/**
* Find the UI for the atmosphere resource, lock it and invoke the callback.
*
* @param resource the atmosphere resource for the current request
* @param callback the push callback to call when a UI is found and locked
*/
private void callWithUi(final AtmosphereResource resource, final PushEventCallback callback) {
AtmosphereRequest req = resource.getRequest();
VaadinServletRequest vaadinRequest = new VaadinServletRequest(req, service);
VaadinSession session = null;
service.requestStart(vaadinRequest, null);
try {
try {
session = service.findVaadinSession(vaadinRequest);
} catch (ServiceException e) {
getLogger().log(Level.SEVERE, "Could not get session. This should never happen", e);
} catch (SessionExpiredException e) {
SystemMessages msg =
service.getSystemMessages(
ServletPortletHelper.findLocale(null, null, vaadinRequest), vaadinRequest);
try {
resource
.getResponse()
.getWriter()
.write(
VaadinService.createCriticalNotificationJSON(
msg.getSessionExpiredCaption(),
msg.getSessionExpiredMessage(),
null,
msg.getSessionExpiredURL()));
} catch (IOException e1) {
getLogger().log(Level.WARNING, "Failed to notify client about unavailable session", e);
}
return;
}
session.lock();
try {
VaadinSession.setCurrent(session);
// Sets UI.currentInstance
final UI ui = service.findUI(vaadinRequest);
if (ui == null) {
// This a request through an already open push connection to
// a UI which no longer exists.
resource
.getResponse()
.getWriter()
.write(UidlRequestHandler.getUINotFoundErrorJSON(service, vaadinRequest));
// End the connection
resource.resume();
return;
}
callback.run(resource, ui);
} catch (IOException e) {
getLogger().log(Level.INFO, "An error occured while writing a push response", e);
} finally {
session.unlock();
}
} finally {
service.requestEnd(vaadinRequest, null, session);
}
}
/**
* Sends a refresh message to the given atmosphere resource. Uses an AtmosphereResource instead of
* an AtmospherePushConnection even though it might be possible to look up the
* AtmospherePushConnection from the UI to ensure border cases work correctly, especially when
* there temporarily are two push connections which try to use the same UI. Using the
* AtmosphereResource directly guarantees the message goes to the correct recipient.
*
* @param resource The atmosphere resource to send refresh to
*/
private static void sendRefreshAndDisconnect(AtmosphereResource resource) throws IOException {
AtmospherePushConnection connection = new AtmospherePushConnection(null);
connection.connect(resource);
connection.sendMessage(VaadinService.createCriticalNotificationJSON(null, null, null, null));
connection.disconnect();
}