Java租车系统（新手）

以前只学过C，刚看完Java两季，第一次写这么长程序，希望能和大家互相交流一下。
创建父类Car

public class Car {
       String name;
       int num;
       double rentPrice;
    public String getName() {
        return name;
    }
    public double getRentPrice() {
        return rentPrice;
    }        
}

创建支持载货的接口ICargoCapacity

public interface ICargoCapacity {
    public double CargoCapacity();
}

创建支持载人的接口IPeopleCapacity

public interface IPeopleCapacity {
         public int PeopleCapacity();
}

创建子类Audi

public class Audi extends Car implements IPeopleCapacity {
    int num=1;
    String name="奥迪A4";
    double rentPrice=500;
    public String getName() {
        return name;
    }
    public double getRentPrice() {
        return rentPrice;
    }
    @Override
    public int PeopleCapacity() {
        // TODO Auto-generated method stub
        int peopleCapacity=4;
        return peopleCapacity;
    }
    public String toString(){
        return num+".   "+name+"   "+rentPrice+"/天     载人:"+this.PeopleCapacity()+"人";
    }
}

创建子类Mazda

public class Mazda extends Car implements IPeopleCapacity {
    int num=2;
    String name="马自达6";
    double rentPrice=400;   
    public String getName() {
        return name;
    }
    public double getRentPrice() {
        return rentPrice;
    }
    @Override
    public int PeopleCapacity() {
        // TODO Auto-generated method stub
        int peopleCapacity=4;
        return peopleCapacity;
    }
    public String toString(){
        return num+".   "+name+"  "+rentPrice+"/天     载人:"+this.PeopleCapacity()+"人";
    }
}

创建子类Pika

public class Pika extends Car implements IPeopleCapacity, ICargoCapacity {
    int num=3;
    String name="皮卡雪6";
    double rentPrice=450; 
    public String getName() {
        return name;
    }
    public double getRentPrice() {
        return rentPrice;
    }
    @Override
    public double CargoCapacity() {
        // TODO Auto-generated method stub
        double cargoCapacity=2;
        return cargoCapacity;
    }
    @Override
    public int PeopleCapacity() {
        // TODO Auto-generated method stub
        int peopleCapacity=4;
        return peopleCapacity;
    }
    public String toString(){
        return num+".   "+name+"  "+rentPrice+"/天     载人:"+this.PeopleCapacity()+"人"+"载货:"+this.CargoCapacity()+"吨";
    }
}

创建子类Jinlong

public class Jinlong extends Car implements IPeopleCapacity {
    int num=4;
    String name="金龙";
    double rentPrice=800;   
    public String getName() {
        return name;
    }
    public double getRentPrice() {
        return rentPrice;
    }
    @Override
    public int PeopleCapacity() {
        // TODO Auto-generated method stub
        int peopleCapacity=20;
        return peopleCapacity;
    }
    public String toString(){
        return num+".   "+name+"             "+rentPrice+"/天     载人:"+this.PeopleCapacity()+"人";
    }
}

创建子类Songhuajiang

public class Songhuajiang extends Car implements ICargoCapacity {
    int num=5;
    String name="松花江";
    double rentPrice=400;    
    public String getName() {
        return name;
    }
    public double getRentPrice() {
        return rentPrice;
    }
    @Override
    public double CargoCapacity() {
        // TODO Auto-generated method stub
        int cargoCapacity=4;
        return cargoCapacity;
    }
    public String toString(){
        return num+".   "+name+"        "+rentPrice+"/天     载货:"+this.CargoCapacity()+"吨";
    }
}

创建子类Yiweike

public class Yiweike extends Car implements ICargoCapacity {
    int num=6;
    String name="依维柯";
    double rentPrice=1000;
    public String getName() {
        return name;
    }
    public double getRentPrice() {
        return rentPrice;
    }
    @Override
    public double CargoCapacity() {
        // TODO Auto-generated method stub
        double cargoCapacity=20;
        return cargoCapacity;
    }
    public String toString(){
        return num+".   "+name+"        "+rentPrice+"/天   载货:"+this.CargoCapacity()+"吨";
    }
}

主程序

import java.util.Scanner;
public class Initial {
    //打印租车列表
    public static void Print(Car car[]){
        System.out.println("您可租车的类型及价目表:\n序号  汽车名称    租金           容量");
        for(int i=0;i<car.length;i++){
            System.out.println(car[i].toString());
        }
        System.out.println("请输入您要租汽车的数量:");
    }
    public static void main(String[] args) {        
        System.out.println("欢迎使用答答租车系统：\n您是否要租车：1是 0否");
        Scanner input=new Scanner(System.in);
        if(input.nextInt()==1){
            Car car[]={new Audi(),new Mazda(),new Pika(),new Jinlong(),new Songhuajiang(),new Yiweike()};
            Print(car);
            getCar(car);
            }       
        else{
            input.close();
            System.out.println("退出系统");
        }                   
    }
    //统计所选车的信息
    public static void getCar(Car car[]){
        Scanner input=new Scanner(System.in);
        int totalPeople=0;
        double totalCargo=0,totalPrice=0;
        String peopleCar=" ",cargoCar=" ";
        for(int i=1,carNums=input.nextInt();i<=carNums;i++){
            System.out.println("请输入第"+i+"辆车的序号:");
            int Num=input.nextInt();
               //通过接口判断该车能否载人
               if(car[Num-1] instanceof IPeopleCapacity){
                   totalPeople+=((IPeopleCapacity)car[Num-1]).PeopleCapacity();
                   peopleCar=peopleCar+car[Num-1].getName()+"  ";
               }
               //通过接口判断该车能否载货
               if(car[Num-1] instanceof ICargoCapacity){
                   totalCargo+=((ICargoCapacity)car[Num-1]).CargoCapacity();
                   cargoCar=cargoCar+car[Num-1].getName()+"  ";                    
               }
               totalPrice+=car[Num-1].getRentPrice();
            }
        System.out.println("请输入租车天数:");
        totalPrice*=input.nextInt();
        input.close();
        System.out.println("您的账单:\n***可载人的车有:\n"+peopleCar+"\t共载人:"+totalPeople+"人");
        System.out.println("***载货的车有:\n"+cargoCar+"\t共载货:"+totalCargo+"吨");
        System.out.println("***租车总价格:"+totalPrice+"元");
    }
}