仿照windows记事本，制作一个记事本软件，实现纯文本文件的新建、打开、保存、另存、复制、粘贴、查找、替换、关于等等功能；关闭软件是弹出对话框提示是否把修改保存，根据用户选择更新磁盘文件内容 java直接给出代码

以下是一个简单的Java记事本程序，实现了新建、打开、保存、另存、复制、粘贴、查找、替换、关于等功能：

import java.awt.BorderLayout;
import java.awt.Container;
import java.awt.Dimension;
import java.awt.FlowLayout;
import java.awt.Font;
import java.awt.event.ActionEvent;
import java.awt.event.ActionListener;
import java.awt.event.KeyEvent;
import java.awt.event.KeyListener;
import java.io.BufferedReader;
import java.io.File;
import java.io.FileReader;
import java.io.FileWriter;
import java.io.IOException;
import java.util.Scanner;

import javax.swing.Box;
import javax.swing.JButton;
import 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.JPanel;
import javax.swing.JScrollPane;
import javax.swing.JTextArea;
import javax.swing.KeyStroke;
import javax.swing.WindowConstants;

public class Notepad extends JFrame implements ActionListener, KeyListener {
    private static final long serialVersionUID = 1L;

    private JTextArea textArea;
    private JLabel statusLabel;
    private File currentFile;
    private boolean modified = false;

    public Notepad() {
        super("记事本");

        Container contentPane = getContentPane();

        textArea = new JTextArea();
        textArea.setFont(new Font("宋体", Font.PLAIN, 16));
        textArea.addKeyListener(this);

        JScrollPane scrollPane = new JScrollPane(textArea);

        statusLabel = new JLabel("就绪");
        statusLabel.setPreferredSize(new Dimension(200, 20));

        contentPane.add(scrollPane, BorderLayout.CENTER);
        contentPane.add(statusLabel, BorderLayout.SOUTH);

        JMenuBar menuBar = new JMenuBar();

        JMenu fileMenu = new JMenu("文件");

        JMenuItem newMenuItem = new JMenuItem("新建");
        newMenuItem.setAccelerator(KeyStroke.getKeyStroke(KeyEvent.VK_N, KeyEvent.CTRL_DOWN_MASK));
        newMenuItem.addActionListener(this);
        fileMenu.add(newMenuItem);

        JMenuItem openMenuItem = new JMenuItem("打开");
        openMenuItem.setAccelerator(KeyStroke.getKeyStroke(KeyEvent.VK_O, KeyEvent.CTRL_DOWN_MASK));
        openMenuItem.addActionListener(this);
        fileMenu.add(openMenuItem);

        JMenuItem saveMenuItem = new JMenuItem("保存");
        saveMenuItem.setAccelerator(KeyStroke.getKeyStroke(KeyEvent.VK_S, KeyEvent.CTRL_DOWN_MASK));
        saveMenuItem.addActionListener(this);
        fileMenu.add(saveMenuItem);

        JMenuItem saveAsMenuItem = new JMenuItem("另存为");
        saveAsMenuItem.addActionListener(this);
        fileMenu.add(saveAsMenuItem);

        menuBar.add(fileMenu);

        JMenu editMenu = new JMenu("编辑");

        JMenuItem copyMenuItem = new JMenuItem("复制");
        copyMenuItem.setAccelerator(KeyStroke.getKeyStroke(KeyEvent.VK_C, KeyEvent.CTRL_DOWN_MASK));
        copyMenuItem.addActionListener(this);
        editMenu.add(copyMenuItem);

        JMenuItem pasteMenuItem = new JMenuItem("粘贴");
        pasteMenuItem.setAccelerator(KeyStroke.getKeyStroke(KeyEvent.VK_V, KeyEvent.CTRL_DOWN_MASK));
        pasteMenuItem.addActionListener(this);
        editMenu.add(pasteMenuItem);

        JMenuItem findMenuItem = new JMenuItem("查找");
        findMenuItem.setAccelerator(KeyStroke.getKeyStroke(KeyEvent.VK_F, KeyEvent.CTRL_DOWN_MASK));
        findMenuItem.addActionListener(this);
        editMenu.add(findMenuItem);

        JMenuItem replaceMenuItem = new JMenuItem("替换");
        replaceMenuItem.setAccelerator(KeyStroke.getKeyStroke(KeyEvent.VK_H, KeyEvent.CTRL_DOWN_MASK));
        replaceMenuItem.addActionListener(this);
        editMenu.add(replaceMenuItem);

        menuBar.add(editMenu);

        JMenu helpMenu = new JMenu("帮助");

        JMenuItem aboutMenuItem = new JMenuItem("关于");
        aboutMenuItem.addActionListener(this);
        helpMenu.add(aboutMenuItem);

        menuBar.add(Box.createHorizontalGlue());
        menuBar.add(helpMenu);

        setJMenuBar(menuBar);

        JPanel buttonPanel = new JPanel(new FlowLayout(FlowLayout.RIGHT));

        JButton newButton = new JButton("新建");
        newButton.addActionListener(this);
        buttonPanel.add(newButton);

        JButton openButton = new JButton("打开");
        openButton.addActionListener(this);
        buttonPanel.add(openButton);

        JButton saveButton = new JButton("保存");
        saveButton.addActionListener(this);
        buttonPanel.add(saveButton);

        contentPane.add(buttonPanel, BorderLayout.NORTH);

        setDefaultCloseOperation(WindowConstants.DO_NOTHING_ON_CLOSE);
        addWindowListener(new java.awt.event.WindowAdapter() {
            public void windowClosing(java.awt.event.WindowEvent evt) {
                exitApplication();
            }
        });
        pack();
        setLocationRelativeTo(null);
        setVisible(true);
    }

    public static void main(String[] args) {
        new Notepad();
    }

    private void exitApplication() {
        if (modified) {
            int choice = JOptionPane.showConfirmDialog(this, "是否保存修改？", "记事本", JOptionPane.YES_NO_CANCEL_OPTION);
            if (choice == JOptionPane.YES_OPTION) {
                saveFile();
            } else if (choice == JOptionPane.CANCEL_OPTION) {
                return;
            }
        }
        dispose();
        System.exit(0);
    }

    private void newFile() {
        if (modified) {
            int choice = JOptionPane.showConfirmDialog(this, "是否保存修改？", "记事本", JOptionPane.YES_NO_CANCEL_OPTION);
            if (choice == JOptionPane.YES_OPTION) {
                saveFile();
            } else if (choice == JOptionPane.CANCEL_OPTION) {
                return;
            }
        }
        textArea.setText("");
        setTitle("无标题");
        currentFile = null;
        modified = false;
    }

    private void openFile() {
        if (modified) {
            int choice = JOptionPane.showConfirmDialog(this, "是否保存修改？", "记事本", JOptionPane.YES_NO_CANCEL_OPTION);
            if (choice == JOptionPane.YES_OPTION) {
                saveFile();
            } else if (choice == JOptionPane.CANCEL_OPTION) {
                return;
            }
        }
        JFileChooser fileChooser = new JFileChooser();
        int result = fileChooser.showOpenDialog(this);
        if (result == JFileChooser.APPROVE_OPTION) {
            File file = fileChooser.getSelectedFile();
            try {
                BufferedReader reader = new BufferedReader(new FileReader(file));
                String line;
                StringBuilder buffer = new StringBuilder();
                while ((line = reader.readLine()) != null) {
                    buffer.append(line).append("\n");
                }
                reader.close();
                textArea.setText(buffer.toString());
                setTitle(file.getAbsolutePath());
                currentFile = file;
                modified = false;
            } catch (IOException e) {
                JOptionPane.showMessageDialog(this, e.getMessage(), "错误", JOptionPane.ERROR_MESSAGE);
            }
        }
    }

    private void saveFile() {
        if (currentFile == null) {
            JFileChooser fileChooser = new JFileChooser();
            int result = fileChooser.showSaveDialog(this);
            if (result == JFileChooser.APPROVE_OPTION) {
                currentFile = fileChooser.getSelectedFile();
            } else {
                return;
            }
        }
        try {
            FileWriter writer = new FileWriter(currentFile);
            writer.write(textArea.getText());
            writer.close();
            setTitle(currentFile.getAbsolutePath());
            modified = false;
        } catch (IOException e) {
            JOptionPane.showMessageDialog(this, e.getMessage(), "错误", JOptionPane.ERROR_MESSAGE);
        }
    }

    private void saveFileAs() {
        JFileChooser fileChooser = new JFileChooser();
        int result = fileChooser.showSaveDialog(this);
        if (result == JFileChooser.APPROVE_OPTION) {
            currentFile = fileChooser.getSelectedFile();
            saveFile();
        }
    }

    private void copyText() {
        textArea.copy();
    }

    private void pasteText() {
        textArea.paste();
    }

    private void findText() {
        String text = JOptionPane.showInputDialog(this, "查找：", "记事本", JOptionPane.PLAIN_MESSAGE);
        if (text != null) {
            String content = textArea.getText();
            int index = content.indexOf(text);
            if (index == -1) {
                JOptionPane.showMessageDialog(this, "未找到指定文本。", "记事本", JOptionPane.INFORMATION_MESSAGE);
            } else {
                textArea.select(index, index + text.length());
            }
        }
    }

    private void replaceText() {
        String findText = JOptionPane.showInputDialog(this, "查找：", "记事本", JOptionPane.PLAIN_MESSAGE);
        if (findText != null) {
            String replaceText = JOptionPane.showInputDialog(this, "替换为：", "记事本", JOptionPane.PLAIN_MESSAGE);
            if (replaceText != null) {
                String content = textArea.getText();
                int index = content.indexOf(findText);
                if (index == -1) {
                    JOptionPane.showMessageDialog(this, "未找到指定文本。", "记事本", JOptionPane.INFORMATION_MESSAGE);
                } else {
                    textArea.replaceRange(replaceText, index, index + findText.length());
                    modified = true;
                }
            }
        }
    }

    private void about() {
        JOptionPane.showMessageDialog(this, "记事本\n\n版本：1.0\n开发者：xxx\n日期：2022年1月1日", "关于", JOptionPane.INFORMATION_MESSAGE);
    }

    @Override
    public void actionPerformed(ActionEvent e) {
        String command = e.getActionCommand();
        switch (command) {
            case "新建":
            case "新建(N)...":
            case "Ctrl+N":
                newFile();
                break;
            case "打开...":
            case "打开(O)...":
            case "Ctrl+O":
                openFile();
                break;
            case "保存":
            case "保存(S)":
            case "Ctrl+S":
                saveFile();
                break;
            case "另存为(A)...":
                saveFileAs();
                break;
            case "复制":
            case "复制(C)":
            case "Ctrl+C":
                copyText();
                break;
            case "粘贴":
            case "粘贴(P)":
            case "Ctrl+V":
                pasteText();
                break;
            case "查找...":
            case "查找(F)...":
            case "Ctrl+F":
                findText();
                break;
            case "替换...":
            case "替换(R)...":
            case "Ctrl+H":
                replaceText();
                break;
            case "关于记事本":
                about();
                break;
        }
    }

    @Override
    public void keyPressed(KeyEvent e) {
        if (e.getKeyCode() == KeyEvent.VK_ENTER || e.getKeyCode() == KeyEvent.VK_BACK_SPACE) {
            modified = true;
        }
    }

    @Override
    public void keyTyped(KeyEvent e) {
    }

    @Override
    public void keyReleased(KeyEvent e) {
        int length = textArea.getText().length();
        int caretPosition = textArea.getCaretPosition();
        statusLabel.setText(String.format("第 %d 行，第 %d 列，共 %d 个字符", textArea.getLineOfOffset(caretPosition) + 1,
                caretPosition - textArea.getLineStartOffset(textArea.getLineOfOffset(caretPosition)) + 1, length));
    }
}

注意，这只是一个简单的实现，可能存在一些漏洞和不足之处，需要根据实际需求进行改进。