将变量从一个类传递到另一个类，而无需更改方法名称

Question

I have a class Course that needs to pass a JUnit case in a test class, therefore the method name getNumberStudents needs to remain the same.

public class Course {

private Students students = null;

public Course(Students students, Grades grades) {
    this.students = students;
}
public int getNumberStudents() {
    int numberStudents = 0;     
    numberstudents = students.getNumberStudents();      
    return numberStudents;
}

However, I need to access the data using another class, 'Students'. Due to how the test class is setup, I can't modify the method signature in this class either. Can someone please tell me how I can pass the result I am printing out in the Students class to the Course class?

public class Students {

public Students(String studentsDb) {
    try {
        FileInputStream file = new FileInputStream(new File(studentsDb));

        XSSFWorkbook workbook = new XSSFWorkbook(file);

        int numberStudents = 0;

        // Get first sheet from the workbook
        XSSFSheet sheet = workbook.getSheetAt(0);

        // Iterate through each rows from first sheet
        Iterator<Row> rowIterator = sheet.iterator();
        while (rowIterator.hasNext()) {
            Row row = rowIterator.next();
            if (row.getRowNum() == 0) {
                continue;
            }
            numberStudents = numberStudents + 1;
        }
        System.out.println(numberStudents);

    } catch (FileNotFoundException e) {
        e.printStackTrace();
    } catch (IOException e) {
        e.printStackTrace();
    }

Or, is there a simpler way to do this? Thanks.

Answer 1

Can you do something like:

public Class Students {
    private int numStudents;

    public Students(String studentsDb) {
        //Keep everything the same

        //add this line under the print statement:
        this.numStudents = numberStudents;
    }

    public int getNumberStudents() {
        return numStudents;
    }
}

Then in your Course class you can now do students.getNumberStudents();