java - 未知错误阻止子类的构造

Question

这是我的父类(super class):

public abstract class BankAccount
{
    private String name;
    private double balance;
    final int OVERDRAFT_FEE = 35;
    private static int accountNum=0;
    public BankAccount(String name)
    {
        this.name=name;
        balance=0;
        accountNum++;
    }

    //various methods omitted

    public abstract void endOfMonth();
    public String toString(BankAccount account)
    {
        return "Account Name: "+name+"\nBalance: $"+balance+"\nAccount Number: "+accountNum;
    }
}

这是我的子类:

public class CheckingAccount extends BankAccount
{
    final int TRANSACTION_LIMIT = 3;
    final int MINIMUM_BALANCE = 50;
    final int FEE = 10;
    private int transactionCount;

    // various methods omitted

    public void endOfMonth()
    {
        if(transactionCount>TRANSACTION_LIMIT)
        {
            int extra = transactionCount-TRANSACTION_LIMIT;
            int extra_fee = FEE*extra;
            super.setBalance((super.getBalance)-extra_fee);
        }
        if(super.getBalance()<MINIMUM_BALANCE)
        {
            super.setBalance((super.getBalance)-FEE);
        }
    }
}

在编译子类时，它给了我一个异常(exception):"constructor BankAccount in class BankAccount cannot be applied to given types; required: java.lang.String; found: no arguments; reason: actual and formal argument lists differ in length"

一开始我以为这是抽象方法的问题，但摆脱它并没有解决任何问题。想法？

Answer 1

您的父类构造函数声明为

public BankAccount(String name)

换句话说，它需要一个String参数。

通过不显式地为 CheckingAccount 类提供构造函数，Java 编译器会创建如下所示的构造函数

public CheckingAccount() {
    super();
}

换句话说，它不向您的父构造函数提供任何参数。

你需要改变这一点。使用适当的参数声明一个构造函数并将其传递给父级。

public CheckingAccount(String name) {
    super(name);
}