This week's book giveaway is in the OCPJP forum. We're giving away four copies of OCA/OCP Java SE 7 Programmer I & II Study Guide and have Kathy Sierra & Bert Bates on-line! See this thread for details.
I don't know the answer to your question, but I suspect that you're asking the wrong question. The right question is "How do I accomplish what I want to accomplish by putting all my Java code in the Action class?". I believe if you ask yourself this question, you will find a better solution than if you answer your original question.