final FessConfig fessConfig = ComponentUtil.getFessConfig();
        final SystemHelper systemHelper = ComponentUtil.getSystemHelper();
        final String[] targets = fessConfig.getThumbnailGeneratorTargetsAsArray();
        final List<ThumbnailQueue> list = new ArrayList<>();
        taskList.stream().filter(entity -> entity != null).forEach(task -> {
            for (final String target : targets) {