Java 循环困惑

Question

我编写了这段代码，旨在读取具有整数值的文件。如果整数值 >= 0 且 <=100，我需要给出成绩的平均值。如果有任何值超出指定范围 0-100，那么我需要计算不正确的整数等级，通知用户不正确的等级，并告知有多少不正确的等级。我尝试了该代码，但我不断收到错误代码:

Exception in thread "main" java.util.NoSuchElementException
at java.util.Scanner.throwFor(Unknown Source)
at java.util.Scanner.next(Unknown Source)
at Project9.main(Project9.java:26)

代码示例:

public static void main(String[] args) throws IOException{
    String file;
    int readInts;

    Scanner k = new Scanner(System.in);

    System.out.println("Enter filename: ");
    file = k.nextLine();
    int counterWrong = 0;
    int counterRight = 0;
    int sum = 0;
    double average = 1.0 * sum/counterRight;

    File fileReader = new File(file);

    if (fileReader.exists()) {
        Scanner input = new Scanner(fileReader);
        while (input.hasNext()) {
            readInts = input.nextInt();
            System.out.println(readInts);
            String a = input.next();
            int a2 = Integer.parseInt(a);

        if (a2 <= 100 && a2 >= 0){
            counterRight++;            
            sum = sum + a2; 
            System.out.println("Score " + a2 + " was counted.");

        } else {
            counterWrong++;
            System.out.println("The test grade " + a2 + " was not scored as it was out of the range of valid scores.");
            System.out.println("There were " + counterWrong + " invalid scores that were not counted.");
        }
        }
        if (counterRight > 0){
            System.out.println("The average of the correct grades on file is " + average + ".");
        }
    } else {
        System.out.println("The file " + file + " does not exist. The program will now close.");
    }


}

}

Answer 1

您正在执行一次检查hasNext，但随后您使用nextInt()和next()从扫描仪读取两次。