I may be misunderstanding what you're saying, but the way it's phrased it sounds wrong.
To make a session serializable, all objects put into the session must be serializable. The servlet doesn't have to do anything special. Is that what you're asking? [ August 31, 2007: Message edited by: Ulf Dittmer ]
What do you want to achieve by serializing a session. We normally serailize the attributes attached to the session of a distributed web app.
I have heard of synchronization of session but haven't heard about serializing of session. Moreover I don't think we serialize a method. We serialize a class by making them to implement marker interface Serailizable. Please explain it a little more.