New to Java

Hi Everyone,
I'm just starting out on Java, and i've got stuck in one of my programs. Basically I'm trying to create a loop that counts the number of instances a candidate passes different exams. I've been playing with it to try and make some progress but all I have at the moment is:

  public int getCountPassMarks()
    {
        int passCount = 1;
        do
        { 
 
            if (examMarks.readInt() >= 40) passCount++;
            if (examMarks.finished()) dataFinished = true;
        }
        while (!dataFinished);
        return passCount;
    }

What i'm intending for it to do is every time it reads a mark that is greater that 40 it adds 1 to my counter variable, and then I can return the variable at the end to give the value, but I just can't get it to work. Any ideas?

Thanks for the help!