org.jsecurity.session
Interface Session

All Known Subinterfaces:

ValidatingSession

All Known Implementing Classes:

DelegatingSession, ImmutableProxiedSession, ProxiedSession, SimpleSession, WebSession

public interface Session

A Session is a stateful data context associated with a single Subject (user, 3rd party process, etc) who interacts with a software system over a period of time.

A Session is intended to be managed by the business tier and accessible via other tiers without being tied to any given client technology. This is a great benefit to Java systems, since until now, the only viable session mechanisms were the HttpSession or Stateful Session EJB's, which many times unnecessarily coupled applications to web or ejb technologies.

See the SessionFactory.getSession(Serializable) JavaDoc for more on the benefits of a POJO-based Session framework.

Since:

0.1

Author:

Les Hazlewood

Method Summary

Object	getAttribute(Object key) Returns the object bound to this session identified by the specified key.
Collection<Object>	getAttributeKeys() Returns the keys of all the attributes stored under this session.
InetAddress	getHostAddress() Returns the InetAddress of the host that originated this session, or null if the host address is unknown.
Serializable	getId() Returns the unique identifier assigned by the system upon session creation.
Date	getLastAccessTime() Returns the last time the user associated with the session interacted with the system.
Date	getStartTimestamp() Returns the time the session was started; that is, the time the system created the instance.
long	getTimeout() Returns the time in milliseconds that the session session may remain idle before expiring.
Object	removeAttribute(Object key) Removes (unbinds) the object bound to this session under the specified key name.
void	setAttribute(Object key, Object value) Binds the specified value to this session, uniquely identified by the specifed key name.
void	setTimeout(long maxIdleTimeInMillis) Sets the time in milliseconds that the session may remain idle before expiring.
void	stop() Explicitly stops (invalidates) this session and releases all associated resources.
void	touch() Explicitly updates the lastAccessTime of this session.

Method Detail

getId

Serializable getId()

Returns the unique identifier assigned by the system upon session creation.

All return values from this method are expected to have proper toString(), equals(), and hashCode() implementations. Good candiadates for such an identifier are UUIDs, Integers, and Strings.

Returns:

The unique identifier assigned to the session upon creation.

getStartTimestamp

Date getStartTimestamp()

Returns the time the session was started; that is, the time the system created the instance.

Returns:

The time the system created the session.

getLastAccessTime

Date getLastAccessTime()

Returns the last time the user associated with the session interacted with the system.

Returns:

The time the user last interacted with the system.

See Also:

touch()

getTimeout

long getTimeout()
                throws InvalidSessionException

Returns the time in milliseconds that the session session may remain idle before expiring.

• A negative return value means the session will never expire.
• A non-negative return value (0 or greater) means the session expiration will occur if idle for that length of time.

Returns:

the time in milliseconds the session may remain idle before expiring.

Throws:

InvalidSessionException - if the session has been stopped or expired prior to calling this method.

Since:

0.2

setTimeout

void setTimeout(long maxIdleTimeInMillis)
                throws InvalidSessionException

Sets the time in milliseconds that the session may remain idle before expiring.

• A negative return value means the session will never expire.
• A non-negative return value (0 or greater) means the session expiration will occur if idle for that length of time.

Parameters:

maxIdleTimeInMillis - the time in milliseconds that the session may remain idle before expiring.

Throws:

InvalidSessionException - if the session has been stopped or expired prior to calling this method.

Since:

0.2

getHostAddress

InetAddress getHostAddress()

Returns the InetAddress of the host that originated this session, or null if the host address is unknown.

Returns:

the InetAddress of the host that originated this session, or null if the host address is unknown.

See Also:

SessionFactory.start(java.net.InetAddress)

touch

void touch()
           throws InvalidSessionException

Explicitly updates the lastAccessTime of this session. This method can be used to ensure a session does not time out.

Most programmers won't use this method explicitly and will instead rely calling the other Session methods to update the time transparently, or on a framework during a remote procedure call or upon a web request.

This method is particularly useful however when supporting rich-client applications such as Java Web Start appp, Java or Flash applets, etc. Although rare, it is possible in a rich-client environment that a user continuously interacts with the client-side application without a server-side method call ever being invoked. If this happens over a long enough period of time, the user's server-side session could time-out. Again, such cases are rare since most rich-clients frequently require server-side method invocations.

In this example though, the user's session might still be considered valid because the user is actively "using" the application, just not communicating with the server. But because no server-side method calls are invoked, there is no way for the server to know if the user is sitting idle or not, so it must assume so to maintain session integrity. The touch method could be invoked by the rich-client application code during those times to ensure that the next time a server-side method is invoked, the invocation will not throw an ExpiredSessionException. In short terms, it could be used periodically to ensure a session does not time out.

How often this rich-client "maintenance" might occur is entirely dependent upon the application and would be based on variables such as session timeout configuration, usage characteristics of the client application, network utilization and application server performance.

Throws:

InvalidSessionException - if this session has stopped or expired prior to calling this method.

stop

void stop()
          throws InvalidSessionException

Explicitly stops (invalidates) this session and releases all associated resources.

If this session has already been authenticated (i.e. the Subject that owns this session has logged-in), calling this method explicitly might have undesired side effects:

It is common for a Subject implementation to retain authentication state in the Session. If the session is explicitly stopped by application code by calling this method directly, it could clear out any authentication state that might exist, thereby effectively "unauthenticating" the Subject.

As such, you might consider logging-out the 'owning' Subject instead of manually calling this method, as a log out is expected to stop the corresponding session automatically, and also allows framework code to execute additional cleanup logic.

Throws:

InvalidSessionException - if this session has stopped or expired prior to calling this method.

getAttributeKeys

Collection<Object> getAttributeKeys()
                                    throws InvalidSessionException

Returns the keys of all the attributes stored under this session. If there are no attributes, this returns an empty collection.

Returns:

the keys of all attributes stored under this session, or an empty collection if there are no session attributes.

Throws:

InvalidSessionException - if this session has stopped or expired prior to calling this method.

Since:

0.2

getAttribute

Object getAttribute(Object key)
                    throws InvalidSessionException

Returns the object bound to this session identified by the specified key. If there is no object bound under the key, null is returned.

Parameters:

key - the unique name of the object bound to this session

Returns:

the object bound under the specified key name or null if there is no object bound under that name.

Throws:

InvalidSessionException - if this session has stopped or expired prior to calling this method.

setAttribute

void setAttribute(Object key,
                  Object value)
                  throws InvalidSessionException

Binds the specified value to this session, uniquely identified by the specifed key name. If there is already an object bound under the key name, that existing object will be replaced by the new value.

If the value parameter is null, it has the same effect as if removeAttribute(key) was called.

Parameters:

key - the name under which the value object will be bound in this session

value - the object to bind in this session.

Throws:

InvalidSessionException - if this session has stopped or expired prior to calling this method.

removeAttribute

Object removeAttribute(Object key)
                       throws InvalidSessionException

Removes (unbinds) the object bound to this session under the specified key name.

Parameters:

key - the name uniquely identifying the object to remove

Returns:

the object removed or null if there was no object bound under the name key.

Throws:

InvalidSessionException - if this session has stopped or expired prior to calling this method.