In
Struts Javadoc of org.apache.struts.action.ActionForm class, I found the following entry (
http://struts.apache.org/api/index.html).
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?