Javaを使用してCMSシステムのマルチユーザーログイン機能を実装する方法

public class User {
    private String username;
    private String password;
    private Role role;

    public User(String username, String password, Role role) {
        this.username = username;
        this.password = password;
        this.role = role;
    }

    // 省略getter和setter方法
}

public enum Role {
    ADMIN,
    EDITOR,
    READER
}

import java.util.ArrayList;
import java.util.List;

public class UserDatabase {
    private static List<User> users = new ArrayList<>();

    static {
        users.add(new User("admin", "admin123", Role.ADMIN));
        users.add(new User("editor", "editor123", Role.EDITOR));
        users.add(new User("reader", "reader123", Role.READER));
    }

    public static User getUser(String username) {
        for (User user : users) {
            if (user.getUsername().equals(username)) {
                return user;
            }
        }
        return null;
    }
}

import java.util.Scanner;

public class LoginService {
    private static final String WELCOME_MESSAGE = "欢迎使用CMS系统！";
    private static final String LOGIN_MESSAGE = "请输入用户名和密码进行登录：";
    private static final String INVALID_CREDENTIALS_MESSAGE = "用户名或密码错误，请重新输入。";

    public void login() {
        System.out.println(WELCOME_MESSAGE);
        System.out.println(LOGIN_MESSAGE);

        Scanner scanner = new Scanner(System.in);
        String username = scanner.nextLine();
        String password = scanner.nextLine();

        User user = UserDatabase.getUser(username);

        if (user != null && user.getPassword().equals(password)) {
            System.out.println("登录成功！");

            switch (user.getRole()) {
                case ADMIN:
                    // 管理员的逻辑处理
                    break;
                case EDITOR:
                    // 编辑者的逻辑处理
                    break;
                case READER:
                    // 读者的逻辑处理
                    break;
            }
        } else {
            System.out.println(INVALID_CREDENTIALS_MESSAGE);
        }
    }

    public static void main(String[] args) {
        LoginService loginService = new LoginService();
        loginService.login();
    }
}