Class AbstractSessionCache

All Implemented Interfaces:
SessionCache, Container, Destroyable, Dumpable, Dumpable.DumpableContainer, LifeCycle
Direct Known Subclasses:
DefaultSessionCache, NullSessionCache

@ManagedObject public abstract class AbstractSessionCache extends ContainerLifeCycle implements SessionCache
AbstractSessionCache A base implementation of the SessionCache interface for managing a set of Session objects pertaining to a context in memory. This implementation ensures that multiple requests for the same session id always return the same Session object. It will delay writing out a session to the SessionDataStore until the last request exits the session. If the SessionDataStore supports passivation then the session passivation and activation listeners are called appropriately as the session is written. This implementation also supports evicting idle Session objects. An idle Session is one that is still valid, has not expired, but has not been accessed by a request for a configurable amount of time. An idle session will be first passivated before it is evicted from the cache.
  • Field Details

    • _sessionDataStore

      protected SessionDataStore _sessionDataStore
      The authoritative source of session data
    • _manager

      protected final SessionManager _manager
      The SessionManager related to this SessionCache
    • _context

      protected SessionContext _context
      Information about the context to which this SessionCache pertains
    • _evictionPolicy

      protected int _evictionPolicy
      When, if ever, to evict sessions: never; only when the last request for them finishes; after inactivity time (expressed as secs)
    • _saveOnCreate

      protected boolean _saveOnCreate
      If true, as soon as a new session is created, it will be persisted to the SessionDataStore
    • _saveOnInactiveEviction

      protected boolean _saveOnInactiveEviction
      If true, a session that will be evicted from the cache because it has been inactive too long will be saved before being evicted.
    • _removeUnloadableSessions

      protected boolean _removeUnloadableSessions
      If true, a Session whose data cannot be read will be deleted from the SessionDataStore.
    • _flushOnResponseCommit

      protected boolean _flushOnResponseCommit
      If true, when a response is about to be committed back to the client, a dirty session will be flushed to the session store.
    • _invalidateOnShutdown

      protected boolean _invalidateOnShutdown
      If true, when the server shuts down, all sessions in the cache will be invalidated before being removed.
  • Constructor Details

  • Method Details

    • newSession

      public abstract ManagedSession newSession(SessionData data)
      Create a new Session object from pre-existing session data
      Specified by:
      newSession in interface SessionCache
      Parameters:
      data - the session data
      Returns:
      a new Session object
    • doGet

      protected abstract ManagedSession doGet(String id)
      Get the session matching the key from the cache. Does not load the session.
      Parameters:
      id - session id
      Returns:
      the Session object matching the id
    • doPutIfAbsent

      protected abstract Session doPutIfAbsent(String id, ManagedSession session)
      Put the session into the map if it wasn't already there
      Parameters:
      id - the identity of the session
      session - the session object
      Returns:
      null if the session wasn't already in the map, or the existing entry otherwise
    • doComputeIfAbsent

      protected abstract ManagedSession doComputeIfAbsent(String id, Function<String,ManagedSession> mappingFunction)
      Compute the mappingFunction to create a Session object iff the session with the given id isn't already in the map, otherwise return the existing Session. This method is expected to have precisely the same behaviour as ConcurrentHashMap.computeIfAbsent(K, java.util.function.Function<? super K, ? extends V>)
      Parameters:
      id - the session id
      mappingFunction - the function to load the data for the session
      Returns:
      an existing Session from the cache
    • doReplace

      protected abstract boolean doReplace(String id, ManagedSession oldValue, ManagedSession newValue)
      Replace the mapping from id to oldValue with newValue
      Parameters:
      id - the id
      oldValue - the old value
      newValue - the new value
      Returns:
      true if replacement was done
    • doDelete

      public abstract ManagedSession doDelete(String id)
      Remove the session with this identity from the store
      Parameters:
      id - the id
      Returns:
      Session that was removed or null
    • getSessionManager

      public SessionManager getSessionManager()
      Specified by:
      getSessionManager in interface SessionCache
      Returns:
      the SessionManger
    • initialize

      public void initialize(SessionContext context)
      Specified by:
      initialize in interface SessionCache
      Parameters:
      context - the SessionContext to use for this cache
    • doStart

      protected void doStart() throws Exception
      Description copied from class: ContainerLifeCycle
      Starts the managed lifecycle beans in the order they were added.
      Overrides:
      doStart in class ContainerLifeCycle
      Throws:
      AbstractLifeCycle.StopException - If thrown, the lifecycle will immediately be stopped.
      Exception - If there was a problem starting. Will cause a transition to FAILED state
    • doStop

      protected void doStop() throws Exception
      Description copied from class: ContainerLifeCycle
      Stops the managed lifecycle beans in the reverse order they were added.
      Overrides:
      doStop in class ContainerLifeCycle
      Throws:
      Exception - If there was a problem stopping. Will cause a transition to FAILED state
    • getSessionDataStore

      public SessionDataStore getSessionDataStore()
      Specified by:
      getSessionDataStore in interface SessionCache
      Returns:
      the SessionDataStore or null if there isn't one
    • setSessionDataStore

      public void setSessionDataStore(SessionDataStore sessionStore)
      Description copied from interface: SessionCache
      A SessionDataStore that is the authoritative source of session information.
      Specified by:
      setSessionDataStore in interface SessionCache
      Parameters:
      sessionStore - the SessionDataStore to use
    • getEvictionPolicy

      @ManagedAttribute(value="session eviction policy", readonly=true) public int getEvictionPolicy()
      Specified by:
      getEvictionPolicy in interface SessionCache
      Returns:
      the eviction policy
    • setEvictionPolicy

      public void setEvictionPolicy(int evictionTimeout)
      -1 means we never evict inactive sessions. 0 means we evict a session after the last request for it exits >0 is the number of seconds after which we evict inactive sessions from the cache
      Specified by:
      setEvictionPolicy in interface SessionCache
      Parameters:
      evictionTimeout - -1 is never evict; 0 is evict-on-exit; and any other positive value is the time in seconds that a session can be idle before it can be evicted.
    • isSaveOnCreate

      @ManagedAttribute(value="immediately save new sessions", readonly=true) public boolean isSaveOnCreate()
      Specified by:
      isSaveOnCreate in interface SessionCache
      Returns:
      if true the newly created session will be saved immediately
    • setSaveOnCreate

      public void setSaveOnCreate(boolean saveOnCreate)
      Description copied from interface: SessionCache
      Whether or not a session that is newly created should be immediately saved. If false, a session that is created and invalidated within a single request is never persisted.
      Specified by:
      setSaveOnCreate in interface SessionCache
      Parameters:
      saveOnCreate - true to immediately save the newly created session
    • isRemoveUnloadableSessions

      @ManagedAttribute(value="delete unreadable stored sessions", readonly=true) public boolean isRemoveUnloadableSessions()
      Specified by:
      isRemoveUnloadableSessions in interface SessionCache
      Returns:
      true if sessions that can't be loaded are deleted from the store
    • setRemoveUnloadableSessions

      public void setRemoveUnloadableSessions(boolean removeUnloadableSessions)
      If a session's data cannot be loaded from the store without error, remove it from the persistent store.
      Specified by:
      setRemoveUnloadableSessions in interface SessionCache
      Parameters:
      removeUnloadableSessions - if true unloadable sessions will be removed from session store
    • setFlushOnResponseCommit

      public void setFlushOnResponseCommit(boolean flushOnResponseCommit)
      Description copied from interface: SessionCache
      If true, a dirty session will be written to the SessionDataStore just before a response is returned to the client. This ensures that subsequent requests to either the same node or a different node see the changed session data.
      Specified by:
      setFlushOnResponseCommit in interface SessionCache
    • isFlushOnResponseCommit

      public boolean isFlushOnResponseCommit()
      Specified by:
      isFlushOnResponseCommit in interface SessionCache
      Returns:
      true if dirty sessions should be written before the response is committed.
    • get

      public ManagedSession get(String id) throws Exception
      Get a session object. If the session object is not in this session store, try getting the data for it from a SessionDataStore associated with the session manager. The usage count of the session is incremented.
      Specified by:
      get in interface SessionCache
      Parameters:
      id - the session id
      Returns:
      the Session if one exists, null otherwise
      Throws:
      Exception - if any error occurred
    • getAndEnter

      protected ManagedSession getAndEnter(String id, boolean enter) throws Exception
      Get a session object. If the session object is not in this session store, try getting the data for it from a SessionDataStore associated with the session manager.
      Parameters:
      id - The session to retrieve
      enter - if true, the usage count of the session will be incremented
      Returns:
      the session if it exists, null otherwise
      Throws:
      Exception - if the session cannot be loaded
    • add

      public void add(String id, ManagedSession session) throws Exception
      Add an entirely new session (created by the application calling Request.getSession(true)) to the cache. The usage count of the fresh session is incremented.
      Specified by:
      add in interface SessionCache
      Parameters:
      id - the id
      session - the session
      Throws:
      Exception
    • commit

      public void commit(ManagedSession session) throws Exception
      A response that has accessed this session is about to be returned to the client. Pass the session to the store to persist, so that any changes will be visible to subsequent requests on the same node (if using NullSessionCache), or on other nodes.
      Specified by:
      commit in interface SessionCache
      Throws:
      Exception
    • release

      public void release(ManagedSession session) throws Exception
      Finish using the Session object. This should be called when a request exists the session. Only when the last simultaneous request exists the session will any action be taken. If there is a SessionDataStore write the session data through to it. If the SessionDataStore supports passivation, call the passivate/active listeners. If the evictionPolicy == SessionCache.EVICT_ON_SESSION_EXIT then after we have saved the session, we evict it from the cache.
      Specified by:
      release in interface SessionCache
      Parameters:
      session - the current session object
      Throws:
      Exception - if any error occurred
    • exists

      public boolean exists(String id) throws Exception
      Check to see if a session corresponding to the id exists. This method will first check with the object store. If it doesn't exist in the object store (might be passivated etc), it will check with the data store.
      Specified by:
      exists in interface SessionCache
      Parameters:
      id - the session id
      Returns:
      true if the session exists, false otherwise
      Throws:
      Exception - the Exception
    • contains

      public boolean contains(String id) throws Exception
      Check to see if this cache contains an entry for the session corresponding to the session id.
      Specified by:
      contains in interface SessionCache
      Parameters:
      id - the session id
      Returns:
      true if a Session object matching the id is present in the cache, false otherwise
      Throws:
      Exception - if any error occurred
    • delete

      public ManagedSession delete(String id) throws Exception
      Remove a session object from this store and from any backing store.
      Specified by:
      delete in interface SessionCache
      Parameters:
      id - the session id
      Returns:
      the Session that was removed, null otherwise
      Throws:
      Exception - if any error occurred
    • checkExpiration

      public Set<String> checkExpiration(Set<String> candidates)
      Description copied from interface: SessionCache
      Check a list of session ids that belong to potentially expired sessions. The Session in the cache should be checked, but also the SessionDataStore, as that is the authoritative source of all session information.
      Specified by:
      checkExpiration in interface SessionCache
      Parameters:
      candidates - the session ids to check
      Returns:
      the set of session ids that have actually expired: this can be a superset of the original candidate list.
    • checkInactiveSession

      public void checkInactiveSession(ManagedSession session)
      Check a session for being inactive and thus being able to be evicted, if eviction is enabled.
      Specified by:
      checkInactiveSession in interface SessionCache
      Parameters:
      session - session to check
    • renewSessionId

      public ManagedSession renewSessionId(String oldId, String newId, String oldExtendedId, String newExtendedId) throws Exception
      Description copied from interface: SessionCache
      Change the id of a Session.
      Specified by:
      renewSessionId in interface SessionCache
      Parameters:
      oldId - the current session id
      newId - the new session id
      oldExtendedId - the current extended session id
      newExtendedId - the new extended session id
      Returns:
      the Session after changing its id
      Throws:
      Exception - if any error occurred
    • renewSessionId

      protected void renewSessionId(ManagedSession session, String newId, String newExtendedId) throws Exception
      Swap the id on a session.
      Parameters:
      session - the session for which to do the swap
      newId - the new id
      newExtendedId - the full id plus node id
      Throws:
      Exception - if there was a failure saving the change
    • setSaveOnInactiveEviction

      public void setSaveOnInactiveEviction(boolean saveOnEvict)
      Description copied from interface: SessionCache
      Whether or not a a session that is about to be evicted should be saved before being evicted.
      Specified by:
      setSaveOnInactiveEviction in interface SessionCache
      Parameters:
      saveOnEvict - true if the session should be saved before being evicted
    • setInvalidateOnShutdown

      public void setInvalidateOnShutdown(boolean invalidateOnShutdown)
      Description copied from interface: SessionCache
      If true, all existing sessions in the cache will be invalidated when the server shuts down. Default is false.
      Specified by:
      setInvalidateOnShutdown in interface SessionCache
      Parameters:
      invalidateOnShutdown - true invalidate all sessions in cache on server shutdown
    • isInvalidateOnShutdown

      public boolean isInvalidateOnShutdown()
      Specified by:
      isInvalidateOnShutdown in interface SessionCache
    • isSaveOnInactiveEviction

      @ManagedAttribute(value="save sessions before evicting from cache", readonly=true) public boolean isSaveOnInactiveEviction()
      Whether we should save a session that has been inactive before we boot it from the cache.
      Specified by:
      isSaveOnInactiveEviction in interface SessionCache
      Returns:
      true if an inactive session will be saved before being evicted
    • newSession

      public ManagedSession newSession(String id, long time, long maxInactiveMs)
      Description copied from interface: SessionCache
      Create an entirely new Session.
      Specified by:
      newSession in interface SessionCache
      Parameters:
      id - the unique id associated to the session
      time - the timestamp of the session creation
      maxInactiveMs - the max inactive time in milliseconds
      Returns:
      a new Session
    • toString

      public String toString()
      Overrides:
      toString in class AbstractLifeCycle