大神求解这个java代码怎么写

public class Account {
    private String idCard;
    private double balance;

    public Account() {
    }

    public Account(String idCard, double balance) {
        this.idCard = idCard;
        this.balance = balance;
    }

    public String getIdCard() {
        return idCard;
    }

    public void setIdCard(String idCard) {
        this.idCard = idCard;
    }

    public double getBalance() {
        return balance;
    }

    public void setBalance(double balance) {
        this.balance = balance;
    }

    @Override
    public String toString() {
        return "Account{" +
                "idCard='" + idCard + '\'' +
                ", balance='" + balance + '\'' +
                '}';
    }

    public double getInterest(){
        return 0.0;
    }
}

public class FixedDepositAccount extends Account {
    private int months;
    private double rate;

    public FixedDepositAccount() {
    }

    public FixedDepositAccount(String idCard, double balance) {
        super(idCard, balance);
    }

    public FixedDepositAccount(String idCard, double balance, int months, double rate) {
        super(idCard, balance);
        this.months = months;
        this.rate = rate;
    }

    public int getMonths() {
        return months;
    }

    public void setMonths(int months) {
        this.months = months;
    }

    public double getRate() {
        return rate;
    }

    public void setRate(double rate) {
        this.rate = rate;
    }

    @Override
    public String toString() {
        return super.getIdCard() + "账户" + super.getBalance() + "元存款的" + this.getMonths() + "月存款利息:" + (super.getBalance() * this.getRate() * this.getMonths() / 12) + "(年利率为3.50%)";
    }

    @Override
    public double getInterest() {
        return super.getInterest();
    }
}

public class BankingAccount extends Account {
    private int days;
    private double rate;

    public BankingAccount() {
    }

    public BankingAccount(String idCard, double balance) {
        super(idCard, balance);
    }

    public BankingAccount(String idCard, double balance, int days, double rate) {
        super(idCard, balance);
        this.days = days;
        this.rate = rate;
    }

    public int getDays() {
        return days;
    }

    public void setDays(int days) {
        this.days = days;
    }

    public double getRate() {
        return rate;
    }

    public void setRate(double rate) {
        this.rate = rate;
    }

    @Override
    public String toString() {
        return super.getIdCard() + "账户" + super.getBalance() + "元存款的" + this.getDays() + "天存款利息:" + (super.getBalance() * this.getRate() * this.getDays() / 365) + "(年利率为5.20%)";
    }

    @Override
    public double getInterest() {
        return super.getInterest();
    }
}

public class Test {
    public static void main(String[] args) {
        //父类引用指向子类对象
        Account fda = new FixedDepositAccount("001", 10000, 6, 3.5);
        Account ba = new BankingAccount("002", 10000, 183, 5.2);
        System.out.println(fda.toString());
        System.out.println(ba.toString());

        //正常创建对象
//        FixedDepositAccount fda = new FixedDepositAccount("001", 10000, 6, 3.5);
//        BankingAccount ba = new BankingAccount("002", 10000, 183, 5.2);
//        System.out.println(fda.toString());
//        System.out.println(ba.toString());
    }
}

不知道你这题是这意思不，不用基础知识好几年了，继承多态都快忘差不多了，测试方法里用第一个父类引用指向子类对象的，符合这题的考点