The servlet container uses this interface to create a session
between an HTTP client and an HTTP server. The session persists
for a specified time period, across more than one connection or
page request from the user. A session usually corresponds to one
user, who may visit a site many times. The server can maintain a
session in many ways such as using cookies or rewriting URLs.
This interface allows servlets to
When an application stores an object in or removes an object from a
session, the session checks whether the object implements
HttpSessionBindingListener . If it does,
the servlet notifies the object that it has been bound to or unbound
from the session. Notifications are sent after the binding methods complete.
For session that are invalidated or expire, notifications are sent after
the session has been invalidatd or expired.
When container migrates a session between VMs in a distributed container
setting, all session attributes implementing the HttpSessionActivationListener
interface are notified.
A servlet should be able to handle cases in which
the client does not choose to join a session, such as when cookies are
intentionally turned off. Until the client joins the session,
isNew returns true. If the client chooses
not to join
the session, getSession will return a different session
on each request, and isNew will always return
Session information is scoped only to the current web application
(ServletContext), so information stored in one context
will not be directly visible in another.