com.amadeus.session

Class SessionManager

java.lang.Object

com.amadeus.session.SessionManager

All Implemented Interfaces:

Closeable, AutoCloseable

public class SessionManager
extends Object
implements Closeable

Main class responsible for managing sessions. The class offers strategy for retrieving, creating, propagating and deleting session. It also offers services for scheduling and executing task asynchronously.

In case of servlet engines, one session manager will be created per ServletContext.

The manager provides following metrics:

• `com.amadeus.session.created` measures total number of created sessions as well as rate of sessions created in last 1, 5 and 15 minutes
• `com.amadeus.session.deleted` measures total number of deleted sessions as well as rate of sessions measures rate of sessions deleted in last 1, 5 and 15 minutes
• `com.amadeus.session.missing` measures total number of session which were not found in repository, as measures rate of such occurrences in last 1, 5 and 15 minutes
• `com.amadeus.session.retrieved` measures total number of session retrievals as well as measures rate of sessions retrieval from store in last 1, 5 and 15 minutes
• `com.amadeus.session.timers.commit` measures histogram (distribution) of elapsed time during commit as well as total number of commits and rate of commits over last 1, 5 and 15 minutes
• `com.amadeus.session.timers.fetch` measures histogram (distribution) of elapsed time during fetch of session data from repository as well as total number of fetch requests and rate of fetch requests over last 1, 5 and 15 minutes

Field Summary

Fields

Modifier and Type	Field and Description
protected SessionConfiguration	configuration
protected ExecutorFacade	executors
protected SessionFactory	factory
protected SessionNotifier	notifier
protected SessionRepository	repository
protected SerializerDeserializer	serializerDeserializer
protected SessionTracking	tracking

Constructor Summary

Constructors

Constructor and Description
SessionManager(ExecutorFacade executors, SessionFactory factory, SessionRepository repository, SessionTracking tracking, SessionNotifier notifier, SessionConfiguration configuration, ClassLoader classLoader) Constructor.

Method Summary

Modifier and Type	Method and Description
void	close() Called to shutdown the session manager and perform needed cleanup.
void	delete(String sessionId, boolean expired) Deletes session from repository and performs orderly cleanup.
void	deleteAsync(String sessionId, boolean expired) Deletes list of sessions.
String	encodeUrl(RequestWithSession request, String url) Called to encode URL based on session tracking.
SessionConfiguration	getConfiguration() Configuration for this SessionManager
com.codahale.metrics.MetricRegistry	getMetrics() Retrieves metric registry for this session manager.
SessionNotifier	getNotifier() Returns SessionNotifier used by this instance.
SessionRepository	getRepository() Returns SessionRepository used by this instance.
SerializerDeserializer	getSerializerDeserializer() Serialiazer/deserializer to use when storing to repository.
RepositoryBackedSession	getSession(RequestWithSession request, boolean create, String forceId) Builds or retrieves session.
ClassLoader	getSessionClassLoader() Returns class loader to be used for session objects.
void	invalidationConflict(RepositoryBackedSession session, boolean onExpiry) Called by RepositoryBackedSession when a conflict occurs during invalidation of session.
void	invokeCommit(RepositoryBackedSession session) Calls RepositoryBackedSession.Committer for the passed RepositoryBackedSession and measures time of execution.
void	propagateSession(RequestWithSession request, ResponseWithSessionId response) Propagates the session id to the response.
void	remove(SessionData sessionData)
void	requestFinished() Called when request has been finished.
ScheduledFuture<?>	schedule(String timer, Runnable task, long period) Schedules the tasks to execute with a ScheduledExecutorService with the specified period.
Future<?>	submit(String timer, Runnable task) Executes task in separate thread.
void	switchSessionId(RepositoryBackedSession session) Changes session id of the passed session.
String	toString()

Methods inherited from class java.lang.Object

clone, equals, finalize, getClass, hashCode, notify, notifyAll, wait, wait, wait

Field Detail

repository

protected final SessionRepository repository

notifier

protected final SessionNotifier notifier

tracking

protected final SessionTracking tracking

factory

protected final SessionFactory factory

executors

protected final ExecutorFacade executors

configuration

protected final SessionConfiguration configuration

serializerDeserializer

protected final SerializerDeserializer serializerDeserializer

Constructor Detail

SessionManager

public SessionManager(ExecutorFacade executors,
                      SessionFactory factory,
                      SessionRepository repository,
                      SessionTracking tracking,
                      SessionNotifier notifier,
                      SessionConfiguration configuration,
                      ClassLoader classLoader)

Constructor.

Parameters:

executors - thread scheduler

factory - creates memory representation of session

repository - repository should be namespace aware - if two SessionManager from different namespaces request access to session with same id, repository should give different sessions (unless a special configuration overrides this).

tracking - propagates session information to clients

notifier - may trigger notifications for different session events

configuration - the configuration

classLoader - the class loader to use

Method Detail

getSession

public RepositoryBackedSession getSession(RequestWithSession request,
                                          boolean create,
                                          String forceId)

Builds or retrieves session. If session is found in repository, it is retrieved, if not, and create parameter is set to true, then a new session is created. Session id is generated according to SessionTracking implementation.

In some cases, in servlet engine, request can be forwarded from one web application to another one. In this case, the first web application that received request, is responsible for managing session id, and other web application down the chain will reuse this id.

Parameters:

request - the request being servet

create - true if session should be created

forceId - forces usage of this session id.

Returns:

existing or new session

propagateSession

public void propagateSession(RequestWithSession request,
                             ResponseWithSessionId response)

Propagates the session id to the response. The propagation is done once per request.

Parameters:

request - the current request

response - the current response

delete

public void delete(String sessionId,
                   boolean expired)

Deletes session from repository and performs orderly cleanup. Called when session expires or when application closes

Parameters:

sessionId - the id of the session to delete

expired - true if session is deleted because it has expired

requestFinished

public void requestFinished()

Called when request has been finished. Notifies repository of that fact.

submit

public Future<?> submit(String timer,
                        Runnable task)

Executes task in separate thread. This is used to launch blocking or long-running tasks.

Parameters:

timer - if not null, the time to execute task will be measured and stored under timer with given name

task - the task to run

Returns:

the future for the runnable. Note that runnable has no result.

schedule

public ScheduledFuture<?> schedule(String timer,
                                   Runnable task,
                                   long period)

Schedules the tasks to execute with a ScheduledExecutorService with the specified period.

Parameters:

timer - if not null, the time to execute task will be measured and stored under timer with given name

task - the task to run

period - period between invocations in seconds

Returns:

the scheduled future for the task. Note that runnable has no result.

deleteAsync

public void deleteAsync(String sessionId,
                        boolean expired)

Deletes list of sessions. The deletion might be run in separate thread.

Parameters:

sessionId - session id to delete

expired - true if session is deleted because it has expired

getRepository

public SessionRepository getRepository()

Returns SessionRepository used by this instance.

Returns:

SessionRepository used by this instance.

getNotifier

public SessionNotifier getNotifier()

Returns SessionNotifier used by this instance.

Returns:

SessionNotifier used by this instance.

invokeCommit

public void invokeCommit(RepositoryBackedSession session)

Calls RepositoryBackedSession.Committer for the passed RepositoryBackedSession and measures time of execution.

Parameters:

session - the session to commit

getConfiguration

public SessionConfiguration getConfiguration()

Configuration for this SessionManager

Returns:

the active configuration

getSessionClassLoader

public ClassLoader getSessionClassLoader()

Returns class loader to be used for session objects.

Returns:

the class loader for session objects

getSerializerDeserializer

public SerializerDeserializer getSerializerDeserializer()

Serialiazer/deserializer to use when storing to repository. Serialaizer and deserializers can be configured.

Returns:

serialiazer/deserializer to use

invalidationConflict

public void invalidationConflict(RepositoryBackedSession session,
                                 boolean onExpiry)

Called by RepositoryBackedSession when a conflict occurs during invalidation of session. Conflict may be due to fact that session is stil used.

Parameters:

session - the session to remove

onExpiry - conflict occurred during expiration event

getMetrics

public com.codahale.metrics.MetricRegistry getMetrics()

Retrieves metric registry for this session manager.

Returns:

the metric registry

encodeUrl

public String encodeUrl(RequestWithSession request,
                        String url)

Called to encode URL based on session tracking.

Parameters:

request - the current request

url - the URL to encode

Returns:

encoded URL

close

public void close()

Called to shutdown the session manager and perform needed cleanup.

Specified by:

close in interface Closeable

Specified by:

close in interface AutoCloseable

switchSessionId

public void switchSessionId(RepositoryBackedSession session)

Changes session id of the passed session. Session id can change only once per request.

Parameters:

session - the session whose id needs to change

toString

public String toString()

Overrides:

toString in class Object

remove

public void remove(SessionData sessionData)