javax.portlet
Interface PortletSession

public interface PortletSession

The PortletSession interface provides a way to identify a user across more than one request and to store transient information about that user.

A PortletSession is created per user client per portlet application.

A portlet can bind an object attribute into a PortletSession by name. The PortletSession interface defines two scopes for storing objects:

• APPLICATION_SCOPE
• PORTLET_SCOPE

All objects stored in the session using the APPLICATION_SCOPE must be available to all the portlets, servlets and JSPs that belongs to the same portlet application and that handles a request identified as being a part of the same session. Objects stored in the session using the PORTLET_SCOPE must be available to the portlet during requests for the same portlet window that the objects where stored from. Attributes stored in the PORTLET_SCOPE are not protected from other web components of the portlet application. They are just conveniently namespaced.

The portlet session is based on the HttpSession. Therefore all HttpSession listeners do apply to the portlet session and attributes set in the portlet session are visible in the HttpSession and vice versa.

Field Summary

static int	APPLICATION_SCOPE This constant defines an application wide scope for the session attribute.
static int	PORTLET_SCOPE This constant defines the scope of the session attribute to be private to the portlet and its included resources.

Method Summary

java.lang.Object	getAttribute(java.lang.String name) Returns the object bound with the specified name in this session under the PORTLET_SCOPE, or null if no object is bound under the name in that scope.
java.lang.Object	getAttribute(java.lang.String name, int scope) Returns the object bound with the specified name in this session, or null if no object is bound under the name in the given scope.
java.util.Enumeration	getAttributeNames() Returns an Enumeration of String objects containing the names of all the objects bound to this session under the PORTLET_SCOPE, or an empty Enumeration if no attributes are available.
java.util.Enumeration	getAttributeNames(int scope) Returns an Enumeration of String objects containing the names of all the objects bound to this session in the given scope, or an empty Enumeration if no attributes are available in the given scope.
long	getCreationTime() Returns the time when this session was created, measured in milliseconds since midnight January 1, 1970 GMT.
java.lang.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.
int	getMaxInactiveInterval() Returns the maximum time interval, in seconds, for which the portlet container keeps this session open between client accesses.
PortletContext	getPortletContext() Returns the portlet application context associated with this session.
void	invalidate() Invalidates this session (all scopes) and 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	removeAttribute(java.lang.String name) Removes the object bound with the specified name under the PORTLET_SCOPE from this session.
void	removeAttribute(java.lang.String name, int scope) Removes the object bound with the specified name and the given scope from this session.
void	setAttribute(java.lang.String name, java.lang.Object value) Binds an object to this session under the PORTLET_SCOPE, using the name specified.
void	setAttribute(java.lang.String name, java.lang.Object value, int scope) Binds an object to this session in the given scope, using the name specified.
void	setMaxInactiveInterval(int interval) Specifies the time, in seconds, between client requests, before the portlet container invalidates this session.

Field Detail

APPLICATION_SCOPE

public static final int APPLICATION_SCOPE

This constant defines an application wide scope for the session attribute. APPLICATION_SCOPE session attributes enable Portlets within one portlet application to share data.

Portlets may need to prefix attributes set in this scope with some ID, to avoid overwriting each other's attributes in the case where two portlets of the same portlet definition are created.

Value: 0x01

PORTLET_SCOPE

public static final int PORTLET_SCOPE

This constant defines the scope of the session attribute to be private to the portlet and its included resources.

Value: 0x02

Method Detail

getAttribute

public java.lang.Object getAttribute(java.lang.String name)

Returns the object bound with the specified name in this session under the PORTLET_SCOPE, or null if no object is bound under the name in that scope.

Parameters:

name - a string specifying the name of the object

Returns:

the object with the specified name for the PORTLET_SCOPE.

Throws:

java.lang.IllegalStateException - if this method is called on an invalidated session.

java.lang.IllegalArgumentException - if name is null.

getAttribute

public java.lang.Object getAttribute(java.lang.String name,
                                     int scope)

Returns the object bound with the specified name in this session, or null if no object is bound under the name in the given scope.

Parameters:

name - a string specifying the name of the object

scope - session scope of this attribute

Returns:

the object with the specified name

Throws:

java.lang.IllegalStateException - if this method is called on an invalidated session

java.lang.IllegalArgumentException - if name is null.

getAttributeNames

public java.util.Enumeration getAttributeNames()

Returns an Enumeration of String objects containing the names of all the objects bound to this session under the PORTLET_SCOPE, or an empty Enumeration if no attributes are available.

Returns:

an Enumeration of String objects specifying the names of all the objects bound to this session, or an empty Enumeration if no attributes are available.

Throws:

java.lang.IllegalStateException - if this method is called on an invalidated session

getAttributeNames

public java.util.Enumeration getAttributeNames(int scope)

Returns an Enumeration of String objects containing the names of all the objects bound to this session in the given scope, or an empty Enumeration if no attributes are available in the given scope.

Parameters:

scope - session scope of the attribute names

Returns:

an Enumeration of String objects specifying the names of all the objects bound to this session, or an empty Enumeration if no attributes are available in the given scope.

Throws:

java.lang.IllegalStateException - if this method is called on an invalidated session

getCreationTime

public long getCreationTime()

Returns the time when this session was created, measured in milliseconds since midnight January 1, 1970 GMT.

Returns:

a long specifying when this session was created, expressed in milliseconds since 1/1/1970 GMT

Throws:

java.lang.IllegalStateException - if this method is called on an invalidated session

getId

public java.lang.String getId()

Returns a string containing the unique identifier assigned to this session.

Returns:

a string specifying the identifier assigned to this session

getLastAccessedTime

public 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.

Actions that our portlet takes, such as getting or setting a value associated with the session, do not affect the access time.

Returns:

a long representing the last time the client sent a request associated with this session, expressed in milliseconds since 1/1/1970 GMT

getMaxInactiveInterval

public int getMaxInactiveInterval()

Returns the maximum time interval, in seconds, for which the portlet container keeps this session open between client accesses. After this interval, the portlet container invalidates the session. The maximum time interval can be set with the setMaxInactiveInterval method. A negative time indicates the session should never timeout.

Returns:

an integer specifying the number of seconds this session remains open between client requests

See Also:

setMaxInactiveInterval(int)

invalidate

public void invalidate()

Invalidates this session (all scopes) and unbinds any objects bound to it.

Invalidating the portlet session will result in invalidating the underlying HttpSession

Throws:

java.lang.IllegalStateException - if this method is called on a session which has already been invalidated

isNew

public boolean isNew()

Returns true if the client does not yet know about the session or if the client chooses not to join the session.

Returns:

true if the server has created a session, but the client has not joined yet.

Throws:

java.lang.IllegalStateException - if this method is called on a session which has already been invalidated

removeAttribute

public void removeAttribute(java.lang.String name)

Removes the object bound with the specified name under the PORTLET_SCOPE from this session. If the session does not have an object bound with the specified name, this method does nothing.

Parameters:

name - the name of the object to be removed from this session in the PORTLET_SCOPE.

Throws:

java.lang.IllegalStateException - if this method is called on a session which has been invalidated

java.lang.IllegalArgumentException - if name is null.

removeAttribute

public void removeAttribute(java.lang.String name,
                            int scope)

Removes the object bound with the specified name and the given scope from this session. If the session does not have an object bound with the specified name, this method does nothing.

Parameters:

name - the name of the object to be removed from this session

scope - session scope of this attribute

Throws:

java.lang.IllegalStateException - if this method is called on a session which has been invalidated

java.lang.IllegalArgumentException - if name is null.

setAttribute

public void setAttribute(java.lang.String name,
                         java.lang.Object value)

Binds an object to this session under the PORTLET_SCOPE, using the name specified. If an object of the same name in this scope is already bound to the session, that object is replaced.

After this method has been executed, and if the new object implements HttpSessionBindingListener, the container calls HttpSessionBindingListener.valueBound. The container then notifies any HttpSessionAttributeListeners in the web application.

If an object was already bound to this session that implements HttpSessionBindingListener, its HttpSessionBindingListener.valueUnbound method is called.

If the value is null, this has the same effect as calling removeAttribute().

Parameters:

name - the name to which the object is bound under the PORTLET_SCOPE; this cannot be null.

value - the object to be bound

Throws:

java.lang.IllegalStateException - if this method is called on a session which has been invalidated

java.lang.IllegalArgumentException - if name is null.

setAttribute

public void setAttribute(java.lang.String name,
                         java.lang.Object value,
                         int scope)

Binds an object to this session in the given scope, using the name specified. If an object of the same name in this scope is already bound to the session, that object is replaced.

After this method has been executed, and if the new object implements HttpSessionBindingListener, the container calls HttpSessionBindingListener.valueBound. The container then notifies any HttpSessionAttributeListeners in the web application.

If an object was already bound to this session that implements HttpSessionBindingListener, its HttpSessionBindingListener.valueUnbound method is called.

If the value is null, this has the same effect as calling removeAttribute().

Parameters:

name - the name to which the object is bound; this cannot be null.

value - the object to be bound

scope - session scope of this attribute

Throws:

java.lang.IllegalStateException - if this method is called on a session which has been invalidated

java.lang.IllegalArgumentException - if name is null.

setMaxInactiveInterval

public void setMaxInactiveInterval(int interval)

Specifies the time, in seconds, between client requests, before the portlet container invalidates this session. A negative time indicates the session should never timeout.

Parameters:

interval - An integer specifying the number of seconds

getPortletContext

public PortletContext getPortletContext()

Returns the portlet application context associated with this session.

Returns:

the portlet application context