java编写记事本程序

好的，我可以为您提供一个简单的Java记事本程序的框架，您可以根据您的需求进行修改和扩展。

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

public class SimpleNotepad extends Frame implements ActionListener {

    private TextArea textArea;
    private MenuBar menuBar;
    private Menu fileMenu, editMenu;
    private MenuItem newMenuItem, openMenuItem, saveMenuItem, exitMenuItem, cutMenuItem, copyMenuItem, pasteMenuItem;

    public SimpleNotepad() {
        setTitle("Simple Notepad");
        setSize(500, 500);
        setLocationRelativeTo(null);

        textArea = new TextArea();
        add(textArea);

        menuBar = new MenuBar();

        fileMenu = new Menu("File");
        newMenuItem = new MenuItem("New");
        openMenuItem = new MenuItem("Open");
        saveMenuItem = new MenuItem("Save");
        exitMenuItem = new MenuItem("Exit");
        fileMenu.add(newMenuItem);
        fileMenu.add(openMenuItem);
        fileMenu.add(saveMenuItem);
        fileMenu.addSeparator();
        fileMenu.add(exitMenuItem);

        editMenu = new Menu("Edit");
        cutMenuItem = new MenuItem("Cut");
        copyMenuItem = new MenuItem("Copy");
        pasteMenuItem = new MenuItem("Paste");
        editMenu.add(cutMenuItem);
        editMenu.add(copyMenuItem);
        editMenu.add(pasteMenuItem);

        menuBar.add(fileMenu);
        menuBar.add(editMenu);

        setMenuBar(menuBar);

        newMenuItem.addActionListener(this);
        openMenuItem.addActionListener(this);
        saveMenuItem.addActionListener(this);
        exitMenuItem.addActionListener(this);
        cutMenuItem.addActionListener(this);
        copyMenuItem.addActionListener(this);
        pasteMenuItem.addActionListener(this);

        addWindowListener(new WindowAdapter() {
            public void windowClosing(WindowEvent e) {
                dispose();
            }
        });
    }

    public void actionPerformed(ActionEvent e) {
        if (e.getSource() == newMenuItem) {
            textArea.setText("");
        } else if (e.getSource() == openMenuItem) {
            FileDialog fileDialog = new FileDialog(this, "Open File", FileDialog.LOAD);
            fileDialog.setVisible(true);
            if (fileDialog.getFile() != null) {
                String fileName = fileDialog.getDirectory() + fileDialog.getFile();
                setTitle(fileName);
                readFile(fileName);
            }
        } else if (e.getSource() == saveMenuItem) {
            FileDialog fileDialog = new FileDialog(this, "Save File", FileDialog.SAVE);
            fileDialog.setVisible(true);
            if (fileDialog.getFile() != null) {
                String fileName = fileDialog.getDirectory() + fileDialog.getFile();
                setTitle(fileName);
                saveFile(fileName);
            }
        } else if (e.getSource() == exitMenuItem) {
            dispose();
        } else if (e.getSource() == cutMenuItem) {
            textArea.cut();
        } else if (e.getSource() == copyMenuItem) {
            textArea.copy();
        } else if (e.getSource() == pasteMenuItem) {
            textArea.paste();
        }
    }

    private void readFile(String fileName) {
        try {
            BufferedReader reader = new BufferedReader(new FileReader(fileName));
            String line = null;
            while ((line = reader.readLine()) != null) {
                textArea.append(line + "\n");
            }
            reader.close();
        } catch (IOException e) {
            e.printStackTrace();
        }
    }

    private void saveFile(String fileName) {
        try {
            BufferedWriter writer = new BufferedWriter(new FileWriter(fileName));
            writer.write(textArea.getText());
            writer.close();
        } catch (IOException e) {
            e.printStackTrace();
        }
    }

    public static void main(String[] args) {
        SimpleNotepad notepad = new SimpleNotepad();
        notepad.setVisible(true);
    }
}

这个程序提供了基本的记事本功能，包括打开、保存、剪切、复制和粘贴。您可以根据您的需要进行修改和扩展，例如添加其他菜单项或功能。