JAVA编写记事本

1、import java.awt.BorderLayout; import java.awt.Container; import java.awt.Font; import java.awt.event.ActionEvent; import java.awt.event.ActionListener; import java.awt.event.InputEvent; import java.awt.event.KeyAdapter; import java.awt.event.KeyEvent; import java.awt.event.MouseAdapter; import java.

2、awt.event.MouseEvent; import java.awt.event.WindowAdapter; import java.awt.event.WindowEvent; import java.io.BufferedReader; import java.io.BufferedWriter; import java.io.File; import java.io.FileReader; import java.io.FileWriter; import java.io.IOException; import javax.swing.BorderFactory; import

3、javax.swing.JFileChooser; import javax.swing.JFrame; import javax.swing.JLabel; import javax.swing.JMenu; import javax.swing.JMenuBar; import javax.swing.JMenuItem; import javax.swing.JOptionPane; import javax.swing.JPopupMenu; import javax.swing.JScrollPane; import javax.swing.JTextArea; import jav

4、ax.swing.KeyStroke; import javax.swing.ScrollPaneConstants; import javax.swing.SwingConstants; public class JNotePadUI extends JFrame private JMenuItem menuOpen; private JMenuItem menuSave; private JMenuItem menuSaveAs; private JMenuItem menuClose; private JMenu editMenu; private JMenuItem menuCut;

5、private JMenuItem menuCopy; private JMenuItem menuPaste; private JMenuItem menuAbout; private JTextArea textArea; private JLabel stateBar; private JFileChooser fileChooser; private JPopupMenu popUpMenu; public JNotePadUI( super(新建文本文件; setUpUIComponent(; setUpEventListener(; setVisible(true; private

6、 void setUpUIComponent( setSize(640, 480; / 菜单栏 JMenuBar menuBar = new JMenuBar(; / 设置文件菜单 JMenu fileMenu = new JMenu(文件; menuOpen = new JMenuItem(打开; / 快捷键设置 menuOpen.setAccelerator( KeyStroke.getKeyStroke( KeyEvent.VK_O, InputEvent.CTRL_MASK; menuSave = new JMenuItem(保存; menuSave.setAccelerator( K

7、eyStroke.getKeyStroke( KeyEvent.VK_S, InputEvent.CTRL_MASK; menuSaveAs = new JMenuItem(另存为; menuClose = new JMenuItem(关闭; menuClose.setAccelerator( KeyStroke.getKeyStroke( KeyEvent.VK_Q, InputEvent.CTRL_MASK; fileMenu.add(menuOpen; fileMenu.addSeparator(; / 分隔线 fileMenu.add(menuSave; fileMenu.add(me

8、nuSaveAs; fileMenu.addSeparator(; / 分隔线 fileMenu.add(menuClose; / 设置编辑菜单 JMenu editMenu = new JMenu(编辑; menuCut = new JMenuItem(剪切; menuCut.setAccelerator( KeyStroke.getKeyStroke(KeyEvent.VK_X, InputEvent.CTRL_MASK; menuCopy = new JMenuItem(复制; menuCopy.setAccelerator( KeyStroke.getKeyStroke(KeyEven

9、t.VK_C, InputEvent.CTRL_MASK; menuPaste = new JMenuItem(粘贴; menuPaste.setAccelerator( KeyStroke.getKeyStroke(KeyEvent.VK_V, InputEvent.CTRL_MASK; editMenu.add(menuCut; editMenu.add(menuCopy; editMenu.add(menuPaste; / 设置关于菜单 JMenu aboutMenu = new JMenu(关于; menuAbout = new JMenuItem(关于JNotePad; aboutM

10、enu.add(menuAbout; menuBar.add(fileMenu; menuBar.add(editMenu; menuBar.add(aboutMenu; setJMenuBar(menuBar; / 文字编辑区域 textArea = new JTextArea(; textArea.setFont(new Font(宋体, Font.PLAIN, 16; textArea.setLineWrap(true; JScrollPane panel = new JScrollPane(textArea, ScrollPaneConstants.VERTICAL_SCROLLBAR

11、_AS_NEEDED, ScrollPaneConstants.HORIZONTAL_SCROLLBAR_NEVER; Container contentPane = getContentPane(; contentPane.add(panel, BorderLayout.CENTER; / 状态栏 stateBar = new JLabel(未修改; stateBar.setHorizontalAlignment(SwingConstants.LEFT; stateBar.setBorder( BorderFactory.createEtchedBorder(; contentPane.ad

12、d(stateBar, BorderLayout.SOUTH; popUpMenu = editMenu.getPopupMenu(; fileChooser = new JFileChooser(; private void setUpEventListener( / 按下窗口关闭钮事件处理 addWindowListener( new WindowAdapter( public void windowClosing(WindowEvent e closeFile(; ; / 菜单 - 打开 menuOpen.addActionListener( new ActionListener( pu

13、blic void actionPerformed(ActionEvent e openFile(; ; / 菜单 - 保存 menuSave.addActionListener( new ActionListener( public void actionPerformed(ActionEvent e saveFile(; ; / 菜单 - 另存为 menuSaveAs.addActionListener( new ActionListener( public void actionPerformed(ActionEvent e saveFileAs(; ; / 菜单 - 关闭文件 menu

14、Close.addActionListener( new ActionListener( public void actionPerformed(ActionEvent e closeFile(; ; / 菜单 - 剪切 menuCut.addActionListener( new ActionListener( public void actionPerformed(ActionEvent e cut(; ; / 菜单 - 复制 menuCopy.addActionListener( new ActionListener( public void actionPerformed(Action

15、Event e copy(; ; / 菜单 - 粘贴 menuPaste.addActionListener( new ActionListener( public void actionPerformed(ActionEvent e paste(; ; / 菜单 - 关于 menuAbout.addActionListener( new ActionListener( public void actionPerformed(ActionEvent e / 显示对话框 JOptionPane.showOptionDialog(null, 程序名称:n JNotePad n + 程序设计:n n

16、 + 简介:n 一个简单的文字编辑器n + 可作为验收Java的实现对象n + 欢迎网友下载研究交流nn + /, 关于JNotePad, JOptionPane.DEFAULT_OPTION, JOptionPane.INFORMATION_MESSAGE, null, null, null; ; / 编辑区键盘事件 textArea.addKeyListener( new KeyAdapter( public void keyTyped(KeyEvent e processTextArea(; ; / 编辑区鼠标事件 textArea.addMouseListener( new Mouse

17、Adapter( public void mouseReleased(MouseEvent e if(e.getButton( = MouseEvent.BUTTON3 popUpMenu.show(editMenu, e.getX(, e.getY(; public void mouseClicked(MouseEvent e if(e.getButton( = MouseEvent.BUTTON1 popUpMenu.setVisible(false; ; private void openFile( if(isCurrentFileSaved( / 文件是否为保存状态 open(; /

18、打开 else / 显示对话框 int option = JOptionPane.showConfirmDialog( null, 文件已修改，是否保存？, 保存文件？, JOptionPane.YES_NO_OPTION, JOptionPane.WARNI NG_MESSAGE, null; switch(option / 确认文件保存 case JOptionPane.YES_OPTION: saveFile(; / 保存文件 break; / 放弃文件保存 case JOptionPane.NO_OPTION: open(; break; private boolean isCurre

19、ntFileSaved( if(stateBar.getText(.equals(未修改 return false; else return true; private void open( / fileChooser 是 JFileChooser 的实例 / 显示文件选取的对话框 int option = fileChooser.showDialog(null, null; / 使用者按下确认键 if(option = JFileChooser.APPROVE_OPTION try / 开启选取的文件 BufferedReader buf = new BufferedReader( new

20、FileReader( fileChooser.getSelectedFile(; / 设定文件标题 setTitle(fileChooser.getSelectedFile(.toString(; / 清除前一次文件 textArea.setText(; / 设定状态栏 stateBar.setText(未修改; / 取得系统相依的换行字符 String lineSeparator = System.getProperty(line.separator; / 读取文件并附加至文字编辑区 String text; while(text = buf.readLine( != null textA

21、rea.append(text; textArea.append(lineSeparator; buf.close(; catch(IOException e JOptionPane.showMessageDialog(null, e.toString(, 开启文件失败, JOptionPane.ERROR_MESSAGE; private void saveFile( / 从标题栏取得文件名称 File file = new File(getTitle(; / 若指定的文件不存在 if(!file.exists( / 执行另存为 saveFileAs(; else try / 开启指定的文件

22、 BufferedWriter buf = new BufferedWriter( new FileWriter(file; / 将文字编辑区的文字写入文件 buf.write(textArea.getText(; buf.close(; / 设定状态栏为未修改 stateBar.setText(未修改; catch(IOException e JOptionPane.showMessageDialog(null, e.toString(, 写入文件失败, JOptionPane.ERROR_MESSAGE; private void saveFileAs( / 显示文件对话框 int option = fileChooser.showSaveDialog(null; / 如果确认选取文件 if(option = JFileChooser.APPROVE_OPTION / 取得选择的文件 File file = fileChooser.getSelectedFile(; / 在标题栏上设定文件名称 setTitle(file.toString(; try / 建立文件 file.createNewFile(; / 进行文件保存 saveFile(; cat