JFileChooser选择输入文件java.util.InputMismatchException错误

Question

在我的程序中，我正在尝试使用JFileChooser选择输入文件并在colsole中显示输出。如果我在该文件中选择grade.txt文件，我会有不同的等级，如：

20 98.83 40.05 0.97 9.77 87.73 87.80 99.15 94.77 41.39 

输出看起来像：

Student 1 score is 98.83 and grade is A
Student 2 score is 40.05 and grade is F
Student 3 score is 0.97 and grade is F

当我试图运行我的程序时，我在线程“main”中得到了Exception

java.util.InputMismatchException
    at java.util.Scanner.throwFor(Unknown Source)
    at java.util.Scanner.next(Unknown Source)
    at java.util.Scanner.nextInt(Unknown Source)
    at java.util.Scanner.nextInt(Unknown Source)
    at Homework10.A.main(A.java:23)

我该如何解决此错误？

public class A {

 public static void main(String[] args) throws FileNotFoundException {

     Scanner user = new Scanner(System.in);

        JFileChooser jfc = new JFileChooser(".");
        int jfcUserOption = jfc.showOpenDialog(null);
        if (jfcUserOption == JFileChooser.APPROVE_OPTION){
        File chosenFile = jfc.getSelectedFile();

        Scanner input = new Scanner( chosenFile ); 

        while(input.hasNext()){
            int n = input.nextInt();
            int bestScore = 0;
            int[] score = new int[n];
            for (int i = 0; i < score.length; i++) {
           score[i] = input.nextInt();
           if (bestScore < score[i]) {
            bestScore = score[i];
           }
          }



          char grade;
          for (int i = 1; i < score.length; i++) {
           if (score[i] >= bestScore - 10)
            grade = 'A';
           else if (score[i] >= bestScore - 20)
            grade = 'B';
           else if (score[i] >= bestScore - 30)
            grade = 'C';
           else if (score[i] >= bestScore - 40)
            grade = 'D';
           else
            grade = 'F';

           System.out.println("Student " + i +" score is " + score[i] +" and grade is " + grade);
          }

         }

 }
}
}