class AppServiceImpl implements AppService, ApplicationListener<ConfigChangedEvent> {

    @Transactional(readOnly = true)
    @Override
    public int[] findAppUserIds(int appId) {
        List<Integer> list = userAppRepository.findAppUserIds(appId);
        return ArrayUtils.toPrimitive(list.toArray(ArrayUtils.EMPTY_INTEGER_OBJECT_ARRAY));
    }

}