I am calling my EJB method

Alessandro A. Garbagnati

I think you need to read some more regarding EJBs. Maybe the EJB specifications, or you can check some of the FAQs in the EJB Topic of this site.

The problem here is that when you need to pass an object to a method of an EJB, the object needs to be serializable. This is done implementing the java.io.Serializable interface.
The HttpServletRequest object is not serializable, that's why you are getting the java.io.NotSerializableException.