谁能帮助我使此Java运行无误？

Question

I keep getting error "Error: Could not find or load main class GradesAverage" after trying to compile it. Can anyone help me understand where it went wrong in this code?

package javaexercises.arrays;

import java.util.Scanner;

public class GradesAverage {

    private final int LOWEST_GRADE  = 0;
    private final int HIGHEST_GRADE = 100;

    // student's grades
    private int[] grades;

    private Scanner in;

    /**
     * Enter program's point.
     * 
     * @param args 
     */
    public static void main(String[] args)
    {
        GradesAverage aGradesAverage = new GradesAverage();
        aGradesAverage.in = new Scanner(System.in);

        System.out.print("Enter the number of students: ");
        int numStudents = aGradesAverage.in.nextInt();

        aGradesAverage.run(numStudents);
    }

    /**
     * Run program.
     * 
     * @param numStudents 
     */
    private void run(int numStudents)
    {
        if (numStudents <= 0) {
            System.out.println("Invalid number of students.");
            return;
        }        
        grades = new int[numStudents];

        double sum = 0;
        int    i   = 0;
        while (i < numStudents)
        {
            System.out.printf("Enter the grade for student %1$d: ", (i+1));
            int grade = in.nextInt();

            // chek if grade is between 0 and 100
            if ((grade >= LOWEST_GRADE) && (grade <= HIGHEST_GRADE)) {
                grades[i] = grade;
                sum      += grade;
                i++;
                continue;
            }
            System.out.println("Invalid grade, try again...");
        }
        System.out.printf("The average is %1$.2f\n", (sum / numStudents));
    }

}

Answer 1

Some online compilers don't handle packaging well.

Comment out this line

package javaexercises.arrays;

It should work.