1. 父类Car（属性name，price）

2. 子类Trunk（独有属性：载货量）

3. 子类Bus（独有属性：载客量）

4. 子类Pickup（独有属性：载货量，载客量）

5. CarRentTest（测试类）
   

package CarRent;

public class Car {

    private String carName;    
    private int carPrice;  
      
    public Car(String name, int price) {
        carName = name;
        carPrice = price;
    }
    
    public String getCarName() {
        return carName;
    }
    
    public int getCarPrice() {
        return carPrice;
    }
    
    public void setCarName(String carName) {
        this.carName = carName;    
    }
    
    public void setCarPrice(int carPrice) {
        this.carPrice = carPrice;
    }
}

package CarRent;

/* 货车，只能载货 */

public class Truck extends Car {

    private int boatload; // 载货量
    
    public Truck(String name, int price, int boatload) {
        super(name, price);
        this.boatload = boatload;
    }
    
    public int getBoatload() {
        return boatload;
    }
       
    public void setBoatload(int boatload) {
        this.boatload = boatload;
    }
    
}

package CarRent;

/* 客车，只能载人 */

public class Bus extends Car {

    private int busload; // 载客量
    
    public Bus(String name, int price, int busload) {        
        super(name, price);        
        this.busload = busload;    
    }
    
    public int getBusload() {        
        return busload;    
    }    
    
    public void setBusload(int busload) {        
        this.busload = busload;    
    }

}

package CarRent;

/* 皮卡，既可以载货也可以载人 */

public class Pickup extends Car {        
    
    private int boatload; // 载货量    
    private int busload; // 载客量    

    public Pickup(String name, int price, int boatload, int busload) {        
        super(name, price);        
        this.boatload = boatload;        
        this.busload = busload;
    }    
    
    public int getBoatload() {        
        return boatload;    
    }    
    
    public int getBusload() {        
        return busload;    
    }    
    
    public void setBoatload(int boatload) {        
        this.boatload = boatload;    
    }    
    
    public void setBusload(int busload) {        
        this.busload = busload;    
    }
    
}

package CarRent;

import java.util.Scanner;
import java.util.List;
import java.util.ArrayList;

public class CarRentTest {    

    public static void main(String[] args) {        
        
        Car availableCars[] = new Car[] {            
            new Bus("奥迪A4", 500, 4),            
            new Bus("马自达6", 400, 4),            
            new Pickup("皮卡雪6", 450, 2, 4),            
            new Bus("金龙", 800, 20),            
            new Truck("松花江", 400, 4),            
            new Truck("依维柯", 1000, 20)        
        };        
        Scanner input = new Scanner(System.in);        
        System.out.println("欢迎使用答答租车系统：");        
        System.out.print("您是否要租车：1 是；0 否 >>> ");        
        int rentOrNot = input.nextInt();        
        while (rentOrNot != 0 && rentOrNot != 1) {
            System.out.print("无效输入。请重新输入：1 是；0 否 >>> ");            
            rentOrNot = input.nextInt();            
            if (rentOrNot == 0) {
                System.out.println("再见！欢迎下次使用！");
                System.exit(0);
            } else if (rentOrNot == 1) {
                break;            
            } else {
                continue;
            }
        }
        
        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\t容量");        
        for (int i = 0; i < availableCars.length; i++) {            
            Car car = availableCars[i];            
            System.out.print((i+1)+".\t");            
            System.out.print(car.getCarName()+"\t\t");            
            System.out.print(car.getCarPrice()+"元/天\t");            
            if (availableCars[i] instanceof Truck) {                
                System.out.print("载货："+((Truck)car).getBoatload()+"吨\n");            
            } else if (availableCars[i] instanceof Bus) {                
                System.out.print("载人："+((Bus)car).getBusload()+"人\n");            
            } else if (availableCars[i] instanceof Pickup) {                
                System.out.print("载人："+((Pickup)car).getBusload()+"人 载货："+((Pickup)car).getBoatload()+"吨\n");
            }
        }
        
        System.out.print("请输入您要租汽车的数量（0 ~ "+availableCars.length+"）：>>> ");        
        int rentNumber = input.nextInt();        
        while (rentNumber < 0 || rentNumber > availableCars.length) {
            System.out.print("无效输入。请重新输入（0 ~ "+availableCars.length+"）：>>> ");
            rentNumber = input.nextInt();
        }        
        List<Integer> carsAlreadyPicked = new ArrayList<>();
        for (int i = 1; i <= rentNumber; i++) {
            System.out.print("请输入第"+i+"辆车的序号：>>> ");            
            int carID = input.nextInt();            
            while (carsAlreadyPicked.contains(carID) || carID < 1 || carID > availableCars.length) {                
                if (carID < 1 || carID > availableCars.length) {                    
                    System.out.print("无效输入。请重新输入：>>> ");               
                } else {                    
                    System.out.print("该车已选择。请重新选择：>>> ");               
                }                
                carID = input.nextInt();            
            }            
            carsAlreadyPicked.add(carID);        
         }        
         
         System.out.print("请输入租车天数（> 0）：>>> ");        
         int rentDay = input.nextInt();        
         while (rentDay <= 0) {            
             System.out.print("无效输入。请重新输入：>>> ");            
             rentDay = input.nextInt();       
         }        
         
         int totalExpense = 0, totalBusLoad = 0, totalBoatLoad = 0;        
         for (int id : carsAlreadyPicked) {            
             totalExpense += availableCars[id-1].getCarPrice();        
         }        
         totalExpense *= rentDay;        
         System.out.println("您的账单：");        
         System.out.println("***可载人的车有：");        
         for (int id : carsAlreadyPicked) {            
             Car car = availableCars[id-1];            
             if (availableCars[id-1] instanceof Bus || availableCars[id-1] instanceof Pickup) {                
                 System.out.print(car.getCarName()+"\t");                
                 totalBusLoad += (availableCars[id-1] instanceof Bus) ? ((Bus)car).getBusload() : ((Pickup)car).getBusload();            
             }        
         }        
         System.out.print("共载人："+totalBusLoad+"人\n");        
         System.out.println("***载货的车有：");        
         for (int id : carsAlreadyPicked) {            
             Car car = availableCars[id-1];            
             if (availableCars[id-1] instanceof Truck || availableCars[id-1] instanceof Pickup) {                
                 System.out.print(car.getCarName()+"\t");                
                 totalBoatLoad += (availableCars[id-1] instanceof Truck) ? ((Truck)car).getBoatload() : ((Pickup)car).getBoatload();            
             }        
         }        
         System.out.print("共载货："+(double)totalBoatLoad+"吨\n");        
         System.out.print("***租车总价格：");        
         System.out.print(totalExpense+"元\n"); 
                
         input.close();        
         System.out.println("再见！欢迎下次使用！");    
         
    }
}