Package com.vaadin.server

Class VaadinSession

  • All Implemented Interfaces:
    Serializable, EventListener, javax.servlet.http.HttpSessionBindingListener
    public class VaadinSession
extends Object
implements javax.servlet.http.HttpSessionBindingListener, Serializable
    Contains everything that Vaadin needs to store for a specific user. This is typically stored in a HttpSession, but others storage mechanisms might also be used.

    Everything inside a VaadinSession should be serializable to ensure compatibility with schemes using serialization for persisting the session data.

    Since:
    7.0.0
    Author:
    Vaadin Ltd
    See Also:
    Serialized Form

    • Field Detail

      • UI_PARAMETER

        public static final String UI_PARAMETER
        The name of the parameter that is by default used in e.g. web.xml to define the name of the default UI class.
        See Also:
        Constant Field Values

      • UI_PRIORITY_PARAMETER

        public static final String UI_PRIORITY_PARAMETER
        The priority of the specified default UI class (defaults to 0)
        See Also:
        Constant Field Values

    • Constructor Detail

      • VaadinSession

        public VaadinSession​(VaadinService service)
        Creates a new VaadinSession tied to a VaadinService.
        Parameters:
        service - the Vaadin service for the new session

    • Method Detail

      • valueBound

        public void valueBound​(javax.servlet.http.HttpSessionBindingEvent arg0)
        Specified by:
        valueBound in interface javax.servlet.http.HttpSessionBindingListener
        See Also:
        HttpSessionBindingListener.valueBound(HttpSessionBindingEvent)

      • valueUnbound

        public void valueUnbound​(javax.servlet.http.HttpSessionBindingEvent event)
        Specified by:
        valueUnbound in interface javax.servlet.http.HttpSessionBindingListener
        See Also:
        HttpSessionBindingListener.valueUnbound(HttpSessionBindingEvent)

      • getCumulativeRequestDuration

        public long getCumulativeRequestDuration()
        Returns:
        The total time spent servicing requests in this session, in milliseconds.

      • setLastRequestDuration

        public void setLastRequestDuration​(long time)
        Sets the time spent servicing the last request in the session and updates the total time spent servicing requests in this session.
        Parameters:
        time - The time spent in the last request, in milliseconds.

      • getLastRequestDuration

        public long getLastRequestDuration()
        Returns:
        The time spent servicing the last request in this session, in milliseconds.

      • setLastRequestTimestamp

        public void setLastRequestTimestamp​(long timestamp)
        Sets the time when the last UIDL request was serviced in this session.
        Parameters:
        timestamp - The time when the last request was handled, in milliseconds since the epoch.

      • getLastRequestTimestamp

        public long getLastRequestTimestamp()
        Returns the time when the last request was serviced in this session.
        Returns:
        The time when the last request was handled, in milliseconds since the epoch.

      • getSession

        public WrappedSession getSession()
        Gets the underlying session to which this service session is currently associated.
        Returns:
        the wrapped session for this context

      • getForSession

        @Deprecated
public static VaadinSession getForSession​(VaadinService service,
                                          WrappedSession underlyingSession)
        Deprecated.
        as of 7.6, call VaadinService.loadSession(WrappedSession) instead
        Loads the VaadinSession for the given service and WrappedSession from the HTTP session.
        Parameters:
        service - The service the VaadinSession is associated with
        underlyingSession - The wrapped HTTP session for the user
        Returns:
        A VaadinSession instance for the service, session combination or null if none was found.

      • getAllSessions

        public static Collection<VaadinSession> getAllSessions​(javax.servlet.http.HttpSession httpSession)
        Retrieves all VaadinSessions which are stored in the given HTTP session
        Parameters:
        httpSession - the HTTP session
        Returns:
        the found VaadinSessions
        Since:
        7.2

      • getConfiguration

        public DeploymentConfiguration getConfiguration()
        Gets the configuration for this session
        Returns:
        the deployment configuration

      • getLocale

        public Locale getLocale()
        Gets the default locale for this session. By default this is the preferred locale of the user using the session. In most cases it is read from the browser defaults.
        Returns:
        the locale of this session.

      • setLocale

        public void setLocale​(Locale locale)
        Sets the default locale for this session. By default this is the preferred locale of the user using the application. In most cases it is read from the browser defaults.
        Parameters:
        locale - the Locale object.

      • getErrorHandler

        public ErrorHandler getErrorHandler()
        Gets the session's error handler.
        Returns:
        the current error handler

      • setErrorHandler

        public void setErrorHandler​(ErrorHandler errorHandler)
        Sets the session error handler.
        Parameters:
        errorHandler -

      • addRequestHandler

        public void addRequestHandler​(RequestHandler handler)
        Adds a request handler to this session. Request handlers can be added to provide responses to requests that are not handled by the default functionality of the framework.

        Handlers are called in reverse order of addition, so the most recently added handler will be called first.

        Parameters:
        handler - the request handler to add
        Since:
        7.0
        See Also:
        removeRequestHandler(RequestHandler)

      • removeRequestHandler

        public void removeRequestHandler​(RequestHandler handler)
        Removes a request handler from the session.
        Parameters:
        handler - the request handler to remove
        Since:
        7.0

      • getRequestHandlers

        public Collection<RequestHandler> getRequestHandlers()
        Gets the request handlers that are registered to the session. The iteration order of the returned collection is the same as the order in which the request handlers will be invoked when a request is handled.
        Returns:
        a collection of request handlers, with the iteration order according to the order they would be invoked
        Since:
        7.0
        See Also:
        addRequestHandler(RequestHandler), removeRequestHandler(RequestHandler)

      • getCurrent

        public static VaadinSession getCurrent()
        Gets the currently used session. The current session is automatically defined when processing requests to the server and in threads started at a point when the current session is defined (see InheritableThreadLocal). In other cases, (e.g. from background threads started in some other way), the current session is not automatically defined.

        The session is stored using a weak reference to avoid leaking memory in case it is not explicitly cleared.

        Returns:
        the current session instance if available, otherwise null
        Since:
        7.0
        See Also:
        setCurrent(VaadinSession)

      • setCurrent

        public static void setCurrent​(VaadinSession session)
        Sets the thread local for the current session. This method is used by the framework to set the current session whenever a new request is processed and it is cleared when the request has been processed.

        The application developer can also use this method to define the current session outside the normal request handling and treads started from request handling threads, e.g. when initiating custom background threads.

        The session is stored using a weak reference to avoid leaking memory in case it is not explicitly cleared.

        Parameters:
        session - the session to set as current
        Since:
        7.0
        See Also:
        getCurrent(), ThreadLocal

      • getUIs

        public Collection<UI> getUIs()
        Gets all the UIs of this session. This includes UIs that have been requested but not yet initialized. UIs that receive no heartbeat requests from the client are eventually removed from the session.
        Returns:
        a collection of UIs belonging to this application
        Since:
        7.0

      • createConnectorId

        @Deprecated
public String createConnectorId​(ClientConnector connector)
        Deprecated.
        As of 7.0. Will likely change or be removed in a future version
        Generate an id for the given Connector. Connectors must not call this method more than once, the first time they need an id.
        Parameters:
        connector - A connector that has not yet been assigned an id.
        Returns:
        A new id for the connector

      • getUIById

        public UI getUIById​(int uiId)
        Returns a UI with the given id.

        This is meant for framework internal use.

        Parameters:
        uiId - The UI id
        Returns:
        The UI with the given id or null if not found

      • hasLock

        public boolean hasLock()
        Checks if the current thread has exclusive access to this VaadinSession
        Returns:
        true if the thread has exclusive access, false otherwise
        Since:
        7.1

      • hasLock

        protected static boolean hasLock​(VaadinService service,
                                 WrappedSession session)
        Checks if the current thread has exclusive access to the given WrappedSession.
        Returns:
        true if this thread has exclusive access, false otherwise
        Since:
        7.6

      • modifyBootstrapResponse

        @Deprecated
public void modifyBootstrapResponse​(BootstrapResponse response)
        Deprecated.
        As of 7.0. Will likely change or be removed in a future version
        Fires a bootstrap event to all registered listeners. There are currently two supported events, both inheriting from BootstrapResponse: BootstrapFragmentResponse and BootstrapPageResponse.
        Parameters:
        response - the bootstrap response event for which listeners should be fired

      • removeUI

        public void removeUI​(UI ui)
        Called by the framework to remove an UI instance from the session because it has been closed.
        Parameters:
        ui - the UI to remove

      • getGlobalResourceHandler

        public GlobalResourceHandler getGlobalResourceHandler​(boolean createOnDemand)
        Gets this session's global resource handler that takes care of serving connector resources that are not served by any single connector because e.g. because they are served with strong caching or because of legacy reasons.
        Parameters:
        createOnDemand - true if a resource handler should be initialized if there is no handler associated with this application, false if null should be returned if there is no registered handler.
        Returns:
        this session's global resource handler, or null if there is no handler and the createOnDemand parameter is false.
        Since:
        7.0.0

      • getLockInstance

        public Lock getLockInstance()
        Gets the Lock instance that is used for protecting the data of this session from concurrent access.

        The Lock can be used to gain more control than what is available only using lock() and unlock(). The returned instance is not guaranteed to support any other features of the Lock interface than Lock.lock() and Lock.unlock().

        Returns:
        the Lock that is used for synchronization, never null
        See Also:
        lock(), Lock

      • lock

        public void lock()
        Locks this session to protect its data from concurrent access. Accessing the UI state from outside the normal request handling should always lock the session and unlock it when done. The preferred way to ensure locking is done correctly is to wrap your code using UI.access(Runnable) (or access(Runnable) if you are only touching the session and not any UI), e.g.: 
         myUI.access(new Runnable() {
     @Override
     public void run() {
         // Here it is safe to update the UI.
         // UI.getCurrent can also be used
         myUI.getContent().setCaption("Changed safely");
     }
 });
        If you for whatever reason want to do locking manually, you should do it like: 
         session.lock();
 try {
     doSomething();
 } finally {
     session.unlock();
 }
        This method will block until the lock can be retrieved.

        getLockInstance() can be used if more control over the locking is required.

        See Also:
        unlock(), getLockInstance(), hasLock()

      • unlock

        public void unlock()
        Unlocks this session. This method should always be used in a finally block after lock() to ensure that the lock is always released.

        For UIs in this session that have its push mode set to automatic, pending changes will be pushed to their respective clients.

        See Also:
        lock(), UI.push()

      • setAttribute

        public void setAttribute​(String name,
                         Object value)
        Stores a value in this service session. This can be used to associate data with the current user so that it can be retrieved at a later point from some other part of the application. Setting the value to null clears the stored value.
        Parameters:
        name - the name to associate the value with, can not be null
        value - the value to associate with the name, or null to remove a previous association.
        See Also:
        getAttribute(String)

      • setAttribute

        public <T> void setAttribute​(Class<T> type,
                             T value)
        Stores a value in this service session. This can be used to associate data with the current user so that it can be retrieved at a later point from some other part of the application. Setting the value to null clears the stored value.

        The fully qualified name of the type is used as the name when storing the value. The outcome of calling this method is thus the same as if calling

        setAttribute(type.getName(), value);

        Parameters:
        type - the type that the stored value represents, can not be null
        value - the value to associate with the type, or null to remove a previous association.
        See Also:
        getAttribute(Class), setAttribute(String, Object)

      • getAttribute

        public Object getAttribute​(String name)
        Gets a stored attribute value. If a value has been stored for the session, that value is returned. If no value is stored for the name, null is returned.
        Parameters:
        name - the name of the value to get, can not be null.
        Returns:
        the value, or null if no value has been stored or if it has been set to null.
        See Also:
        setAttribute(String, Object)

      • getAttribute

        public <T> T getAttribute​(Class<T> type)
        Gets a stored attribute value. If a value has been stored for the session, that value is returned. If no value is stored for the name, null is returned.

        The fully qualified name of the type is used as the name when getting the value. The outcome of calling this method is thus the same as if calling

        getAttribute(type.getName());

        Parameters:
        type - the type of the value to get, can not be null.
        Returns:
        the value, or null if no value has been stored or if it has been set to null.
        See Also:
        setAttribute(Class, Object), getAttribute(String)

      • getNextUIid

        public int getNextUIid()
        Creates a new unique id for a UI.
        Returns:
        a unique UI id

      • addUI

        public void addUI​(UI ui)
        Adds an initialized UI to this session.
        Parameters:
        ui - the initialized UI to add.

      • addUIProvider

        public void addUIProvider​(UIProvider uiProvider)
        Adds a UI provider to this session. The UI provider is inserted as the first UI provider with priority 0. UI providers with higher priority will take precedence.
        Parameters:
        uiProvider - the UI provider that should be added

      • addUIProvider

        public void addUIProvider​(UIProvider uiProvider,
                          int priority)
        Adds a UI provider to this session with a persistent priority value. The order of insertion is FILO; the new UI provider is inserted into the list before other UI providers with the same priority level.
        Parameters:
        uiProvider - the UI provider that should be added
        priority - the priority value. Higher priority value means that the UI provider gets put earlier in the list of providers. Default priority is 0.
        Since:
        7.7.41

      • removeUIProvider

        public void removeUIProvider​(UIProvider uiProvider)
        Removes a UI provider association from this session.
        Parameters:
        uiProvider - the UI provider that should be removed

      • getUIProviders

        public List<UIProvider> getUIProviders()
        Gets the UI providers configured for this session.
        Returns:
        an unmodifiable list of UI providers

      • getUIProviderPriority

        public int getUIProviderPriority​(UIProvider provider)
        Get the priority of a specific, already added UI provider. If the UI provider has not been added to this Session, returns Integer.MIN_VALUE.
        Parameters:
        provider - a UIProvider instance
        Returns:
        priority of the UI provider, 0 if the provider was added with no set priority or Integer.MIN_INT if the UI provider has not been added to this Session.
        Since:
        7.7.41

      • setUIProviderPriority

        public void setUIProviderPriority​(UIProvider provider,
                                  int priority)
                           throws NoSuchElementException
        Set the priority of a specific, already added UI provider. If the UI provider has not been added to this Session, throws a NoSuchElementException.

        Please note, that this will cause an immediate re-sorting of all added UIProvider instances. The sorting is guaranteed to be stable.

        Parameters:
        provider - a UIProvider instance
        priority - desired new priority
        Throws:
        NoSuchElementException - if the UI provider is not a part of this Session.
        Since:
        7.7.41

      • close

        public void close()
        Sets this session to be closed and all UI state to be discarded at the end of the current request, or at the end of the next request if there is no ongoing one.

        After the session has been discarded, any UIs that have been left open will give a Session Expired error and a new session will be created for serving new UIs.

        To avoid causing out of sync errors, you should typically redirect to some other page using Page.setLocation(String) to make the browser unload the invalidated UI.

        See Also:
        SystemMessages.getSessionExpiredCaption()

      • isClosing

        @Deprecated
public boolean isClosing()
        Deprecated.
        As of 7.2, use getState() != State.OPEN instead.
        Returns whether this session is marked to be closed. Note that this method also returns true if the session is actually already closed.
        Returns:
        true if this session is marked to be closed, false otherwise
        See Also:
        close()

      • getState

        public VaadinSession.State getState()
        Returns the lifecycle state of this session.
        Returns:
        the current state
        Since:
        7.2

      • setState

        protected void setState​(VaadinSession.State state)
        Sets the lifecycle state of this session. The allowed transitions are OPEN to CLOSING and CLOSING to CLOSED.
        Parameters:
        state - the new state
        Since:
        7.2

      • accessSynchronously

        public void accessSynchronously​(Runnable runnable)
        Locks this session and runs the provided Runnable right away.

        It is generally recommended to use access(Runnable) instead of this method for accessing a session from a different thread as access(Runnable) can be used while holding the lock of another session. To avoid causing deadlocks, this methods throws an exception if it is detected than another session is also locked by the current thread.

        This method behaves differently than access(Runnable) in some situations:

        Parameters:
        runnable - the runnable which accesses the session
        Throws:
        IllegalStateException - if the current thread holds the lock for another session
        Since:
        7.1
        See Also:
        lock(), getCurrent(), access(Runnable), UI.accessSynchronously(Runnable)

      • access

        public Future<Void> access​(Runnable runnable)
        Provides exclusive access to this session from outside a request handling thread.

        The given runnable is executed while holding the session lock to ensure exclusive access to this session. If this session is not locked, the lock will be acquired and the runnable is run right away. If this session is currently locked, the runnable will be run before that lock is released.

        RPC handlers for components inside this session do not need to use this method as the session is automatically locked by the framework during RPC handling.

        Please note that the runnable might be invoked on a different thread or later on the current thread, which means that custom thread locals might not have the expected values when the runnable is executed. Inheritable values in CurrentInstance will have the same values as when this method was invoked. getCurrent() and VaadinService.getCurrent() are set according to this session before executing the runnable. Non-inheritable CurrentInstance values including VaadinService.getCurrentRequest() and VaadinService.getCurrentResponse() will not be defined.

        The returned future can be used to check for task completion and to cancel the task. To help avoiding deadlocks, Future.get() throws an exception if it is detected that the current thread holds the lock for some other session.

        Parameters:
        runnable - the runnable which accesses the session
        Returns:
        a future that can be used to check for task completion and to cancel the task
        Since:
        7.1
        See Also:
        lock(), getCurrent(), accessSynchronously(Runnable), UI.access(Runnable)

      • getPendingAccessQueue

        public Queue<VaadinSession.FutureAccess> getPendingAccessQueue()
        Gets the queue of tasks submitted using access(Runnable). It is safe to call this method and access the returned queue without holding the session lock.
        Returns:
        the queue of pending access tasks
        Since:
        7.1

      • getCsrfToken

        public String getCsrfToken()
        Gets the CSRF token (aka double submit cookie) that is used to protect against Cross Site Request Forgery attacks.
        Returns:
        the csrf token string
        Since:
        7.1

      • getPushId

        public String getPushId()
        Gets the push connection identifier for this session. Used when establishing a push connection with the client.
        Returns:
        the push connection identifier string
        Since:
        7.7.11

      • getUIByEmbedId

        public UI getUIByEmbedId​(String embedId)
        Finds the UI with the corresponding embed id.
        Parameters:
        embedId - the embed id
        Returns:
        the UI with the corresponding embed id, or null if no UI is found
        Since:
        7.2
        See Also:
        UI.getEmbedId()

      • refreshTransients

        public void refreshTransients​(WrappedSession wrappedSession,
                              VaadinService vaadinService)
        Refreshes the transient fields of the session to ensure they are up to date.

        Called internally by the framework.

        Parameters:
        wrappedSession - the session this VaadinSession is stored in
        vaadinService - the service associated with this VaadinSession
        Since:
        7.6