分别写出用户类，管理员类，汽车类

在面向对象的设计中，用户类、管理员类和汽车类是常见的基础组件。下面分别给出简化的Java类定义示例：

1. **用户(User)类**:

import javax.persistence.Entity;
import javax.persistence.GeneratedValue;
import javax.persistence.GenerationType;
import javax.persistence.Id;

@Entity
public class User {

    @Id
    @GeneratedValue(strategy = GenerationType.AUTO)
    private Long id;
    private String username;
    private String password;
    private boolean isVip; // VIP用户标识

    // 构造函数，getter和setter方法
    public User(String username, String password) {
        this.username = username;
        this.password = password;
        this.isVip = false; // 默认非VIP
    }

    // getter和setter方法...
}

2. **管理员(Administrator)类**:

import org.springframework.security.core.GrantedAuthority;
import org.springframework.security.core.userdetails.UserDetails;

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

public class Administrator implements UserDetails {

    private Long id;
    private String username;
    private String password;
    private List<GrantedAuthority> authorities; // 权限列表

    // 初始化方法, 构造函数和getter/setter...
    
    @Override
    public Collection<? extends GrantedAuthority> getAuthorities() {
        List<GrantedAuthority> grantedAuthorities = new ArrayList<>();
        grantedAuthorities.add(new SimpleGrantedAuthority("ADMIN"));
        return grantedAuthorities;
    }
    
    // 其他 UserDetails 接口方法...
}

3. **汽车(Vehicle)类**:

import javax.persistence.Entity;
import javax.persistence.GeneratedValue;
import javax.persistence.GenerationType;
import javax.persistence.Id;
import java.util.Date;

@Entity
public class Vehicle {

    @Id
    @GeneratedValue(strategy = GenerationType.AUTO)
    private Long id;
    private String modelName;
    private VehicleType type; // 汽车类型枚举 Car, Bus, Trunk
    private boolean isAvailable; // 是否可供租赁
    private Date lastMaintenanceDate; // 上次维护日期

    // 构造函数, getter和setter方法...
    public Vehicle(String modelName, VehicleType type) {
        this.modelName = modelName;
        this.type = type;
        this.isAvailable = true;
    }

    // ...其他属性和方法
}

enum VehicleType {
    CAR, BUS, TRUNK;
}

注意，这只是一个简化的例子，实际应用中可能需要更详细的字段和业务逻辑，例如用户和车辆之间的关联、权限管理的细节等。