直觉与设计原则

Question

我有这样的类层次结构Beverage -> Coffee-> Latte.哪里Beverage是abstract超被延长Coffee.Coffee然后类增加了一些行为,但也是abstract.Latte扩展Coffee类,是一个具体的类.我已经使用继承来添加行为.并且继承确实有缺点,如超类方法的可见性,使代码易碎,代码紧密耦合.因此,编程原则Composition应该优先考虑Inheritance.但在这种情况下inheritance感觉如此自然Latte,Coffee并且Coffee是一种类型的Beverage使用composition添加行为感觉错误,尽管它的好处.所以这里的问题是 应该直觉覆盖设计原则吗？

饮料:

public abstract class Beverage {

    private final String name;
    private final double price;

    Beverage(String name, double price){
        this.name = name;
        this.price = price;
    }

    public String getName() {
        return name;
    }
    public double getPrice() {
        return price;
    }

    public abstract void make();
    }

咖啡:

public abstract class Coffee extends Beverage {

    public Coffee(String name, double price) {
        super(name, price);
    }


    public final void make(){
        grindBeans();
        takeShot();
        frothMilk();
        addCondiments();
    }

    public void grindBeans(){
        System.out.println("Grinding Beans...");
    }

    public void takeShot(){
        System.out.println("Taking Shot....");
    }

    public abstract void frothMilk();
    public abstract void addCondiments();


}

拿铁:

public class Latte extends Coffee {

    public Latte() {
        super("Latte", 4.0);
    }

    @Override
    public void frothMilk() {
        System.out.println("Frothing milk to create micro foam");

    }

    @Override
    public void addCondiments() {
        // TODO Auto-generated method stub

    }

}

编辑:添加Sugar到现有结构.仅显示新代码.

public abstract class Beverage {

private Sugar sugar;

public Sugar getSugar() {
    return sugar;
}

public void setSugar(Sugar sugar) {
    this.sugar = sugar;
}

}

咖啡:

public abstract class Coffee extends Beverage {

public final void make(){
    grindBeans();
    takeShot();
    frothMilk();
    addSugar();
    addCondiments();
}

public void addSugar(){
    Sugar sugar = super.getSugar();
    if(!(sugar instanceof NoSugar)){
        System.out.println("adding " + sugar.getTeaspoon() + " teaspoon sugar");
    }
}

Answer 1

虽然组合比继承有许多好处,但是在感觉自然的情况下(即在真正的is-a关系中)使用继承并没有错.如果它很自然,请继续使用它.