简单泛型

嵌套咯

ROOM  ----》RoomBox

RoomBox

public class RoomBox<T> {private Box<T> box;public Box<T> getBox(){return box;}public void setBox(Box<T> box){this.box = box;}}

Room

public class Room<T> {private T thing;public T getThing(){return thing;}public void setThing(T thing){this.thing = thing;}@Overridepublic String toString(){return "Room[thing=" + thing + "]";}}

测试类

public class RoomBoxTest {public static void main(String[] args){RoomBox<String> roomBox = new RoomBox<>();Box<Integer> box = new Box<>();Box<String> boxString = new Box<>();roomBox.setBox(boxString);// 注意 泛型 类型 必须 一致RoomBox<Box<String>> room = new RoomBox<>();Box<Box<String>> boxBox = new Box<>();room.setBox(boxBox);}}