java - 设置聚合特征

Question

我的问题是，您可以在房间类的实例化时设置房间参数，但是如何设置房间类的聚合特征的属性，例如墙壁属性和 window 属性？因为我不想使用 setter ？还有别的办法吗？

因为我可以实例化房间，然后我必须单独添加墙壁和 window 的实例？因为我可以实例化 3 个房间，所以每个房间都有不同的 window 和墙壁尺寸？

  ROOM CLASS < AGGREGATED WALL ARRAY LIST < AGREGGATED WINDOWS ARRAY LIST

谢谢

Answer 1

<罢工> 是的， builder 。喜欢

<罢工>

public class Room {

    private List<Window> windows = new ArrayList<Window>();
    private List<Wall> walls = new ArrayList<Wall>();
    private List<Door> doors = new ArrayList<Door>();

    public Room(int windows, int walls, int doors){
        for(int i=0; i < windows; i++)
            windows.add(new Window());
         //similarly for walls and Doors :)
    }

     //getters
}

<罢工> 更新来自评论:OP希望避免setter，结果发现Windows可能是不同类型的。看来这是某种对作文能力的考验，has-a东西。

我猜你需要这个。 弄清楚!

NOTE: I have written this in this editor, for conceptual understanding purpose, code may not compile

//you see rooms have walls, and many. So constructor takes List of 
//windows and doors in each wall. So, a List of walls that has List 
// (mixed bag) of windows and doors in each wall -- some may have no 
//window/door, then 2nd list will be empty.
public class Room {

    List<Wall> _walls = new ArrayList<Wall>();

    public Room(List<List<Openable>> walls){
        for(List<Openable> windowsOrDoors : walls){
            this._walls.add(new Wall(windowsOrDoors));
        }
    }
}

//wall can have many doors and/or windows. We pass out mixed 
// bag list here, constructor will figure out how to keep 
//them in separate lists
public class Wall {

    List<Door> doors = new ArrayList<Door>();
    List<Window> windows = new ArrayList<Window>();

    public Wall(List<Openable> openables){
        for(Openable windowsOrDoor : openables){
            if(windowsOrDoor instanceOf Window)
                this.windows.add(windowsOrDoors);
            else
                this.doors.add(windowsOrDoors);
        }
    }
}

//Window class, simple class -- it is of type Openable
public class Window implements Openable{
    public Window(int w, int h){
        //do something
    }
}

//Door class, simple class -- it is of type Openable
public class Door implements Openable{
    public Door(int w, int h){
        //do something
    }
}

//Openable -- a common interface to Window and Door, you can use 
//abstract class here and have getHeight, getWidth and other common 
//methods. This just for the purpose that if you wanted to add another 
//Window/Door class like `ArchedDoor` which has a `radius` as well, 
//you will just write a `ArchedDoor implements Openable` and pass into 
//the Room/Wall constructor. Nothing will break. 
public interface Openable{}