新手上路，请多多关照！

测试类
package com.imooc;

import java.util.Scanner;

public class Test {

/**
 * 测试类
 * @param args
 */
public static void main(String[] args) {

    int totalPeople=0;//总人数
    int totalWeight=0;//总载货量
    int totalPrice=0;//总价格
    StringBuffer s1=new StringBuffer();//保存载客车辆的名称
    StringBuffer s2=new StringBuffer();//保存载货车辆的名称
    Car[] cars={new PassengerCar(1, "奥迪A6", 500, 4)
    ,new PassengerCar(2, "比亚迪G6", 450, 5)
    ,new CargoCar(3, "东风C2", 600, 4)
    ,new CargoCar(4,"东风V8",700,8)
    ,new PickupCar(5, "皮卡雪V6", 900, 4, 2)};

    Scanner scanner=new Scanner(System.in);
    System.out.println("欢迎使用答答租车系统:"+"\n"+"您是否要租车:1是  0否");
    int isNo=scanner.nextInt();
    if(isNo==0){
        System.exit(0);
    }else{
        System.out.println("您可租车的类型及其价目表:");
        System.out.println("序号"+"\t"+"汽车名称"+"\t"+"租金"+"\t"+"容量");
        for(int i=0;i<cars.length;i++){
            System.out.println(cars[i]);
        }
        System.out.println("请输入您要租汽车的数量:");
        int amount=scanner.nextInt();
        if(amount>cars.length){
            System.out.println("您输入的数量大于车库中车辆的数量，请重新输入！");
        }else{
            for(int j=0;j<amount;j++){
                System.out.println("请输入第"+(j+1)+"辆车的序号:");
                int No=scanner.nextInt();
                if(cars[No-1] instanceof PassengerCar || cars[No-1] instanceof PickupCar){
                    s1.append(cars[No-1].vehicleName+" ");
                }
                if(cars[No-1] instanceof CargoCar || cars[No-1] instanceof PickupCar){
                    s2.append(cars[No-1].vehicleName+" ");
                }
                totalPeople+=cars[No-1].number;
                totalWeight+=cars[No-1].weight;
                totalPrice+=cars[No-1].price;
            }
            System.out.println("请输入租车天数:");
            int days=scanner.nextInt();
            System.out.println("您的账单:");
            System.out.println("***可载人的车有:");
            System.out.println(s1.toString()+"\t"+"共载人:"+totalPeople+"人");
            System.out.println("***载货的车有:");
            System.out.println(s2.toString()+"\t"+"共载货:"+totalWeight+"吨");
            totalPrice=totalPrice*days;
            System.out.println("***租车总价格:"+totalPrice);
        }
    }
}

}