车的父类

package com.imooc;

//所有车的父类
public class Car {
    String name;    //车名
    int price;    //租金
    int busload;  //载人的数量
    float cargo;    //载客量
    int id;      //序列号

    public void Car(int id,String name,float cargo,int price) {
        this.id=id;
        this.name=name;
        this.cargo=cargo;
        this.price=price;
    }

    public int getPrice() {
        return price;
    }

    public void setPrice(int price) {
        this.price=price;
    }

}

货车接口

package com.imooc;

//货车接口
public interface cargo {
    void trnsport();

}

客车接口

package com.imooc;

//客车接口
public interface passenger {
    void carry();

}

客车类

package com.imooc;

//客车类
public class Pessengers extends Car implements passenger {
    public Pessengers(int id,String name,int busload,float price) {
        System.out.println(id+","+name+busload+"人"+" "+price+"元、天      载人");
    }

    @Override
    public void carry() {
        // TODO Auto-generated method stub

    }

    @Override
    public int getPrice() {
        // TODO Auto-generated method stub
        return super.getPrice();
    }

    @Override
    public void setPrice(int price) {
        // TODO Auto-generated method stub
        super.setPrice(price);
    }

}

客车类

package com.imooc;

//客车类
public class Pessengers extends Car implements passenger {
    public Pessengers(int id,String name,int busload,float price) {
        System.out.println(id+","+name+busload+"人"+" "+price+"元、天      载人");
    }

    @Override
    public void carry() {
        // TODO Auto-generated method stub

    }

    @Override
    public int getPrice() {
        // TODO Auto-generated method stub
        return super.getPrice();
    }

    @Override
    public void setPrice(int price) {
        // TODO Auto-generated method stub
        super.setPrice(price);
    }

}

皮卡车类

package com.imooc;

//皮卡车类
public class pickUp extends Car implements passenger, cargo {

    public pickUp(int id,String name,int busload,float cargo,float price) {
        System.out.println(id+","+name+ " "+busload+"人 ，载货  "+cargo+"吨"+"  "+price);
    }

    @Override
    public void trnsport() {
        // TODO Auto-generated method stub

    }

    @Override
    public int getPrice() {
        // TODO Auto-generated method stub
        return super.getPrice();
    }

    @Override
    public void setPrice(int price) {
        // TODO Auto-generated method stub
        super.setPrice(price);
    }

    @Override
    public void carry() {
        // TODO Auto-generated method stub

    }

}

货车类

package com.imooc;

//货车类
public class Track extends Car implements cargo {
    public Track(int id,String name,float cargo,float price) {
        System.out.println(id+","+name+" "+cargo+"吨"+" "+price);
    }

    @Override
    public void trnsport() {
        // TODO Auto-generated method stub

    }

    @Override
    public int getPrice() {
        // TODO Auto-generated method stub
        return super.getPrice();
    }

    @Override
    public void setPrice(int price) {
        // TODO Auto-generated method stub
        super.setPrice(price);
    }

}

租车系统

package com.imooc;

import java.util.Scanner;

public class rentSystem {
    Scanner sc=new Scanner(System.in);
    private Car[] car=new Car[]{
        new Pessengers(1,"奥迪A4",4,500),
        new Pessengers(2,"马自达",4,450),
        new pickUp(3,"皮卡雪",4,2,200),
        new Pessengers(4,"金龙",4,800),
        new Track(5,"松花江",4,400),
        new Track(6,"依维柯",20,1000)
    };

    public int sum=0;
    int choose (int num) {
        int n=0;
        for(int i = 0 ; i < num ; i ++)
        {
            System.out.println("请输入第"+(i + 1)+"辆车的序号：  ");
            int x = sc.nextInt()-1;

            switch(x)
            {
            case 0:
                n = car[0].getPrice();
                break;
            case 1:
                n = car[1].getPrice();
                break;
            case 2:
                n = car[2].getPrice();
                break;
            case 3:
                n = car[3].getPrice();
                break;
            case 4:
                n = car[4].getPrice();
                break;
            case 5:
                n = car[5].getPrice();
                break;
            }
            sum+=n;
        }
        return sum;
    }

}

测试类

package com.imooc;

import java.util.Scanner;

//测试类
public class Test {

    public static void main(String[] args) {
        int total;
        int num;
        int sum;
        Scanner sc = new Scanner(System.in);

        System.out.println("欢迎使用DD租车");
        System.out.println("您是否要租车？1：是  0：否");
        int answer = sc.nextInt();
        if ( answer == 1) {
            System.out.println("您可租车的类型及其价目表");
            System.out.println("序号       汽车名称        租金                容量");
            rentSystem rt = new rentSystem();

            System.out.println("请输入您要租的汽车数量");
            num = sc.nextInt();
            sum = rt.choose(num);

            System.out.println("请输入您要租的天数");
            int day = sc.nextInt();
            total = day*sum;
            System.out.println("最后要租用的费用是：" + total);

            answer ++;

        }
        else
        {
            System.out.println("这家伙很懒啥也没看。");
        }

    }

}

小白参考大神的作品跟着写的~