public class SomeItemEventSubscriber implements EventSubscriber {
private final Set<String> subscribedEventTypes = ImmutableSet.of(EventSubscriber.ALL_EVENT_TYPES);

    @Override
    public Set<String> getSubscribedEventTypes() {
        System.out.println("============> SomeItemEventSubscriber getSubscribedEventTypes");
        return subscribedEventTypes;
    }

    @Override
    public EventFilter getEventFilter() {
        System.out.println("============> SomeItemEventSubscriber getEventFilter");
        return null;
    }

    @Override
    public void receive(Event event) {
        System.out.println("============> SomeItemEventSubscriber receive");
    }

}

<scr:component xmlns:scr="http://www.osgi.org/xmlns/scr/v1.1.0" immediate="true" name="com.test.notification.SomeItemEventSubscriber">
   <implementation class="com.test.notification.SomeItemEventSubscriber"/>
    <service>
      <provide interface="org.eclipse.smarthome.core.events.EventSubscriber"/>
   </service>
</scr:component>