利用java+swing+jdbc做一个登陆注册页面并将数据保存mysql，代码

以下是一个简单的Java Swing登录注册页面并将数据保存到MySQL数据库的示例代码：

首先需要创建一个数据库表来存储用户信息，可以使用以下SQL语句：

CREATE TABLE `user` (
  `id` int(11) NOT NULL AUTO_INCREMENT,
  `username` varchar(50) NOT NULL,
  `password` varchar(50) NOT NULL,
  PRIMARY KEY (`id`)
) ENGINE=InnoDB DEFAULT CHARSET=utf8;

然后，创建一个Java项目并添加MySQL驱动程序（如mysql-connector-java-8.0.25.jar）到项目中。

接下来，我们需要创建一个包含登录和注册功能的Java Swing GUI。以下是一个简单的实现：

import java.awt.*;
import java.awt.event.*;
import java.sql.*;
import javax.swing.*;

public class LoginRegistrationForm extends JFrame implements ActionListener {
    // 登录窗口组件
    private JLabel loginLabel = new JLabel("登录");
    private JLabel usernameLabel = new JLabel("用户名:");
    private JLabel passwordLabel = new JLabel("密码:");
    private JTextField usernameField = new JTextField(20);
    private JPasswordField passwordField = new JPasswordField(20);
    private JButton loginButton = new JButton("登录");

    // 注册窗口组件
    private JLabel registrationLabel = new JLabel("注册");
    private JLabel newUsernameLabel = new JLabel("用户名:");
    private JLabel newPasswordLabel = new JLabel("密码:");
    private JTextField newUsernameField = new JTextField(20);
    private JPasswordField newPasswordField = new JPasswordField(20);
    private JButton registrationButton = new JButton("注册");

    // 数据库连接属性
    private String URL = "jdbc:mysql://localhost:3306/mydb";
    private String USERNAME = "root";
    private String PASSWORD = "password";
    private Connection connection = null;

    public LoginRegistrationForm() {
        super("登录/注册");

        // 创建数据库连接
        try {
            connection = DriverManager.getConnection(URL, USERNAME, PASSWORD);
        } catch (SQLException e) {
            e.printStackTrace();
        }

        // 设置窗口组件
        setSize(400, 300);
        setDefaultCloseOperation(JFrame.EXIT_ON_CLOSE);
        setLayout(new GridLayout(3, 1));

        // 添加登录窗口组件
        JPanel loginPanel = new JPanel(new GridLayout(3, 2));
        loginPanel.add(loginLabel);
        loginPanel.add(new JLabel(""));
        loginPanel.add(usernameLabel);
        loginPanel.add(usernameField);
        loginPanel.add(passwordLabel);
        loginPanel.add(passwordField);
        loginButton.addActionListener(this);
        loginPanel.add(loginButton);
        add(loginPanel);

        // 添加注册窗口组件
        JPanel registrationPanel = new JPanel(new GridLayout(3, 2));
        registrationPanel.add(registrationLabel);
        registrationPanel.add(new JLabel(""));
        registrationPanel.add(newUsernameLabel);
        registrationPanel.add(newUsernameField);
        registrationPanel.add(newPasswordLabel);
        registrationPanel.add(newPasswordField);
        registrationButton.addActionListener(this);
        registrationPanel.add(registrationButton);
        add(registrationPanel);

        setVisible(true);
    }

    @Override
    public void actionPerformed(ActionEvent e) {
        if (e.getSource() == loginButton) {
            // 验证登录信息
            String username = usernameField.getText();
            String password = String.valueOf(passwordField.getPassword());
            try {
                PreparedStatement statement = connection.prepareStatement(
                    "SELECT * FROM user WHERE username=? AND password=?"
                );
                statement.setString(1, username);
                statement.setString(2, password);
                ResultSet resultSet = statement.executeQuery();
                if (resultSet.next()) {
                    JOptionPane.showMessageDialog(
                        this, "登录成功", "提示", JOptionPane.INFORMATION_MESSAGE);
                } else {
                    JOptionPane.showMessageDialog(
                        this, "用户名或密码错误", "错误", JOptionPane.ERROR_MESSAGE);
                }
            } catch (SQLException ex) {
                ex.printStackTrace();
            }
        } else if (e.getSource() == registrationButton) {
            // 插入新用户信息
            String newUsername = newUsernameField.getText();
            String newPassword = String.valueOf(newPasswordField.getPassword());
            try {
                PreparedStatement statement = connection.prepareStatement(
                    "INSERT INTO user (username, password) VALUES (?, ?)"
                );
                statement.setString(1, newUsername);
                statement.setString(2, newPassword);
                int rowsInserted = statement.executeUpdate();
                if (rowsInserted > 0) {
                    JOptionPane.showMessageDialog(
                        this, "注册成功", "提示", JOptionPane.INFORMATION_MESSAGE);
                }
            } catch (SQLException ex) {
                ex.printStackTrace();
            }
        }
    }

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

这段代码创建了一个包含登录和注册功能的Java Swing GUI。当用户点击登录按钮时，程序将验证用户输入的用户名和密码是否存在于数据库中。当用户点击注册按钮时，程序将在数据库中插入新的用户信息。

注意，这个示例代码只是一个简单的实现，实际应用中需要更多的安全性和错误处理。