AutowiredCollectionNotificationManager.java

@Service
public class NotificationManager {
    @Autowired
    private List<NotificationService> notificationServices;

    public void sendNotifications(String message, String recipient) {
        for (NotificationService service : notificationServices) {
            service.sendNotification(message, recipient);
        }
    }

    public List<String> getAvailableNotificationServices() {
        return notificationServices.stream()
                                   .map(NotificationService::getServiceName)
                                   .collect(Collectors.toList());
    }
}