卡车要装载一批货物，货物有3种商品

卡车要装载一批货物，货物有3种商品：电视、计算机和洗衣机。需要计算出大货车和小货车各自所装载的3中货物的总重量。编写一个Java应用程序，要求有一个ComputeWeight接口，该接口中有一个方法：public double computeWeight(); 有3个实现该接口的类：Television、Computer和WashMachine。这3个类通过实现接口ComputeWeight给出自重。有一个Car类，该类用ComputeWeight接口类型的数组作为成员，那么该数组的元素就可以存放Television对象的引用、Computer对象的引用或WashMachine对象的引用。程序能输出Car对象所装载的货物的总重量

package homework2;
/*
File name:Car.cpp
Author:杨柳
Date:2017/11/6
IDE:eclipse
*/
class Car {
	ComputeWeight[] goods;
	double totalWeight=0;
	Car (ComputeWeight[] goods)
	{
	this.goods=goods;
	}
	public static void main(String[] args) {
		// TODO Auto-generated method stub
		ComputeWeight[] goods=new ComputeWeight[3];
		goods[0]=new Television(345.6); //上转型对象
		goods[1]=new Computer(789.3);
		goods[2]=new WashMachine(576.0);
		Car car=new Car(goods);
		double totalweight;
		totalweight=goods[0].computeWeight()+goods[1].computeWeight()+goods[2].computeWeight();
		System.out.println("所装载的货物的总重量为:"+totalweight);

	}

}
interface ComputeWeight {
	public double computeWeight(); 

}
public class Computer implements ComputeWeight {
	double cweight;
	Computer(double c){
		this.cweight=c;
	}
	public double computeWeight(){
		return cweight;

	}
}
public class Television implements ComputeWeight { //通过实现接口ComputerWeight给出自重
	double tweight;
	Television(double t){
		this.tweight=t;
	}
	public double computeWeight(){
		return tweight;

}
}
public class WashMachine implements ComputeWeight{
	double wweight;
	WashMachine(double w){
		this.wweight=w;
	}
	public double computeWeight(){
		return wweight;

	}

}