Class HeartbeatHandler

Constructor Detail

• HeartbeatHandler

  public HeartbeatHandler()

Method Detail

• canHandleRequest

  protected boolean canHandleRequest​(VaadinRequest request)

  Description copied from class: SynchronizedRequestHandler

  Check whether a request may be handled by this handler. This can be used as an optimization to avoid locking the session just to investigate some method property. The default implementation just returns true which means that all requests will be handled by calling SynchronizedRequestHandler.synchronizedHandleRequest(VaadinSession, VaadinRequest, VaadinResponse) with the session locked.

  Overrides:

  canHandleRequest in class SynchronizedRequestHandler

  Parameters:

  request - the request to handle

  Returns:

  true if the request handling should continue once the session has been locked; false if there's no need to lock the session since the request would still not be handled.

• synchronizedHandleRequest

  public boolean synchronizedHandleRequest​(VaadinSession session,
                                           VaadinRequest request,
                                           VaadinResponse response)
                                    throws IOException

  Handles a heartbeat request for the given session. Reads the GET parameter named ApplicationConstants.UI_ID_PARAMETER to identify the UI. If the UI is found in the session, sets it heartbeat timestamp to the current time. Otherwise, writes a HTTP Not Found error to the response.

  Specified by:

  synchronizedHandleRequest in class SynchronizedRequestHandler

  Parameters:

  session - The session for the request

  request - The request to handle

  response - The response object to which a response can be written.

  Returns:

  true if a response has been written and no further request handlers should be called, otherwise false

  Throws:

  IOException - If an IO error occurred

  See Also:

  SynchronizedRequestHandler.handleRequest(VaadinSession, VaadinRequest, VaadinResponse)

• handleSessionExpired

  public boolean handleSessionExpired​(VaadinRequest request,
                                      VaadinResponse response)
                               throws IOException

  Description copied from interface: SessionExpiredHandler

  Called when the a session expiration has occurred and a notification needs to be sent to the user. If a response is written, this method should return true to indicate that no more SessionExpiredHandler handlers should be invoked for the request.

  Specified by:

  handleSessionExpired in interface SessionExpiredHandler

  Parameters:

  request - The request to handle

  response - The response object to which a response can be written.

  Returns:

  true if a response has been written and no further request handlers should be called, otherwise false

  Throws:

  IOException - If an IO error occurred