创建一个注册窗口通过java

import javax.swing.*;
import java.awt.*;
import java.awt.event.ActionEvent;
import java.awt.event.ActionListener;

public class RegisterWindow extends JFrame implements ActionListener {
private JLabel nameLabel, emailLabel, passwordLabel, confirmPasswordLabel;
private JTextField nameField, emailField;
private JPasswordField passwordField, confirmPasswordField;
private JButton registerButton;
private JCheckBox agreeCheckBox;

public RegisterWindow() {
setTitle("注册");
setSize(400, 300);
setLocationRelativeTo(null);
setDefaultCloseOperation(JFrame.EXIT_ON_CLOSE);

JPanel mainPanel = new JPanel();
mainPanel.setLayout(new BorderLayout());

JPanel formPanel = new JPanel();
formPanel.setLayout(new GridLayout(5, 2, 5, 10));

nameLabel = new JLabel("用户名");
formPanel.add(nameLabel);

nameField = new JTextField();
formPanel.add(nameField);

emailLabel = new JLabel("电子邮箱");
formPanel.add(emailLabel);

emailField = new JTextField();
formPanel.add(emailField);

passwordLabel = new JLabel("密码");
formPanel.add(passwordLabel);

passwordField = new JPasswordField();
formPanel.add(passwordField);

confirmPasswordLabel = new JLabel("确认密码");
formPanel.add(confirmPasswordLabel);

confirmPasswordField = new JPasswordField();
formPanel.add(confirmPasswordField);

agreeCheckBox = new JCheckBox("同意协议");
formPanel.add(agreeCheckBox);

registerButton = new JButton("注册");
registerButton.addActionListener(this);
formPanel.add(registerButton);

mainPanel.add(formPanel, BorderLayout.CENTER);

setContentPane(mainPanel);
setVisible(true);
}

@Override
public void actionPerformed(ActionEvent e) {
if (e.getSource() == registerButton) {
String name = nameField.getText();
String email = emailField.getText();
String password = new String(passwordField.getPassword());
String confirmPassword = new String(confirmPasswordField.getPassword());
boolean agree = agreeCheckBox.isSelected();

if (name.trim().equals("") || email.trim().equals("") || password.trim().equals("")) {
JOptionPane.showMessageDialog(this, "请填写完整信息");
return;
}

if (!password.equals(confirmPassword)) {
JOptionPane.showMessageDialog(this, "两次密码不一致");
return;
}

if (!agree) {
JOptionPane.showMessageDialog(this, "请同意协议");
return;
}

JOptionPane.showMessageDialog(this, "注册成功");
}
}

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