Measure the Positional stability of a Class using reflection api

As part of a project for college we are required to " create a Java application that uses reflection to analyse an arbitrary Java Application Archive (JAR) and calculates the positional stability of each of the component classes in its object graph Recall that the Positional Stability (I) of a type can be measured by counting the number of dependencies that enter and leave that type:".

We need to measure the Efferent and Afferent couplings of each class and it components, then calculate the stability.

I am a little confused at how to calculate the Afferent and Efferent couplings. This is what I have done so far,

 for (int i = 0; i < cls.size(); i++) {

        Class cla = cls.getMyClass(i);

        Class[] interfaces = cla.getInterfaces();

        for(Class inter : interfaces){

            efferentCoup++;
        }

        Constructor[] cons = cla.getConstructors();
        Class[] conParams;

        for(Constructor c: cons){

            conParams = c.getParameterTypes();

            for(Class par: conParams){

                efferentCoup++;
            }

        }

        Field[] fields = cla.getFields();

        for(Field fie: fields ){
            efferentCoup++;
        }
}