java代码 用图形界面实现一个简单的文本记事本，能实现编辑、保存、另存为、查找、替换等功能

好的，以下是一个简单的Java代码，使用图形界面实现文本记事本的编辑、保存、另存为、查找和替换功能。其中，编辑功能包括新建、打开和保存文件，查找和替换功能使用Java的正则表达式。

import java.awt.*;
import java.awt.event.*;
import java.io.*;
import java.util.regex.*;
import javax.swing.*;
import javax.swing.filechooser.*;

public class TextEditor extends JFrame implements ActionListener {
    
    private JTextArea area = new JTextArea(20, 120);
    private JFileChooser dialog = new JFileChooser(System.getProperty("user.dir"));
    private String currentFile = "Untitled";
    private boolean changed = false;
    
    public TextEditor() {
        area.setFont(new Font("Monospaced", Font.PLAIN, 12));
        JScrollPane scroll = new JScrollPane(area, JScrollPane.VERTICAL_SCROLLBAR_ALWAYS, JScrollPane.HORIZONTAL_SCROLLBAR_ALWAYS);
        add(scroll, BorderLayout.CENTER);
        
        JMenuBar menuBar = new JMenuBar();
        setJMenuBar(menuBar);
        
        JMenu file = new JMenu("File");
        menuBar.add(file);
        
        JMenuItem newFile = new JMenuItem("New");
        newFile.addActionListener(this);
        file.add(newFile);
        
        JMenuItem openFile = new JMenuItem("Open");
        openFile.addActionListener(this);
        file.add(openFile);
        
        JMenuItem saveFile = new JMenuItem("Save");
        saveFile.addActionListener(this);
        file.add(saveFile);
        
        JMenuItem saveAsFile = new JMenuItem("Save As...");
        saveAsFile.addActionListener(this);
        file.add(saveAsFile);
        
        file.addSeparator();
        
        JMenuItem exit = new JMenuItem("Exit");
        exit.addActionListener(this);
        file.add(exit);
        
        JMenu edit = new JMenu("Edit");
        menuBar.add(edit);
        
        JMenuItem find = new JMenuItem("Find");
        find.addActionListener(this);
        edit.add(find);
        
        JMenuItem replace = new JMenuItem("Replace");
        replace.addActionListener(this);
        edit.add(replace);
        
        setDefaultCloseOperation(EXIT_ON_CLOSE);
        pack();
        area.addKeyListener(k1);
        setTitle(currentFile);
        setVisible(true);
    }
    
    private KeyListener k1 = new KeyAdapter() {
        public void keyPressed(KeyEvent e) {
            changed = true;
            setTitle("*" + currentFile);
        }
    };
    
    public void actionPerformed(ActionEvent e) {
        String cmd = e.getActionCommand();
        if (cmd.equals("New")) {
            new TextEditor();
        } else if (cmd.equals("Open")) {
            if (dialog.showOpenDialog(null) == JFileChooser.APPROVE_OPTION) {
                readInFile(dialog.getSelectedFile().getAbsolutePath());
            }
        } else if (cmd.equals("Save")) {
            if (!currentFile.equals("Untitled")) {
                saveToFile(currentFile);
            } else {
                saveAsFile();
            }
        } else if (cmd.equals("Save As...")) {
            saveAsFile();
        } else if (cmd.equals("Exit")) {
            if (changed) {
                int confirm = JOptionPane.showConfirmDialog(null, "Are you sure you want to exit without saving?", "Confirm Exit", JOptionPane.YES_NO_CANCEL_OPTION);
                if (confirm == JOptionPane.YES_OPTION) {
                    dispose();
                } else if (confirm == JOptionPane.NO_OPTION) {
                    saveAsFile();
                    dispose();
                }
            } else {
                dispose();
            }
        } else if (cmd.equals("Find")) {
            String find = JOptionPane.showInputDialog(null, "Find:");
            if (find != null) {
                Pattern pattern = Pattern.compile(find);
                Matcher matcher = pattern.matcher(area.getText());
                if (matcher.find()) {
                    area.setCaretPosition(matcher.start());
                    area.setSelectionStart(matcher.start());
                    area.setSelectionEnd(matcher.end());
                }
            }
        } else if (cmd.equals("Replace")) {
            String find = JOptionPane.showInputDialog(null, "Find:");
            if (find != null) {
                String replace = JOptionPane.showInputDialog(null, "Replace with:");
                if (replace != null) {
                    Pattern pattern = Pattern.compile(find);
                    Matcher matcher = pattern.matcher(area.getText());
                    if (matcher.find()) {
                        area.replaceRange(replace, matcher.start(), matcher.end());
                    }
                }
            }
        }
    }
    
    private void readInFile(String fileName) {
        try {
            FileReader r = new FileReader(fileName);
            area.read(r, null);
            r.close();
            currentFile = fileName;
            setTitle(currentFile);
            changed = false;
        } catch (IOException e) {
            Toolkit.getDefaultToolkit().beep();
            JOptionPane.showMessageDialog(null, "Could not open file: " + fileName, "Error", JOptionPane.ERROR_MESSAGE);
        }
    }
    
    private void saveToFile(String fileName) {
        try {
            FileWriter w = new FileWriter(fileName);
            area.write(w);
            w.close();
            currentFile = fileName;
            setTitle(currentFile);
            changed = false;
        } catch (IOException e) {
            Toolkit.getDefaultToolkit().beep();
            JOptionPane.showMessageDialog(null, "Could not save file: " + fileName, "Error", JOptionPane.ERROR_MESSAGE);
        }
    }
    
    private void saveAsFile() {
        if (dialog.showSaveDialog(null) == JFileChooser.APPROVE_OPTION) {
            saveToFile(dialog.getSelectedFile().getAbsolutePath());
        }
    }
    
    public static void main(String[] args) {
        new TextEditor();
    }
}

希望可以帮助到你！