public void actionPerformed(ActionEvent e) { dispose(); new RegisterFrame().setVisible(true); } }); buttonPanel.add(loginButton); buttonPanel.add(registerButton); mainPanel.add(inputPanel, BorderLayout.CENTER); mainPanel.add(captchaPanel, BorderLayout.NORTH); mainPanel.add(buttonPanel, BorderLayout.SOUTH); setContentPane(mainPanel); } private boolean authenticate(String username, String password) { // TODO: Check if username and password are valid. return true; } private String generateCaptcha() { Random random = new Random(); StringBuilder captchaBuilder = new StringBuilder(); int captchaLength = 4; for (int i = 0; i < captchaLength; i++) { captchaBuilder.append(random.nextInt(10)); } return captchaBuilder.toString(); } private Image createCaptchaImage(String captcha) { int width = 100; int height = 30; BufferedImage image = new BufferedImage(width, height, BufferedImage.TYPE_INT请根据上述代码续写满足下列要求的代码用java编写一个图形界面，右上角有登入按钮，点击后出现新界面，有登入和注册功能，若不存在账号提示注册，若存在账号，密码错误提示重新输入，包含验证码，不用第三方生成验证码，给出大致代码 点

好的，我来续写一下。根据您的要求，我来给出一个大致的代码示例： ```java import javax.swing.*; import java.awt.*; import java.awt.event.ActionEvent; import java.awt.event.ActionListener; import java.awt.image.BufferedImage; import java.util.Random; public class LoginFrame extends JFrame { private JTextField usernameField; private JPasswordField passwordField; private JTextField captchaField; private JLabel captchaLabel; public LoginFrame() { setTitle("Login"); setSize(400, 200); setDefaultCloseOperation(JFrame.EXIT_ON_CLOSE); JPanel mainPanel = new JPanel(new BorderLayout()); // 创建输入面板 JPanel inputPanel = new JPanel(new GridLayout(3, 2)); inputPanel.add(new JLabel("Username:")); usernameField = new JTextField(20); inputPanel.add(usernameField); inputPanel.add(new JLabel("Password:")); passwordField = new JPasswordField(20); inputPanel.add(passwordField); inputPanel.add(new JLabel("Captcha:")); captchaField = new JTextField(10); inputPanel.add(captchaField); // 创建验证码面板 JPanel captchaPanel = new JPanel(new FlowLayout(FlowLayout.CENTER)); captchaLabel = new JLabel(); updateCaptcha(); captchaPanel.add(captchaLabel); // 创建按钮面板 JPanel buttonPanel = new JPanel(new GridLayout(1, 2)); JButton loginButton = new JButton("Login"); loginButton.addActionListener(new ActionListener() { public void actionPerformed(ActionEvent e) { String username = usernameField.getText(); String password = new String(passwordField.getPassword()); String captcha = captchaField.getText(); // 验证码不正确 if (!captcha.equals(getCaptcha())) { JOptionPane.showMessageDialog(null, "Invalid captcha!", "Error", JOptionPane.ERROR_MESSAGE); updateCaptcha(); captchaField.setText(""); return; } // 用户名或密码不正确 if (!authenticate(username, password)) { JOptionPane.showMessageDialog(null, "Invalid username or password!", "Error", JOptionPane.ERROR_MESSAGE); passwordField.setText(""); updateCaptcha(); captchaField.setText(""); return; } // 登录成功 JOptionPane.showMessageDialog(null, "Login successful!", "Success", JOptionPane.INFORMATION_MESSAGE); dispose(); } }); JButton registerButton = new JButton("Register"); registerButton.addActionListener(new ActionListener() { public void actionPerformed(ActionEvent e) { dispose(); new RegisterFrame().setVisible(true); } }); buttonPanel.add(loginButton); buttonPanel.add(registerButton); mainPanel.add(inputPanel, BorderLayout.CENTER); mainPanel.add(captchaPanel, BorderLayout.NORTH); mainPanel.add(buttonPanel, BorderLayout.SOUTH); setContentPane(mainPanel); } // 验证用户名和密码是否正确 private boolean authenticate(String username, String password) { // TODO: Check if username and password are valid. return true; } // 生成随机验证码 private String generateCaptcha() { Random random = new Random(); StringBuilder captchaBuilder = new StringBuilder(); int captchaLength = 4; for (int i = 0; i < captchaLength; i++) { captchaBuilder.append(random.nextInt(10)); } return captchaBuilder.toString(); } // 更新验证码 private void updateCaptcha() { String captcha = generateCaptcha(); setCaptcha(captcha); setImage(createCaptchaImage(captcha)); } // 获取当前验证码 private String getCaptcha() { return captchaLabel.getText(); } // 设置当前验证码 private void setCaptcha(String captcha) { captchaLabel.setText(captcha); } // 创建验证码图片 private Image createCaptchaImage(String captcha) { int width = 100; int height = 30; BufferedImage image = new BufferedImage(width, height, BufferedImage.TYPE_INT_RGB); Graphics2D g = image.createGraphics(); // 设置背景色 g.setColor(Color.WHITE); g.fillRect(0, 0, width, height); // 画干扰线 Random random = new Random(); for (int i = 0; i < 5; i++) { int x1 = random.nextInt(width); int y1 = random.nextInt(height); int x2 = random.nextInt(width); int y2 = random.nextInt(height); g.setColor(Color.LIGHT_GRAY); g.drawLine(x1, y1, x2, y2); } // 画验证码 g.setFont(new Font("Arial", Font.BOLD, 20)); for (int i = 0; i < captcha.length(); i++) { int x = i * (width / captcha.length()) + 10; int y = 20 + random.nextInt(10); g.setColor(new Color(random.nextInt(256), random.nextInt(256), random.nextInt(256))); g.drawString(String.valueOf(captcha.charAt(i)), x, y); } g.dispose(); return image; } // 设置验证码图片 private void setImage(Image image) { ImageIcon icon = new ImageIcon(image); captchaLabel.setIcon(icon); } public static void main(String[] args) { LoginFrame frame = new LoginFrame(); frame.setVisible(true); } } ``` 代码中的注释会解释每个部分的作用。需要注意的是，为了实现验证码功能，我们需要使用一个JLabel组件来显示验证码图片，并使用一个ImageIcon对象来设置图片。我们还需要重写createCaptchaImage()方法来生成验证码图片，并添加updateCaptcha()方法来更新验证码。在登录时，我们需要先检查验证码是否正确，然后再检查用户名和密码是否正确。如果验证失败，我们需要显示错误提示框，并更新验证码。如果验证成功，我们可以关闭当前窗口并显示登录成功的提示框。