这是我在学完java入门第二季之后编写的答答租车系统源码，相较于老师的给的流程，增加了用户输入错误字符时的提示。
　　主函数CarRentingSystem.java：
import java.util.Scanner;/** * Time 16-5-19 * * 汽车租赁系统 */public class CarRentingSystem { public static void main(String args[]){ while (true) { System.out.println("请问您是要租车吗？（是/不是）"); Scanner scanner = new Scanner(System.in); String input = scanner.next(); if(input.equals("是")){ Car[] cars = {new CarPeople("奥迪A4",400,4),new CarPeople("马自达",400,4),new CarAll("皮卡6",450,4,20), new CarPeople("金龙",800,20), new CarGoods("松花江",400,4),new CarGoods("依维柯",1000,20)}; System.out.println("以下是您可以租的车："); System.out.println("序号 品牌 价格 载人/货量"); for(int i = 0;i < cars.length;i++){ System.out.printf("%-3d %-6s% 6d %3d个人，%d吨货\n",i + 1,cars[i].getName(),cars[i].getMoney(),cars[i].getPeople(),cars[i].getGoods()); } System.out.println("请输入您要租的数量："); int number = scanner.nextInt(); Car[] chooseCars = new Car[number]; Car[] chooseCarsPeople = new Car[number]; int CCPNum = 0;//选择的载人汽车的数目 Car[] chooseCarsGoods = new Car[number]; int CCGNum = 0;//选择的载货汽车的数目 //定义总共的钱数，载客量，载货量 int money = 0; int people = 0; int goods = 0; for(int i = 0,j = 1;i < number;i++,j++){ System.out.println("请输入第" + j + "辆车的序号："); int carNum = scanner.nextInt() - 1; try { chooseCars[i] = cars[carNum]; money += chooseCars[i].getMoney(); people += chooseCars[i].getPeople(); goods += chooseCars[i].getGoods(); if(chooseCars[i].getPeople() != 0){ chooseCarsPeople[CCPNum] = chooseCars[i]; CCPNum++; } if(chooseCars[i].getGoods() != 0){ chooseCarsGoods[CCGNum] = chooseCars[i]; CCGNum++; } } catch (Exception e) { System.out.println("请输入1~6的序号！\n"); i--; j--; } } System.out.println("请输入您要租的天数："); int dayNum = scanner.nextInt(); System.out.printf("您的总费用：%d元\n您总共租了%d辆车，租赁%d天\n",money*dayNum,number,dayNum); System.out.println("其中，载人的车有" + CCPNum + "辆"); try { for(Car CarsPeople:chooseCarsPeople){ System.out.println(CarsPeople.getName()); } } catch (Exception e) { } System.out.printf("总载客量：%d人\n",people*dayNum); System.out.println("载货的车有" + CCGNum + "辆"); try { for(Car CarsGoods:chooseCarsGoods){ System.out.println(CarsGoods.getName()); } } catch (Exception e) { } System.out.printf("总载货量：%d吨\n",goods*dayNum); break; }else if(input.equals("不是")){ break; }else { System.out.println("请输入正确的选项！\n"); } } System.out.println("感谢您的光临，欢迎下次再来！"); }}　　所有类型汽车的父类Car.java
public class Car { String name; int money; int people; int goods; public String getName() { return name; } public int getMoney() { return money; } public int getPeople() { return people; } public int getGoods() { return goods; }}　　Car 的子类，载人汽车CarPeople.java
public class CarPeople extends Car{ String name; int money; int people; public CarPeople(String name,int money,int people){ this.name = name; this.money = money; this.people = people; } @Override public String toString() { return this.name + "" + this.money + this.people; } public String getName() { return name; } public int getMoney() { return money; } public int getPeople() { return people; }}　　Car 的子类，载货汽车CarGoods.java
public class CarGoods extends Car{ String name; int money; int goods; public CarGoods(String name,int money,int goods){ this.name = name; this.money = money; this.goods = goods; } @Override public String toString() { return this.name + this.money + this.goods; } public String getName() { return name; } public int getMoney() { return money; } public int getGoods() { return goods; }}　　Car 的子类，载人/货汽车CarAll.java
public class CarAll extends Car{ String name; int money; int people; int goods; public CarAll(String name,int money,int people,int goods){ this.name = name; this.money = money; this.people = people; this.goods = goods; } @Override public String toString() { return this.name + this.money + this.people + this.goods; } public String getName() { return name; } public int getMoney() { return money; } public int getPeople() { return people; } public int getGoods() { return goods; }}　　实现结果：
请问您是要租车吗？（是/不是）输入非法字符的情况：请输入正确的选项！请问您是要租车吗？（是/不是）是以下是您可以租的车：序号 品牌 价格 载人/货量1 奥迪A4 400 4个人，0吨货2 马自达 400 4个人，0吨货3 皮卡6 450 4个人，20吨货4 金龙 800 20个人，0吨货5 松花江 400 0个人，4吨货6 依维柯 1000 0个人，20吨货请输入您要租的数量：6请输入第1辆车的序号（1~6）：1请输入第2辆车的序号（1~6）：2请输入第3辆车的序号（1~6）：3请输入第4辆车的序号（1~6）：4请输入第5辆车的序号（1~6）：5请输入第6辆车的序号（1~6）：6请输入您要租的天数：1您的总费用：3450元您总共租了6辆车，租赁1天其中，载人的车有4辆奥迪A4马自达皮卡6金龙总载客量：32人载货的车有3辆皮卡6松花江依维柯总载货量：44吨感谢您的光临，欢迎下次再来！Process finished with exit code 0