java - JAVA中的装饰模式问题

Question

我有 - Worker 界面。 每个 worker 都有能量。

public interface Worker {
    int work();
    double getEnergy();
}

和 - JuniorWorker 类，实现 Worker 接口(interface)。 初级 worker 有100能量。

public class juniorWorker implements Worker {
    public int work() {
        return (int) getEnergy();
    }
    public double getEnergy() {
        return 100;
    }
}

并且还有 - effectiveWork、powerWork 类，实现 Worker 接口(interface)。 高效工作将减少20%的能源。 powerWork 将使能量提高 10%。

public class efficientWork implements Worker {
    private Worker worker;
    public efficientWork(Worker w) {
        this.worker=w;
}
    public int work() {
        return (int) (worker.getEnergy()*getEnergy());
    }
    public double getEnergy() {
        return 0.8;
    }
}
public class PowerWork implements Worker {
    private Worker worker;
    public PowerWork(Worker w) {
        this.worker=w;
}
    public int work() {
        return  (int) (worker.getEnergy()*getEnergy());
    }
    public double getEnergy() {
        return 1.1;
    }
}

实际上，我正在尝试 int work() 来总结每个 worker 将花费的总能量。 例如我的Demo类:

public class Demo {
    public static void main(String[] args) {
        Worker j= new efficientWork(new juniorWorker());
        System.out.println(j.work());
    }
}

此案例正在运行 - 系统将打印80。

但是这个例子，总是打印 0 :

public class Demo {
    public static void main(String[] args) {
        Worker j= new efficientWork(new PowerWork(new juniorWorker()));
        System.out.println(j.work());
    }
}

帮忙？我期待得到88! (110*0.8)

Answer 1

您应该调用 work()不是getEnergy()方法在装饰器内保存的封闭工作对象上 work()方法。

// decorator's work method
public int work() {
    // return (int) (worker.getEnergy() * getEnergy()); // NO!
    return (int) (worker.work() * getEnergy());    // YES!
}