public interface HttpSession
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 invalidated 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 true
.
Session information is scoped only to the current web application (ServletContext
), so information
stored in one context will not be directly visible in another.
HttpSessionBindingListener
,
HttpSessionContext
Modifier and Type | Method and Description |
---|---|
Object |
getAttribute(String name)
Returns the object bound with the specified name in this session, or
null if no object is bound
under the name. |
Enumeration<String> |
getAttributeNames()
Returns an
Enumeration of String objects containing the names of all the objects bound
to this session. |
long |
getCreationTime()
Returns the time when this session was created, measured in milliseconds since midnight January 1, 1970 GMT.
|
String |
getId()
Returns a string containing the unique identifier assigned to this session.
|
long |
getLastAccessedTime()
Returns the last time the client sent a request associated with this session, as the number of milliseconds since
midnight January 1, 1970 GMT, and marked by the time the container received the request.
|
int |
getMaxInactiveInterval()
Returns the maximum time interval, in seconds, that the servlet container will keep this session open between
client accesses.
|
ServletContext |
getServletContext()
Returns the ServletContext to which this session belongs.
|
HttpSessionContext |
getSessionContext()
Deprecated.
As of Version 2.1, this method is deprecated and has no replacement. It will be removed in a future
version of Jakarta Servlets.
|
Object |
getValue(String name)
Deprecated.
As of Version 2.2, this method is replaced by
getAttribute(java.lang.String) . |
String[] |
getValueNames()
Deprecated.
As of Version 2.2, this method is replaced by
getAttributeNames() |
void |
invalidate()
Invalidates this session then unbinds any objects bound to it.
|
boolean |
isNew()
Returns
true if the client does not yet know about the session or if the client chooses not to join
the session. |
void |
putValue(String name,
Object value)
Deprecated.
As of Version 2.2, this method is replaced by
setAttribute(java.lang.String, java.lang.Object) |
void |
removeAttribute(String name)
Removes the object bound with the specified name from this session.
|
void |
removeValue(String name)
Deprecated.
As of Version 2.2, this method is replaced by
removeAttribute(java.lang.String) |
void |
setAttribute(String name,
Object value)
Binds an object to this session, using the name specified.
|
void |
setMaxInactiveInterval(int interval)
Specifies the time, in seconds, between client requests before the servlet container will invalidate this
session.
|
long getCreationTime()
long
specifying when this session was created, expressed in milliseconds since 1/1/1970
GMTIllegalStateException
- if this method is called on an invalidated sessionString getId()
long getLastAccessedTime()
Actions that your application takes, such as getting or setting a value associated with the session, do not affect the access time.
long
representing the last time the client sent a request associated with this session,
expressed in milliseconds since 1/1/1970 GMTIllegalStateException
- if this method is called on an invalidated sessionServletContext getServletContext()
void setMaxInactiveInterval(int interval)
An interval value of zero or less indicates that the session should never timeout.
interval
- An integer specifying the number of secondsint getMaxInactiveInterval()
setMaxInactiveInterval
method.
A return value of zero or less indicates that the session will never timeout.
setMaxInactiveInterval(int)
@Deprecated HttpSessionContext getSessionContext()
HttpSessionContext
for this session.Object getAttribute(String name)
null
if no object is bound
under the name.name
- a string specifying the name of the objectIllegalStateException
- if this method is called on an invalidated session@Deprecated Object getValue(String name)
getAttribute(java.lang.String)
.name
- a string specifying the name of the objectIllegalStateException
- if this method is called on an invalidated sessionEnumeration<String> getAttributeNames()
Enumeration
of String
objects containing the names of all the objects bound
to this session.Enumeration
of String
objects specifying the names of all the objects bound
to this sessionIllegalStateException
- if this method is called on an invalidated session@Deprecated String[] getValueNames()
getAttributeNames()
String
objects specifying the names of all the objects bound to this sessionIllegalStateException
- if this method is called on an invalidated sessionvoid setAttribute(String name, Object value)
After this method executes, and if the new object implements HttpSessionBindingListener
, the
container calls HttpSessionBindingListener.valueBound
. The container then notifies any
HttpSessionAttributeListener
s in the web application.
If an object was already bound to this session of this name that implements
HttpSessionBindingListener
, its HttpSessionBindingListener.valueUnbound
method is
called.
If the value passed in is null, this has the same effect as calling removeAttribute()
.
name
- the name to which the object is bound; cannot be nullvalue
- the object to be boundIllegalStateException
- if this method is called on an invalidated session@Deprecated void putValue(String name, Object value)
setAttribute(java.lang.String, java.lang.Object)
name
- the name to which the object is bound; cannot be nullvalue
- the object to be bound; cannot be nullIllegalStateException
- if this method is called on an invalidated sessionvoid removeAttribute(String name)
After this method executes, and if the object implements HttpSessionBindingListener
, the container
calls HttpSessionBindingListener.valueUnbound
. The container then notifies any
HttpSessionAttributeListener
s in the web application.
name
- the name of the object to remove from this sessionIllegalStateException
- if this method is called on an invalidated session@Deprecated void removeValue(String name)
removeAttribute(java.lang.String)
name
- the name of the object to remove from this sessionIllegalStateException
- if this method is called on an invalidated sessionvoid invalidate()
IllegalStateException
- if this method is called on an already invalidated sessionboolean isNew()
true
if 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.true
if the server has created a session, but the client has not yet joinedIllegalStateException
- if this method is called on an already invalidated sessionCopyright © 2021 JBoss by Red Hat. All rights reserved.