A little question regarding performance in a Java web app.

Let's assume I have a List<Rubrique> listRubriques with ten Rubrique objects.

A Rubrique contains one list of products (List<product> listProducts) and one list of clients (List<Client> listClients).

What exactly happens in memory if I do this:

listRubriques.clear(); listRubriques = null;

My point of view would be that, since listRubriques is empty, all my objects previously referenced by this list (including listProducts and listClients) will be garbage collected pretty soon. But since Collection in Java are a little bit tricky and since I have quite performance issues with my app i'm asking the question :)

edit : let's assume now that my Client object contains a List<Client>. Therefore, I have kind of a circular reference between my objects. What would happen then if my listRubrique is set to null? This time, my point of view would be that my Client objects will become "unreachable" and might create a memory leak?