仿照Windows中的记事本，编写一个Java程序记事本。代码要求：有打开和保存文本文件，设置字体功能

好的，我可以为您提供一个简单的Java程序记事本，实现打开和保存文本文件的功能，以及设置字体的功能。

代码如下：

import java.awt.BorderLayout;
import java.awt.Font;
import java.awt.event.ActionEvent;
import java.awt.event.ActionListener;
import java.io.BufferedReader;
import java.io.BufferedWriter;
import java.io.File;
import java.io.FileReader;
import java.io.FileWriter;
import javax.swing.*;

public class JavaNotepad extends JFrame implements ActionListener {
    private JTextArea textArea;
    private JFileChooser fileChooser;
    private Font font;

    public JavaNotepad() {
        super("Java Notepad");

        // 创建菜单栏
        JMenuBar menuBar = new JMenuBar();

        // 创建文件菜单
        JMenu fileMenu = new JMenu("文件");
        JMenuItem openMenuItem = new JMenuItem("打开");
        openMenuItem.addActionListener(this);
        JMenuItem saveMenuItem = new JMenuItem("保存");
        saveMenuItem.addActionListener(this);
        fileMenu.add(openMenuItem);
        fileMenu.add(saveMenuItem);

        // 创建格式菜单
        JMenu formatMenu = new JMenu("格式");
        JMenuItem fontMenuItem = new JMenuItem("字体");
        fontMenuItem.addActionListener(this);
        formatMenu.add(fontMenuItem);

        // 将菜单栏添加到窗口中
        menuBar.add(fileMenu);
        menuBar.add(formatMenu);
        setJMenuBar(menuBar);

        // 创建文本区域
        textArea = new JTextArea();
        add(new JScrollPane(textArea), BorderLayout.CENTER);

        // 创建文件选择器
        fileChooser = new JFileChooser();

        // 设置窗口大小和可见性
        setSize(800, 600);
        setVisible(true);
    }

    // 处理菜单项的动作
    public void actionPerformed(ActionEvent e) {
        String command = e.getActionCommand();
        if (command.equals("打开")) {
            int result = fileChooser.showOpenDialog(this);
            if (result == JFileChooser.APPROVE_OPTION) {
                File file = fileChooser.getSelectedFile();
                try {
                    BufferedReader reader = new BufferedReader(new FileReader(file));
                    String line = null;
                    while ((line = reader.readLine()) != null) {
                        textArea.append(line + "\n");
                    }
                    reader.close();
                } catch (Exception ex) {
                    ex.printStackTrace();
                }
            }
        } else if (command.equals("保存")) {
            int result = fileChooser.showSaveDialog(this);
            if (result == JFileChooser.APPROVE_OPTION) {
                File file = fileChooser.getSelectedFile();
                try {
                    BufferedWriter writer = new BufferedWriter(new FileWriter(file));
                    writer.write(textArea.getText());
                    writer.close();
                } catch (Exception ex) {
                    ex.printStackTrace();
                }
            }
        } else if (command.equals("字体")) {
            font = JFontChooser.showDialog(this, "选择字体", font);
            if (font != null) {
                textArea.setFont(font);
            }
        }
    }

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

// 字体选择器
class JFontChooser extends JPanel implements ActionListener {
    private static final long serialVersionUID = 1L;
    private static JDialog dialog;
    private static Font font;
    private static JLabel previewLabel;
    private static JComboBox<String> fontNameComboBox;
    private static JComboBox<String> fontStyleComboBox;
    private static JComboBox<Integer> fontSizeComboBox;
    private static JButton okButton;
    private static JButton cancelButton;

    public JFontChooser() {
        super(new BorderLayout());

        // 字体名称选择框
        GraphicsEnvironment env = GraphicsEnvironment.getLocalGraphicsEnvironment();
        String[] fontNames = env.getAvailableFontFamilyNames();
        fontNameComboBox = new JComboBox<String>(fontNames);
        fontNameComboBox.setSelectedItem(font.getName());

        // 字体样式选择框
        String[] fontStyles = {"常规", "粗体", "斜体", "粗斜体"};
        fontStyleComboBox = new JComboBox<String>(fontStyles);
        fontStyleComboBox.setSelectedIndex(font.getStyle());

        // 字体大小选择框
        Integer[] fontSizes = {8, 9, 10, 11, 12, 14, 16, 18, 20, 22, 24, 26, 28, 36, 48, 72};
        fontSizeComboBox = new JComboBox<Integer>(fontSizes);
        fontSizeComboBox.setSelectedItem(font.getSize());

        // 预览标签
        previewLabel = new JLabel("这是一个字体预览标签", JLabel.CENTER);
        previewLabel.setFont(font);

        // 确定和取消按钮
        okButton = new JButton("确定");
        okButton.addActionListener(this);
        cancelButton = new JButton("取消");
        cancelButton.addActionListener(this);

        // 创建面板
        JPanel panel1 = new JPanel(new GridLayout(3, 2));
        panel1.add(new JLabel("字体名称："));
        panel1.add(fontNameComboBox);
        panel1.add(new JLabel("字体样式："));
        panel1.add(fontStyleComboBox);
        panel1.add(new JLabel("字体大小："));
        panel1.add(fontSizeComboBox);
        JPanel panel2 = new JPanel(new BorderLayout());
        panel2.add(previewLabel, BorderLayout.CENTER);
        JPanel panel3 = new JPanel(new FlowLayout());
        panel3.add(okButton);
        panel3.add(cancelButton);

        // 将面板添加到窗口中
        add(panel1, BorderLayout.NORTH);
        add(panel2, BorderLayout.CENTER);
        add(panel3, BorderLayout.SOUTH);
    }

    // 显示字体选择器对话框
    public static Font showDialog(JFrame parent, String title, Font font) {
        JFontChooser.font = font;
        dialog = new JDialog(parent, title, true);
        dialog.setDefaultCloseOperation(JDialog.DISPOSE_ON_CLOSE);
        dialog.getContentPane().add(new JFontChooser());
        dialog.pack();
        dialog.setLocationRelativeTo(parent);
        dialog.setVisible(true);
        return JFontChooser.font;
    }

    // 处理按钮的动作
    public void actionPerformed(ActionEvent e) {
        if (e.getSource() == okButton) {
            String fontName = (String)fontNameComboBox.getSelectedItem();
            int fontStyle = fontStyleComboBox.getSelectedIndex();
            int fontSize = (Integer)fontSizeComboBox.getSelectedItem();
            font = new Font(fontName, fontStyle, fontSize);
            previewLabel.setFont(font);
            dialog.dispose();
        } else if (e.getSource() == cancelButton) {
            dialog.dispose();
        }
    }
}

这个Java记事本程序使用了Swing组件，包括JFrame、JMenuBar、JMenu、JMenuItem、JTextArea、JScrollPane、JFileChooser、JLabel、JComboBox、JButton等。它提供了打开、保存和设置字体的功能。您可以根据自己的需求进行修改和扩展。