都实现

好的，下面是Truck类的实现代码：

public class Truck {
    private ComputeWeight[] goods;

    public Truck(ComputeWeight[] goods) {
        this.goods = goods;
    }

    public double getTotalWeight() {
        double totalWeight = 0;
        for (ComputeWeight good : goods) {
            totalWeight += good.computeWeight();
        }
        return totalWeight;
    }
}

在Truck类中，我们存储了一个ComputeWeight类型的数组goods，表示该货车上的所有家电。getTotalWeight()方法就是遍历数组goods，计算所有货物的重量之和。