Javaを使用して倉庫管理のマルチユーザーログイン機能を実装する方法

CREATE TABLE `user` (
  `id` int(11) NOT NULL AUTO_INCREMENT,
  `username` varchar(50) NOT NULL,
  `password` varchar(50) NOT NULL,
  PRIMARY KEY (`id`)
);

import java.sql.Connection;
import java.sql.DriverManager;
import java.sql.PreparedStatement;
import java.sql.ResultSet;
import java.sql.SQLException;

public class UserLogin {
    // 数据库连接信息
    private String url = "jdbc:mysql://localhost:3306/your_database_name";
    private String username = "your_username";
    private String password = "your_password";

    // 用户注册方法
    public void register(String username, String password) {
        try (Connection conn = DriverManager.getConnection(url, username, password);
             PreparedStatement stmt = conn.prepareStatement("INSERT INTO user (username, password) VALUES (?, ?)")) {
            stmt.setString(1, username);
            stmt.setString(2, password);
            stmt.executeUpdate();
            System.out.println("用户注册成功！");
        } catch (SQLException e) {
            e.printStackTrace();
        }
    }

    // 用户登录方法
    public void login(String username, String password) {
        try (Connection conn = DriverManager.getConnection(url, username, password);
             PreparedStatement stmt = conn.prepareStatement("SELECT * FROM user WHERE username=? AND password=?")) {
            stmt.setString(1, username);
            stmt.setString(2, password);
            ResultSet rs = stmt.executeQuery();
            if (rs.next()) {
                System.out.println("用户登录成功！");
            } else {
                System.out.println("用户名或密码错误，请重新登录！");
            }
        } catch (SQLException e) {
            e.printStackTrace();
        }
    }

    public static void main(String[] args) {
        UserLogin userLogin = new UserLogin();
        userLogin.register("admin", "admin123");
        userLogin.login("admin", "admin123");
    }
}