java - 为什么这种获取用户输入的方法不起作用？

Question

我有以下代码，用于让用户输入一个整数，检查以确保输入有效，如果无效，则再次要求输入。当代码运行时，一切正常，直到给出一些无效输入，此时代码循环而不会暂停再次请求输入，直到发生堆栈溢出，我不知道为什么。代码:

//Create the scanner object
private static Scanner in = new Scanner(System.in);

//Function to get input in integer form, complete with exception handling
//A value of -1 means the user is done inputing
public static int getInt()
{
    int num;

    //Begin try block
    try
    {
        //Get the user to input an integer
        num = in.nextInt();

        //Make sure the integer is positive. Throw an exception otherwise
        if (num < -1)
            throw new InputMismatchException();
    }

    //If an exception occurred during the inputting process, recursively call this function
    catch (InputMismatchException e)
    {
        System.out.println("Error: Input must be a positive integer, or -1.");
        System.out.print("Enter a score: ");
        num = getInt();
    }

    //Return the inputed number
    return num;
}

Answer 1

When a scanner throws an InputMismatchException, the scanner will not pass the token that caused the exception, so that it may be retrieved or skipped via some other method

javadoc 是这么说的，即不是数字的字符串不会自动从输入中删除。手动调用 in.next() 将其丢弃。