title: subclass of a serializable class needs to be serializable?
body: <p>If I have 3 classes say A and It Implements java.io.Serializable . And I have B ,which is subclass of A. If I want to serialize B , B also implements java.io.Serializable. If not Why HttpServlet implements java.io.Serializable as GenericServlet already implements it. Please clarify me .</p>
  
  <p>Thanks in Advance
  Raj</p>