接口与实现：实验2

接口：

package mypackage;

public interface ComputeWeight {
	public abstract double computeweight();
}

接口实现：

package mypackage;

public class Computer implements ComputeWeight {

	@Override
	public double computeweight() {
		// TODO 自动生成的方法存根
		return 3.0;
	}

}

package mypackage;

public class Television implements ComputeWeight {

	@Override
	public double computeweight() {
		// TODO 自动生成的方法存根
		return 3.5;
	}

}

package mypackage;

public class WashMachine implements ComputeWeight {

	@Override
	public double computeweight() {
		// TODO 自动生成的方法存根
		return 10.5;
	}

}

类：

package mypackage;

public class Truck {
	ComputeWeight []goods;
	public Truck(ComputeWeight []goods){
		this.goods=goods;
	}
	public void setGoods(ComputeWeight []goods ){
		this.goods=goods;
	}
	public double getTotalWeight() {
		double totalWeights=0;
		for(int i=0; i<goods.length; i++) {
			totalWeights += goods[i].computeweight();
		}
		return totalWeights;
	}
}

主类：

package Main;
import mypackage.*;
public class CheckCarWeight {

	public static void main(String[] args) {
		// TODO 自动生成的方法存根
		ComputeWeight [] goods =new ComputeWeight[650];
		for(int i=0; i<goods.length; i++) {
			if(i%3==0) goods[i]=new Television();
			else if(i%3==1) goods[i]=new Computer();
			else goods[i]=new WashMachine();
		}
		Truck truck=new Truck(goods);
		System.out.println("货物重量："+
		                   truck.getTotalWeight());
		goods=new ComputeWeight[68];
		for(int i=0; i<goods.length; i++) {
			if(i%2==0) goods[i]=new Television();
			else goods[i]= new WashMachine();
		}
		truck.setGoods(goods);
		System.out.println("货物重量："+
		                   truck.getTotalWeight());
	}

}