servlet A receives a request that it forward to servlet B within another web application in the same web container servlet A need to share data with servlet B and data must be not visible to other servlets in A's web application in which object can the data that A shares with B be stored
It should be the 4th one(HttpServletRequest), because only the servlet who is handling the request will be able to get the data through HttpServletRequest.
I replied to your earlier topic, which was exactly the same as this one but with a different title, and asked you not to cross post. Deleting that last topic (along with my response) and posting it again not only wastes the time of ranchers who are trying to help you out, but is also extremely rude.
“Programming today is a race between software engineers striving to build bigger and better idiot-proof programs, and the Universe trying to produce bigger and better idiots. So far, the Universe is winning.” - Rich Cook