Reflection: Gather info about Subclass Fields

Question

I have a system that works as follows:
I have written an abstract base class (say ClassA) to be used in an application I am developing. The intention is that another programmer may come and subclass ClassA several times, creating different versions.
In the subclasses, I would expect there to be an arbitrary number of objects of another class, ClassB. I need to be able to perform a method from ClassA on each and every object of ClassB.
In order to make the designing of the subclass easier, I would like to be able to call a single method of ClassA that would inspect itself to find all the objects of ClassB, rather than forcing the other programmer to call the method of ClassA for EACH object.
THE PROBLEM:
When I obtain this.getClass() from within ClassA, the fields of the class object come up NULL. It seemingly has no fields, constructors, methods, etc. The Class object itself is not null, but it's fields are.
Can anyone explain to me why this is? Can anyone suggest a solution to me?

Answer 1

Here's a quick example of what I had in mind based on the information provided. Caveat: it has a high likelihood of not meeting your exact requirements.
abstract class ClassA {
    void perform() {
        for (ClassB b : getBs()) b.specialMethod();
    public abstract void add(ClassB cb) { }
    protected abstract Collection getBees() { }
class SubclassOfA extends ClassA {
    private Collection<ClassB> bees = new ArrayList<ClassB>();
    public void add(ClassB bee) {
        bees.add(bee);
    protected Collection getBees() {
        return Collections.unmodifiableCollection(bees);
interface myInterface {
    void specialMethod();
/** Arbitrary Object **/
class ClassB implements myInterface {
    public void specialMethod() { }   
}