Java基础一篇过（二）泛型这篇就够了

/**
 * 汽车类
 */
@Data
public class Car {
    /*无参构造*/
    public Car() {

    }

    /*带参构造*/
    public Car(int id, String name, String Type) {
        this.id = id;
        this.name = name;
        this.Type = Type;
    }

    /*属性*/
    private int id;//编号
    private String name;//名称
    private String Type;//类型
}

/**
 * 宠物类
 */
@Data
public class Pet {
    /*无参构造*/
    public Pet() {

    }

    /*带参构造*/
    public Pet(int id, String name, String Type) {
        this.id = id;
        this.name = name;
        this.Type = Type;
    }

    /*属性*/
    private int id;//编号
    private String name;//名称
    private String Type;//类型
}

/**
 * 泛型测试类
 *
 * @param <T> 参数1（泛型对象）
 * @param <S> 参数2（继承Pet类的泛型对象）
 */
@Data
public class User<T, S extends Pet> {
    /*带参构造*/
    public User(int id, String name, String Type, List<T> t, List<S> s) {
        this.id = id;
        this.name = name;
        this.Type = Type;
        this.tList = t;
        this.sList = s;
    }

    /*泛型属性*/
    private List<T> tList;//泛型List
    private List<S> sList;//继承Pet类的泛型List

    /*一般属性*/
    private int id;//编号
    private String name;//名称
    private String Type;//类型

    /*重写toString()方法*/
    @Override
    public String toString() {
        String msg = "id为【%s】的【%s】用户【%s】拥有猫猫【%s】和汽车【%s】";
        return String.format(msg, this.id, this.Type, this.name, this.sList.toString(), this.tList.toString());
    }
}

/**
 * 测试类
 */
public class Test {
    public static void main(String args[]) {
        List<Pet> petList = new ArrayList<Pet>();
        petList.add(new Pet(1, "汤圆", "英短"));
        petList.add(new Pet(2, "糯米", "英短"));
        petList.add(new Pet(3, "咖喱", "田园"));

        List<Car> carList = new ArrayList<Car>();
        carList.add(new Car(1, "标志", "小轿车"));
        carList.add(new Car(2, "哈弗", "SUV"));

        User user = new User(1, "ZH", "男性", carList, petList);//第5个参数如果不是一个继承了Pet类的List，则编译会报错
        System.out.println(user.toString());
    }
}