题目

一个咖啡店可以提供大杯(JorumCoffee)、中杯(MediumCoffee)、小杯(SmallCoffee)的咖啡(Coffee)，为了满足不同用户的口味，在咖啡中可以添加牛奶(Milk)，或者糖(Sugar)，或者柠檬(Lemon)，提供给用户不同口味的组合，如大杯咖啡加牛奶，中杯咖啡加糖，小杯咖啡加柠檬，小杯咖啡加糖等。

代码

定义口味接口，及咖啡接口

口味

interface Additives{
    public void add();
}

咖啡

interface Coffee{
    public void add(Additives additives);
    public void drink();
}

实现类

口味

class Milk implements Additives{
    @Override
    public void add() {
        System.out.println("牛奶");
    }
}
class Sugar implements Additives{
    @Override
    public void add() {
        System.out.println("糖");
    }
}
class Lemon implements Additives{
    @Override
    public void add() {
        System.out.println("柠檬");
    }
}

咖啡

class smallCoffee implements Coffee{
    private Additives additives;
    @Override
    public void add(Additives additives) {
        this.additives=additives;
    }
    @Override
    public void drink() {
        additives.add();
        System.out.println("小咖啡");
    }
}

class mediumCoffee implements Coffee{
    private Additives additives;
    @Override
    public void add(Additives additives) {
        this.additives=additives;
    }
    @Override
    public void drink() {
        additives.add();
        System.out.println("中咖啡");
    }
}


class bigCoffee implements Coffee{
    private Additives additives;
    @Override
    public void add(Additives additives) {
        this.additives=additives;
    }
    @Override
    public void drink() {
        additives.add();
        System.out.println("大咖啡");
    }
}

UML图