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.
ActionForms are JavaBeans, subclasses should also implement Serializable, as required by the JavaBean specification.
But as we know from Java language basics, if a super class A implements an interface X, then any instance of subclass of class A, for example B that extends class A, will be automatically an instance of C as well. Then why a subclass of ActionForm should implement Serializable again as ActionFrom itself implements Serializable interface?
Ashik Uzzaman Senior Member of Technical Staff, Salesforce.com, San Francisco, CA, USA.