JAVA入门第二季项目答答租车系统，功能齐全 修改后已解决所有问题

//父类
package didi;

public class Didi {

    public String name;
    public double rentm;
    public int take;
    public int ton;
    public int rentsum;

    public int getRentsum() {
        return rentsum;
    }

    public void setRentsum(int rentsum) {
        this.rentsum = rentsum;
    }
    public void Didi(String name,double rentm,int take){

    }
    public String getName() {
        return name;
    }

    public void setName(String name) {
        this.name = name;
    }

    public double getRentm() {
        return rentm;
    }

    public void setRentm(double rentm) {
        this.rentm = rentm;
    }

    public int getTake() {
        return take;
    }

    public void setTake(int take) {
        this.take = take;
    }
    public int getTon() {
        return ton;
    }
    public void setTon(int ton) {
        this.ton = ton;
    }

}

//货车类

package didi;

public class CurrentCar extends Didi {

    public String name;
    public double rentm;
    public int ton;
    public int rentsum;

    public int getRentsum() {
        return rentsum;
    }

    public void setRentsum(int rentsum) {
        this.rentsum = rentsum;
    }
    public  CurrentCar(String name,double rentm,int ton){
        this.name=name;
        this.rentm=rentm;
        this.ton=ton;
    }
    public String getName() {
        return name;
    }

    public void setName(String name) {
        this.name = name;
    }

    public double getRentm() {
        return rentm;
    }

    public void setRentm(double rentm) {
        this.rentm = rentm;
    }

    public int getTon() {
        return ton;
    }
    public void setTon(int ton) {
        this.ton = ton;
    }
}

//载人车类
package didi;

public class PassengerCar extends Didi {
    public String name;
    public double rentm;
    public int take;
    public int rentsum;

    public int getRentsum() {
        return rentsum;
    }

    public void setRentsum(int rentsum) {
        this.rentsum = rentsum;
    }

    public PassengerCar(String name,double rentm,int take){

        this.name=name;
        this.rentm=rentm;
        this.take=take;
    }

    public String getName() {
        return name;
    }

    public void setName(String name) {
        this.name = name;
    }

    public double getRentm() {
        return rentm;
    }

    public void setRentm(double rentm) {
        this.rentm = rentm;
    }

    public int getTake() {
        return take;
    }

    public void setTake(int take) {
        this.take = take;
    }

}
 //皮卡类
package didi;

public class PickUp extends Didi {

    public String name;
    public double rentm;
    public int take;
    public int ton;
    public int rentsum;

    public int getRentsum() {
        return rentsum;
    }

    public void setRentsum(int rentsum) {
        this.rentsum = rentsum;
    }

    public PickUp(String name, double rentm, int take,int ton) {
        // TODO Auto-generated constructor stub
        this.name=name;
        this.rentm=rentm;
        this.take=take;
        this.ton=ton;

    }
    public String getName() {
        return name;
    }

    public void setName(String name) {
        this.name = name;
    }

    public double getRentm() {
        return rentm;
    }

    public void setRentm(double rentm) {
        this.rentm = rentm;
    }

    public int getTake() {
        return take;
    }

    public void setTake(int take) {
        this.take = take;
    }
    public int getTon() {
        return ton;
    }
    public void setTon(int ton) {
        this.ton = ton;
    }

}

//main 函数类
package didi;

import java.util.Scanner;

public class Initial {

    static int is=0;
    public static void main(String[] args) {
        // TODO Auto-generated method stub

        Initial it=new Initial();

        System.out.println("请问您是否需要租车？");
        System.out.println("输入：1进入挑选      输入0：退出");

        do{
        Scanner sc=new Scanner(System.in);
        int isof=sc.nextInt();
        if(isof==0){
        System.out.println("欢迎您下次光临！");

            break;
        }else if(isof==1){
            System.out.println("请挑选你想选择的车辆！");
            is=isof;
            it.test();
            break;
        }else{
            System.out.println("输入有误，请重新输入！");
            continue;
        }
        }while(true);

    }
    public void test(){
        Didi[] carsForRent={new PassengerCar("奥迪A4",500,4),new PassengerCar("马自达6",500,4),new PickUp("皮卡雪6",450,4,2),
                new PassengerCar("金龙",800,20),new CurrentCar("松花江",400,4),new CurrentCar("依维柯",1000,20) };
        int i=1;
        if(is==1){
            for(Didi currentCar:carsForRent){
                if(currentCar instanceof PassengerCar){
                    System.out.println(""+i+"\t"+currentCar.getName()+"\t"+currentCar.getRentm()+"元/天"+"\t"+"载人:"+currentCar.getTake()+"人");
                i++;
                }
                else if(currentCar instanceof PickUp){
                    System.out.println(""+i+"\t"+currentCar.getName()+"\t"+currentCar.getRentm()+"元/天"+"\t"+"载人:"+currentCar.getTake()+"人"+"载货:"+currentCar.getTon()+"吨");
                i++;
                }else{
                    System.out.println(""+i+"\t"+currentCar.getName()+"\t"+currentCar.getRentm()+"元/天"+"\t"+"载货:"+currentCar.getTon()+"吨");
                i++;
                }
            }
        }

        double money=0;

        do{
            System.out.println("请输入你想要租车的序号(选购完成请输入0)：");
            Scanner sc=new Scanner(System.in);
            int n=sc.nextInt();

            if(n==0){
                System.out.println("欢迎您下次光临！");
                System.out.println("**租车总价格："+money+"元");
                System.out.println("**可载人的车有：");
                int sumper=0;
                for(int x=0;x<6;x++){
                    if(carsForRent[x].getRentsum()>0&&carsForRent[x].getTake()>0){
                        System.out.print(carsForRent[x].getName()+"x"+carsForRent[x].getRentsum());
                        sumper=sumper+carsForRent[x].getRentsum()*carsForRent[x].getTake();

                    }
                }
                if(sumper>0){
                System.out.println("\t"+"可载人: "+sumper+"人");
                }else{
                    System.out.println("无车可载人！");
                }
                int ton=0;
                System.out.println("**可载货的车有：");
                for(int x=0;x<6;x++){
                    if(carsForRent[x].getRentsum()>0&&carsForRent[x].getTon()>0){
                        System.out.print(carsForRent[x].getName()+"x"+carsForRent[x].getRentsum());
                        ton=ton+carsForRent[x].getRentsum()*carsForRent[x].getTon();
                    }
                }
                if(ton>0){
                System.out.println("\t"+"可载货："+ton+"吨");
                }else{
                    System.out.println("无车可载货！");
                }

            break;

            }else if(n==1||n==2||n==3||n==4||n==5||n==6)
            {       

            switch (n){
            case 1:
                System.out.println("请输入你想要租车的数量：");
                int sum=sc.nextInt();
                carsForRent[n-1].setRentsum(sum);
                double m1=500*sum;
                System.out.println("请输入你想要租用的天数：");
                money=money+m1*sc.nextInt();          
            break;
            case 2: 
                System.out.println("请输入你想要租车的数量：");
                sum=sc.nextInt();
                carsForRent[n-1].setRentsum(sum);
                m1=400*sum;
                System.out.println("请输入你想要租用的天数：");
                money=money+m1*sc.nextInt();break;
            case 3: 
                System.out.println("请输入你想要租车的数量：");
                sum=sc.nextInt();
                carsForRent[n-1].setRentsum(sum);
                m1=450*sum;
                System.out.println("请输入你想要租用的天数：");
                money=money+m1*sc.nextInt();break;
            case 4: 
                System.out.println("请输入你想要租车的数量：");
                sum=sc.nextInt();
                carsForRent[n-1].setRentsum(sum);
                m1=800*sum;
                System.out.println("请输入你想要租用的天数：");
                money=money+m1*sc.nextInt();break;
            case 5:  
                System.out.println("请输入你想要租车的数量：");
                sum=sc.nextInt();
                carsForRent[n-1].setRentsum(sum);
                m1=400*sum;
                System.out.println("请输入你想要租用的天数：");
                money=money+m1*sc.nextInt();break;
            case 6:
                System.out.println("请输入你想要租车的数量：");
                sum=sc.nextInt();
                carsForRent[n-1].setRentsum(sum);
                m1=1000*sum;
                System.out.println("请输入你想要租用的天数：");
                money=money+m1*sc.nextInt();break;

            }
            }else{
                System.out.println("输入有误，请重新输入！");
                continue;
            }

            }while(true);
    }

}
``