Java小游戏登录注册连接数据库

好的，我可以为您提供一个简单的Java小游戏登录注册的示例代码，并连接到MySQL数据库。

1. 首先，您需要创建一个MySQL数据库，并创建一个名为“users”的表，其中包含以下列：

- id (INT, 主键)
- username (VARCHAR(50))
- password (VARCHAR(50))

2. 接下来，您需要下载MySQL JDBC驱动程序，并将其添加到您的Java项目中。

3. 创建一个名为“User”的Java类，该类具有以下属性和方法：

public class User {
    private int id;
    private String username;
    private String password;

    public User(int id, String username, String password) {
        this.id = id;
        this.username = username;
        this.password = password;
    }

    // Getters and setters for id, username, and password

    public static User getUserByUsername(String username) {
        // TODO: Query the database for a user with the given username
        // and return a new User object with the retrieved data
    }

    public boolean save() {
        // TODO: Insert a new row into the users table with the current
        // user's data, and return true if successful
    }

    public boolean update() {
        // TODO: Update the row in the users table with the current
        // user's data, and return true if successful
    }

    public boolean delete() {
        // TODO: Delete the row in the users table with the current
        // user's data, and return true if successful
    }
}

4. 创建一个名为“Database”的Java类，该类具有以下方法：

import java.sql.*;

public class Database {
    private Connection conn;

    public Database(String url, String user, String pass) {
        try {
            conn = DriverManager.getConnection(url, user, pass);
        } catch (SQLException e) {
            e.printStackTrace();
        }
    }

    public User getUserByUsername(String username) {
        User user = null;

        try {
            PreparedStatement stmt = conn.prepareStatement("SELECT * FROM users WHERE username = ?");
            stmt.setString(1, username);
            ResultSet rs = stmt.executeQuery();

            if (rs.next()) {
                user = new User(rs.getInt("id"), rs.getString("username"), rs.getString("password"));
            }

            rs.close();
            stmt.close();
        } catch (SQLException e) {
            e.printStackTrace();
        }

        return user;
    }

    public boolean saveUser(User user) {
        try {
            PreparedStatement stmt = conn.prepareStatement("INSERT INTO users (username, password) VALUES (?, ?)");
            stmt.setString(1, user.getUsername());
            stmt.setString(2, user.getPassword());
            int rowsAffected = stmt.executeUpdate();
            stmt.close();
            return rowsAffected > 0;
        } catch (SQLException e) {
            e.printStackTrace();
            return false;
        }
    }

    public boolean updateUser(User user) {
        try {
            PreparedStatement stmt = conn.prepareStatement("UPDATE users SET username = ?, password = ? WHERE id = ?");
            stmt.setString(1, user.getUsername());
            stmt.setString(2, user.getPassword());
            stmt.setInt(3, user.getId());
            int rowsAffected = stmt.executeUpdate();
            stmt.close();
            return rowsAffected > 0;
        } catch (SQLException e) {
            e.printStackTrace();
            return false;
        }
    }

    public boolean deleteUser(User user) {
        try {
            PreparedStatement stmt = conn.prepareStatement("DELETE FROM users WHERE id = ?");
            stmt.setInt(1, user.getId());
            int rowsAffected = stmt.executeUpdate();
            stmt.close();
            return rowsAffected > 0;
        } catch (SQLException e) {
            e.printStackTrace();
            return false;
        }
    }

    public void close() {
        try {
            conn.close();
        } catch (SQLException e) {
            e.printStackTrace();
        }
    }
}

5. 最后，您可以在您的游戏中使用这些类来实现注册和登录功能。例如：

import java.util.Scanner;

public class Game {
    private static Database db;

    public static void main(String[] args) {
        db = new Database("jdbc:mysql://localhost:3306/mydatabase", "root", "password");

        Scanner scanner = new Scanner(System.in);

        // Prompt the user to register or login
        System.out.print("Enter 1 to register, 2 to login: ");
        int choice = scanner.nextInt();

        if (choice == 1) {
            // Register a new user
            System.out.print("Enter a username: ");
            String username = scanner.next();
            System.out.print("Enter a password: ");
            String password = scanner.next();

            User user = new User(0, username, password);
            if (db.saveUser(user)) {
                System.out.println("User registered successfully!");
            } else {
                System.out.println("Failed to register user.");
            }
        } else if (choice == 2) {
            // Login with an existing user
            System.out.print("Enter your username: ");
            String username = scanner.next();
            System.out.print("Enter your password: ");
            String password = scanner.next();

            User user = db.getUserByUsername(username);
            if (user != null && user.getPassword().equals(password)) {
                System.out.println("Login successful!");
            } else {
                System.out.println("Invalid username or password.");
            }
        }

        scanner.close();
        db.close();
    }
}

这是一个简单的示例，您可以根据您的游戏需求进行修改和扩展。