E - the specific ApplicationEvent subclass to listen to
public interface ApplicationListener<E extends ApplicationEvent> extends EventListener
for the Observer design pattern.
As of Spring 3.0, an ApplicationListener can generically declare the event type that it is interested in. When registered with a Spring ApplicationContext, events will be filtered accordingly, with the listener getting invoked for matching event objects only.
void onApplicationEvent(E event)
event - the event to respond to