I developed an application using vaadin and quartz scheduler. I have this code :
final ServletContext servletContext = VaadinServlet.getCurrent().getServletContext();
StdSchedulerFactory stdSchedulerFactory = (StdSchedulerFactory) servletContext
.getAttribute(QuartzInitializerListener.QUARTZ_FACTORY_KEY);
final Scheduler scheduler = stdSchedulerFactory.getScheduler();
So I notice that sometimes after the server reboot I have a java.lang.NullPointerException
on this line stdSchedulerFactory.getScheduler()
Can you explain me what happen?