Servlet::Http::HttpSession - HTTP session interface
for my $name ($session->getAttributeNames()) {
my $value = $session->getAttribute($name);
# or
$session->removeAttribute($name);
}
my $time = $session->getCreationTime();
my $id = $session->getId();
my $time = $session->getLastAccessedTime();
my $timeout = $session->getMaxInactiveInterval();
$session->invalidate();
my $bool = $session->isNew();
$session->setAttributre($name, $value);
$session->setMaxInactiveInterval($timeout);
Provides a way to identify a user across more than one page request or site
visit and to store information about that user.
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 view and manipulate information
about a session, such as the session identifier, creation time and last
accessed time, and to bind objects to sessions, allowing user information to
persist across multiple user connections.
When an application stores an object in or removes an object from
a session, the session checks whether the object implements
Servlet::Http::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 sessions that
are invalidated or expire, notifications are sent after the session has been
invalidated or expired.
When a container migrates a session between intepreters in a
distributed container setting, all session attributes implementing
Servlet::Http::HttpSessionActivationListener 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 true.
Session information is scoped only to the current web application
(Servlet::ServletContext), so information stored in one context will
not be directly visible in another.
- getAttribute($name)
- Returns the object bound with the specified name in this session, or
undef if no object is bound under the name.
Parameters:
- $name
- the name of the object
Throws:
- Servlet::Util::IllegalStateException
- if this method is called on an invalidated session
- getAttributeNames()
- Returns an array containing the names of all the objects bound to this
session, or an empty array if there are no bound objects.
Throws:
- Servlet::Util::IllegalStateException
- if this method is called on an invalidated session
- getCreationTime()
- Returns the time when this session was created, measured in seconds since
the epoch.
Throws:
- Servlet::Util::IllegalStateException
- if this method is called on an invalidated session
- getId()
- Returns the unique identifier assigned to this session. The identifier is
assigned by the servlet container and is implementation dependent.
- getLastAccessedTime()
- Returns the last time the client sent a request associated with this
session, as the number of seconds since the epoch, and marked by the time
the container received the request.
Actions that your application takes, such as getting or
setting a value associated with the session, do not affect the access
time.
- getMaxInactiveInterval()
- Returns the maximum time interval (in seconds) that the servlet container
will keep this session open between client accesses. After this interval,
the servlet container will invalidate the session. The maximum time
interval can be set with
"setMaxInactiveInterval()". A negative
time indicates the session should never time out.
- invalidate()
- Invalidates this session, then unbinds any objects bound to it.
Throws:
- Servlet::Util::IllegalStateException
- if this method is called on an invalidated session
- isNew()
- Returns true fi the client does not yet know about the session or if the
client chooses not to join the session. For example, if the server used
only cookie-based sessions, and the client had disabled the use of
cookies, then a session would be new on each request.
Throws:
- Servlet::Util::IllegalStateException
- if this method is called on an invalidated session
- removeAttribute($name)
- Removes the object bound with the specified name from this session. If the
session does not have an object bound with the specified name, this method
does nothing.
After this method executes, and if the object implements
Servlet::Http::HttpSessionBindingListener, the container calls
"valueUnbound()" on the object.
Parameters:
- $name
- the name of the object
Throws:
- Servlet::Util::IllegalStateException
- if this method is called on an invalidated session
- setAttribute($name, $value)
- Binds an object to this session using the specified name. If an object of
the same name is already bound to the session, the object is replaced.
After this method executes, and if the new object implements
Servlet::Http::HttpSessionBindingListener, the container calls
"valueBound()" on the object.
If a previously bound object was replaced, and it implements
Servlet::Http::HttpSessionBindingListener, the container calls
"valueUnbound()" on it.
Parameters:
- $name
- the name to which the object is bound
- $value
- the object to be bound
Throws:
- Servlet::Util::IllegalStateException
- if this method is called on an invalidated session
- setMaxInactiveInterval($interval)
- Specifies the time, in seconds, between client requests before the servlet
container will invalidate this session. A negative indicates the session
should never timeout.
Parameters:
- $interval
- the number of seconds
Servlet::Http::HttpSessionActivationListener,
Servlet::Http::HttpSessionBindingListener, Servlet::Http::HttpSessionContext
Brian Moseley, bcm@maz.org