And you attempt retrieve their values without specifying the appropriate context

■

■

request This puts or retrieves the attribute from the Request scope and is thus available during the lifecycle of the current HTTP request, pos-sibly spanning multiple JavaServer Pages and Servlets.This Request scope is analogous to calling the ServletRequest.getAttribute() and
ServletRequest.setAttribute() methods.

session This puts or retrieves the attribute from the Session scope and is thus available during the current user browser session’s lifecycle.This scope is analogous to calling the HttpSession.getAttribute() and
HttpSession.setAttribute() methods.