "不合法的文件名", JOptionPane.ERROR_MESSAGE);
					} else {
						try {
							FileWriter fw = new FileWriter(saveFileName);
							BufferedWriter bfw = new BufferedWriter(fw);
							bfw.write(editArea.getText(), 0, editArea.getText().length());
							bfw.flush();// 刷新该流的缓冲
							bfw.close();
							isNewFile = false;
							currentFile = saveFileName;
							oldValue = editArea.getText();
							this.setTitle(saveFileName.getName() + " - 记事本");
							statusLabel.setText("当前打开文件：" + saveFileName.getAbsoluteFile());
						} catch (IOException ioException) {
						}
					}
				} else if (saveChoose == JOptionPane.NO_OPTION) {
					String str = null;
					JFileChooser fileChooser = new JFileChooser();
					fileChooser.setFileSelectionMode(JFileChooser.FILES_ONLY);
					fileChooser.setDialogTitle("打开文件");
					int result = fileChooser.showOpenDialog(this);
					if (result == JFileChooser.CANCEL_OPTION) {
						statusLabel.setText("您没有选择任何文件");
						return;
					}
					File fileName = fileChooser.getSelectedFile();
					if (fileName == null || fileName.getName().equals("")) {
						JOptionPane.showMessageDialog(this, "不合法的文件名", "不合法的文件名", JOptionPane.ERROR_MESSAGE);
					} else {
						try {
							FileReader fr = new FileReader(fileName);
							BufferedReader bfr = new BufferedReader(fr);
							editArea.setText("");
							while ((str = bfr.readLine()) != null) {
								editArea.append(str);
							}
							this.setTitle(fileName.getName() + " - 记事本");
							statusLabel.setText(" 当前打开文件：" + fileName.getAbsoluteFile());
							fr.close();
							isNewFile = false;
							currentFile = fileName;
							oldValue = editArea.getText();
						} catch (IOException ioException) {
						}
					}
				} else {
					return;
				}
			} else {
				String str = null;
				JFileChooser fileChooser = new JFileChooser();
				fileChooser.setFileSelectionMode(JFileChooser.FILES_ONLY);
				fileChooser.setDialogTitle("打开文件");
				int result = fileChooser.showOpenDialog(this);
				if (result == JFileChooser.CANCEL_OPTION) {
					statusLabel.setText(" 您没有选择任何文件 ");
					return;
				}
				File fileName = fileChooser.getSelectedFile();
				if (fileName == null || fileName.getName().equals("")) {
					JOptionPane.showMessageDialog(this, "不合法的文件名", "不合法的文件名", JOptionPane.ERROR_MESSAGE);
				} else {
					try {
						FileReader fr = new FileReader(fileName);
						BufferedReader bfr = new BufferedReader(fr);
						editArea.setText("");
						while ((str = bfr.readLine()) != null) {
							editArea.append(str);
						}
						this.setTitle(fileName.getName() + " - 记事本");
						statusLabel.setText(" 当前打开文件：" + fileName.getAbsoluteFile());
						fr.close();
						isNewFile = false;
						currentFile = fileName;
						oldValue = editArea.getText();
					} catch (IOException ioException) {
					}
				}
			}
		} // 打开结束
			// 保存
		else if (e.getSource() == fileMenu_Save) {
			editArea.requestFocus();
			if (isNewFile) {
				String str = null;
				JFileChooser fileChooser = new JFileChooser();
				fileChooser.setFileSelectionMode(JFileChooser.FILES_ONLY);
				fileChooser.setDialogTitle("保存");
				int result = fileChooser.showSaveDialog(this);
				if (result == JFileChooser.CANCEL_OPTION) {
					statusLabel.setText("您没有选择任何文件");
					return;
				}
				File saveFileName = fileChooser.getSelectedFile();
				if (saveFileName == null || saveFileName.getName().equals("")) {
					JOptionPane.showMessageDialog(this, "不合法的文件名", "不合法的文件名", JOptionPane.ERROR_MESSAGE);
				} else {
					try {
						FileWriter fw = new FileWriter(saveFileName);
						BufferedWriter bfw = new BufferedWriter(fw);
						bfw.write(editArea.getText(), 0, editArea.getText().length());
						bfw.flush();// 刷新该流的缓冲
						bfw.close();
						isNewFile = false;
						currentFile = saveFileName;
						oldValue = editArea.getText();
						this.setTitle(saveFileName.getName() + " - 记事本");
						statusLabel.setText("当前打开文件：" + saveFileName.getAbsoluteFile());
					} catch (IOException ioException) {
					}
				}
			} else {
				try {
					FileWriter fw = new FileWriter(currentFile);
					BufferedWriter bfw = new BufferedWriter(fw);
					bfw.write(editArea.getText(), 0, editArea.getText().length());
					bfw.flush();
					fw.close();
				} catch (IOException ioException) {
				}
			}
		} // 保存结束
			// 另存为
		else if (e.getSource() == fileMenu_SaveAs) {
			editArea.requestFocus();
			String str = null;
			JFileChooser fileChooser = new JFileChooser();
			fileChooser.setFileSelectionMode(JFileChooser.FILES_ONLY);
			fileChooser.setDialogTitle("另存为");
			int result = fileChooser.showSaveDialog(this);
			if (result == JFileChooser.CANCEL_OPTION) {
				statusLabel.setText("您没有选择任何文件");
				return;
			}
			File saveFileName = fileChooser.getSelectedFile();
			if (saveFileName == null || saveFileName.getName().equals("")) {
				JOptionPane.showMessageDialog(this, "不合法的文件名", "不合法的文件名", JOptionPane.ERROR_MESSAGE);
			} else {
				try {
					FileWriter fw = new FileWriter(saveFileName);
					BufferedWriter bfw = new BufferedWriter(fw);
					bfw.write(editArea.getText(), 0, editArea.getText().length());
					bfw.flush();
					fw.close();
					oldValue = editArea.getText();
					this.setTitle(saveFileName.getName() + "  - 记事本");
					statusLabel.setText("　当前打开文件:" + saveFileName.getAbsoluteFile());
				} catch (IOException ioException) {
				}
			}
		} // 另存为结束
			
		// 退出
		else if (e.getSource() == fileMenu_Exit) {
			int exitChoose = JOptionPane.showConfirmDialog(this, "确定要退出吗?", "退出提示", JOptionPane.OK_CANCEL_OPTION);
			if (exitChoose == JOptionPane.OK_OPTION) {
				System.exit(0);
			} else {
				return;
			}
		} // 退出结束

		// 撤销
		else if (e.getSource() == editMenu_Undo || e.getSource() == popupMenu_Undo) {
			//editArea.requestFocus();
			if (undo.canUndo()) {
				try {
					undo.undo();
				} catch (CannotUndoException ex) {
					System.out.println("Unable to undo:" + ex);
					// ex.printStackTrace();
				}
			}
			if (!undo.canUndo()) {
				editMenu_Undo.setEnabled(false);
			}
		} // 撤销结束

		// 剪切
		else if (e.getSource() == editMenu_Cut || e.getSource() == popupMenu_Cut) {
			editArea.requestFocus();
			String text = editArea.getSelectedText();
			StringSelection selection = new StringSelection(text);
			clipBoard.setContents(selection, null);
			editArea.replaceRange("", editArea.getSelectionStart(), editArea.getSelectionEnd());
			checkMenuItemEnabled();// 设置剪切，复制，粘帖，删除功能的可用性
		} // 剪切结束

		// 复制
		else if (e.getSource() == editMenu_Copy || e.getSource() == popupMenu_Copy) {
			editArea.requestFocus();
			String text = editArea.getSelectedText();
			StringSelection selection = new StringSelection(text);
			clipBoard.setContents(selection, null);
			checkMenuItemEnabled();// 设置剪切，复制，粘帖，删除功能的可用性
		} // 复制结束

		// 粘帖
		else if (e.getSource() == editMenu_Paste || e.getSource() == popupMenu_Paste) {
			editArea.requestFocus();
			Transferable contents = clipBoard.getContents(this);
			if (contents == null)
				return;
			String text = "";
			try {
				text = (String) contents.getTransferData(DataFlavor.stringFlavor);
			} catch (Exception exception) {
			}
			editArea.replaceRange(text, editArea.getSelectionStart(), editArea.getSelectionEnd());
			checkMenuItemEnabled();
		} // 粘帖结束

		// 删除
		else if (e.getSource() == editMenu_Delete || e.getSource() == popupMenu_Delete) {
			editArea.requestFocus();
			editArea.replaceRange("", editArea.getSelectionStart(), editArea.getSelectionEnd());
			checkMenuItemEnabled(); // 设置剪切、复制、粘贴、删除等功能的可用性
		} // 删除结束

		// 查找
		else if (e.getSource() == editMenu_Find) {
			editArea.requestFocus();
			find();
		} // 查找结束

		// 查找下一个
		else if (e.getSource() == editMenu_FindNext) {
			editArea.requestFocus();
			find();
		} // 查找下一个结束

		// 替换
		else if (e.getSource() == editMenu_Replace) {
			editArea.requestFocus();
			replace();
		} // 替换结束

		// 全选
		else if (e.getSource() == editMenu_SelectAll || e.getSource() == popupMenu_SelectAll) {
			editArea.selectAll();
		} // 全选结束

		// 自动换行(已在前面设置)
		else if (e.getSource() == formatMenu_LineWrap) {
			if (formatMenu_LineWrap.getState())
				editArea.setLineWrap(true);
			else
				editArea.setLineWrap(false);
		} // 自动换行结束

		// 字体设置
		else if (e.getSource() == formatMenu_Font) {
			editArea.requestFocus();
			font();
		} // 字体设置结束

		// 设置状态栏可见性
		else if (e.getSource() == viewMenu_Status) {
			if (viewMenu_Status.getState())
				statusLabel.setVisible(true);
			else
				statusLabel.setVisible(false);
		} // 设置状态栏可见性结束

		// 帮助主题
		else if (e.getSource() == helpMenu_HelpTopics) {
			editArea.requestFocus();
			JOptionPane.showMessageDialog(this, "Java记事本", "帮助主题", JOptionPane.INFORMATION_MESSAGE);
		} // 帮助主题结束

	}// 方法actionPerformed()结束

	// 实现DocumentListener接口中的方法(与撤销操作有关)
	public void removeUpdate(DocumentEvent e) {
		editMenu_Undo.setEnabled(true);
	}

	public void insertUpdate(DocumentEvent e) {
		editMenu_Undo.setEnabled(true);
	}
	
	public void changedUpdate(DocumentEvent e) {
		editMenu_Undo.setEnabled(true);
	}// DocumentListener结束

	// main函数开始
	public static void main(String args[]) {
		Notepad notepad = new Notepad();
		notepad.setDefaultCloseOperation(JFrame.EXIT_ON_CLOSE);// 使用 System exit方法退出应用程序
	}// main函数结束

}