无论我对代码做什么，nextInt() 中的 NoSuchElementException

Question

public class MinimumElement {

public void readIntegers(int userCount) {
    int count = userCount;
    int intArray[] = new int[count];
    Scanner scan = new Scanner(System.in);

    for (int i = 0; i <= count - 1; i++) {
        int number;
        System.out.println("Please input number ");
        number = scan.nextInt();
        intArray[i] = number;
    }
    scan.close();
}

public static void main(String[] Args) {
    Scanner scan = new Scanner(System.in);
    System.out.println("Please enter the number of elements required for array");
    int userInput = scan.nextInt();
    scan.nextLine();
    scan.close();
    MinimumElement min = new MinimumElement();
    min.readIntegers(userInput);

}

}

已尝试 hasNextInt 和 hasNextLine 以及 if 条件。他们总是返回结果值 false.

Answer 1

好的，我相信我可能已经找到了解决您的问题的方法。问题在于您尝试从 System.in 读取的方式：您实际上分配了 Scanner!

的两个实例

int intArray[] = new int[count];
Scanner scan = new Scanner(System.in);

那边：

Scanner scan = new Scanner(System.in);
System.out.println("Please enter the number of elements required for array");

这会导致奇怪的问题。因此，改为创建 Scanner 的全局实例，如下例所示。

public class MinimumElement {

    private static final Scanner SCANNER = new Scanner(System.in);

    public static void main(String[] args) {
        System.out.println("Please enter the number of elements required for array");
        try {
            int userInput = SCANNER.nextInt();
            SCANNER.nextLine();
            MinimumElement min = new MinimumElement();
            min.readIntegers(userInput);
        } finally {
            SCANNER.close();
        }
    }

    public void readIntegers(int userCount) {
        int[] intArray = new int[userCount];
        for (int i = 0; i <= userCount - 1; i++) {
            int number;
            System.out.println("Please input number ");
            number = SCANNER.nextInt();
            intArray[i] = number;
        }
    }
}

请注意，您必须注意不要在调用 close() 后与 Scanner 交互，因为这也会导致错误行为。

无论我对代码做什么，nextInt() 中的 NoSuchElementException

NoSuchElementException in nextInt() no matter what I do to the code

java

java.util.scanner

nosuchelementexception