Question

我在创建自己的异常类时遇到了一个相当小的问题。我已经扩展它，并试图在构造函数中收到一个double，但我一直在收到错误。

bankaccount @withdraw里面的错误“不兼容的类型：InsufficientFundsException无法转换为throwable”

异常类：

    public class InsufficientFundsException extends RuntimeException {

    private double shortFall;   

    public InsufficientFundsException(double a) {
        super("Insufficient funds");
        shortFall = a;
    }

    public double getAmount() { return shortFall; }

}

银行帐户类：

public class BankAccount {

    private int accountNumber;
    private double balance;

    // Class constructor
    public BankAccount(int account) {
        accountNumber = account;
        balance = 0.0;
    }

    public int getAccountNumber() {

        return accountNumber;
    }

    public double getBalance()
    {
        return balance;
    }

    public void deposit(double b) {
        balance += b;
    }

    public void withdraw(double w) throws InsufficientFundsException {

        double difference;
        if(w > balance) {
            difference = w - balance;           
        } else {
            balance -= w;   
        }
    }

除非提款额大于当前余额，否则我想提款。在这种情况下，我想抛出异常。我也尝试在if中抛出异常但是得到：

类中的

构造函数InsufficientFundsException InsufficientFundsException不能应用于给定类型; 必需：没有参数发现：双倍原因：实际和正式的参数列表长度不同

 public void withdraw(double w)  {

        double difference;
        if(w > balance) {
            difference = w - balance; 
            Exception ex =  new InsufficientFundsException(difference);
        } else {
            balance -= w;   
        }
    }

我只有一个构造函数。任何建议或帮助表示赞赏。

Answer 1

你试过......

throw new InsufficientFundsException(difference);

取代

Exception ex =  new InsufficientFundsException(difference);

通常会抛出异常。

更新了代码段...

public void withdraw(double w) throws InsufficientFundsException {

    double difference;
    if(w > balance) {
        difference = w - balance;    
        throw new InsufficientFundsException(difference);
    } else {
        balance -= w;   
    }
}

随着......

public static void main(String[] args){
    BankAccount account = new BankAccount(1);
    account.withdraw(5.0);
}

... GOT

Exception in thread "main" com.misc.help.InsufficientFundsException:     Insufficient funds
at com.misc.help.BankAccount.withdraw(BankAccount.java:32)
at com.misc.help.BankAccount.main(BankAccount.java:40)

Java自定义异常类

1 个答案: