<property name="lifeCycleURI" value="platform:/plugin/<plug-in-id>/<path-to-handler-class>" />

public class ApplicationLifecycleHandler {
    @PostContextCreate
    public void startup(IEclipseContext context) {
       // do initialization 
    }
}

	@PostContextCreate
	public void postContextCreate(final IEventBroker eventBroker, etc .. ) {

		// 
		eventBroker.subscribe(UIEvents.UILifeCycle.APP_STARTUP_COMPLETE,
				new EventHandler() {
					@Override
					public void handleEvent(Event event) {
						// Your code executed at startup,
						// after application startup is completed
					}
				});
		
	}