Java设计模式之装饰者模式

//被装饰者的对象接口
public interface Drink {
    public float cost();
    public String desc();
}

//具体的被装饰者
public class Dounai implements Drink{
    @Override
    public float cost() {
        return 3f;
    }
    @Override
    public String  desc() {
        return "纯豆奶";

    }
}

//装饰者的基类
public abstract class Decroator implements Drink  {
    private Drink drink; //要装饰的对象

    public Decroator(Drink drink) {
        this.drink = drink;
    }

    @Override
    public float cost() {
        return drink.cost();
    }

    @Override
    public String desc() {
      return  drink.desc();
    }
}

//具体的装饰者
public class Blackdou extends Decroator {
    public Blackdou(Drink drink) {
        super(drink);
    }

    @Override
    public float cost() {
        return super.cost()+2f;
    }

    @Override
    public String desc() {
        return super.desc()+"+黑豆";
    }
}

//具体的装饰者类
public class SugarDecroator extends Decroator {
    public SugarDecroator(Drink drink) {
        super(drink);
    }
    @Override
    public float cost() {
        return super.cost()+1f;
    }
    @Override
    public String desc() {
        return super.desc()+"+糖";
    }
}

public class Test {
    public static void main(String[] args) {

        Drink drink = new Dounai();
        Blackdou blacktang = new Blackdou(drink);
        SugarDecroator  sugar = new SugarDecroator(blacktang);

        System.out.println("这杯豆浆价格为："+sugar.cost());
        System.out.println("描述为："+sugar.desc());
    }
}

这杯豆浆价格为：6.0
描述为：纯豆奶+黑豆+糖