javaweb-這種裝修設計模式怎麼寫

這種裝修設計模式怎麼寫

就像這樣的

這種的設計模式，先寫什麼後寫什麼，
求大神幫我羅列書詳細步驟圖，我是個新手，
所以比較蒙，感謝各位大神了，或者有類似的代碼也可以。
------------十分感謝你們的幫助

最佳回答：

public abstract class Home
{
public string description = "空房子";
public abstract string getDescription();

    public Double Area;
    public abstract Double getArea();
}

//房子
public class House : Home
{
    public House()
    {
        description = "MyHouse:";
    }

    public override string getDescription()
    {
        return description;
    }

    public override Double getArea()
    {
        return 0.0;
    }
}

//主臥
public class MainCell : Home 
{
    Home home;

    public MainCell(Home home,Double area)
    {
        this.home = home;
        this.Area = area;
    }

    public override string getDescription()
    {
        return this.home.getDescription() + " MainCell";
    }

    public override Double getArea()
    {
        return this.Area + home.getArea(); 
    }
}

//陽台
public class Balcony : Home
{
    Home home;

    public Balcony(Home home, Double area)
    {
        this.home = home;
        this.Area = area;
    }

    public override string getDescription()
    {
        return this.home.getDescription() + " Balcony";
    }

    public override Double getArea()
    {
        return this.Area + home.getArea();
    }
}