import jakarta.annotation.PostConstruct;
import jakarta.annotation.PreDestroy;

public class ThumbnailManager {
    private static final String NOIMAGE_FILE_SUFFIX = ".txt";

    protected static final String THUMBNAILS_DIR_NAME = "thumbnails";

    private static final Logger logger = LogManager.getLogger(ThumbnailManager.class);

    protected File baseDir;

        }
        try {
            if (fessConfig.isThumbnailCrawlerEnabled()) {
                final ThumbnailManager thumbnailManager = ComponentUtil.getThumbnailManager();
                final String thumbnailField = fessConfig.getIndexFieldThumbnail();
                docList.stream().forEach(doc -> {
                    if (!thumbnailManager.offer(doc)) {
                        if (logger.isDebugEnabled()) {