为什么 IOException 不工作但转到 InputMismatchException

Question

我不明白为什么这个简单的方法不会捕获异常，而是抛出另一个异常。弹出的异常错误是java.util.InputMismatchException。

我该怎么做才能捕捉到 IOException？

public class Throwing {

    public static void main(String[] args) {
        try {
            int x = getInt();
            System.out.println(x);
        } catch (IOException a) {
            a.printStackTrace();
        }
    }

    public static int getInt() throws IOException {
        int a = 0;
        System.out.println("Enter an interger: ");
        Scanner input = new Scanner(System.in);
        a = input.nextInt();
        return a;
    }
}

Answer 1

如果您查看 JavaDocs for Scanner#nextInt，您会发现它能够抛出 InputMismatchException，等等

But the goal is that I'm trying to throw an IOException rather than InputMismatch. Is there anything i can do to my code which will help me throw it?

您将需要捕获任何可能的异常并抛出新的 IOException 并以旧的 Exception 作为原因。

public static int getInt() throws IOException
{
    int a = 0;
    System.out.println("Enter an interger: ");
    Scanner input = new Scanner(System.in);
    try {
        a = input.nextInt();
    } catch (InputMismatchException ime) {
        throw new IOException("Could not get int from input", ime);
    }
    return a;
}

恕我直言，这不是最绝妙的主意，因为您可能希望以不同于 IOException 的方式对待 InputMismatchException，这可能是在您创建 Scanner[ 时引起的=18=]

为什么 IOException 不工作但转到 InputMismatchException

how come the IOException isn't working but goes to the InputMismatchException

java

exception

exception-handling

ioexception