* @param outputFile the file where the generated thumbnail will be saved
     * @return true if the thumbnail was successfully generated, false otherwise
     */
    @Override
    public boolean generate(final String thumbnailId, final File outputFile) {
        if (logger.isDebugEnabled()) {
            logger.debug("Generate Thumbnail: {}", thumbnailId);
        }

    }

    /**
     * Generates a thumbnail for the given ID and saves it to the output file.
     * @param thumbnailId The ID of the thumbnail to generate.
     * @param outputFile The file where the thumbnail will be saved.
     * @return True if thumbnail generation was successful, false otherwise.
     */
    @Override
    public boolean generate(final String thumbnailId, final File outputFile) {

    }

    /**
     * Generates a thumbnail for the specified ID and output file.
     * This implementation always returns false, indicating no thumbnail was generated.
     *
     * @param thumbnailId the ID of the thumbnail to generate
     * @param outputFile the output file where the thumbnail should be saved
     * @return false always, as this generator does not create thumbnails
     */
    @Override

    String getName();

    /**
     * Generates a thumbnail for the given thumbnail ID and saves it to the output file.
     *
     * @param thumbnailId the unique identifier for the thumbnail
     * @param outputFile the file where the generated thumbnail will be saved
     * @return true if the thumbnail was successfully generated, false otherwise
     */
    boolean generate(String thumbnailId, File outputFile);

    /**

        }
        return value;
    }

    /**
     * Updates the thumbnail field in the search index.
     * @param thumbnailId The thumbnail ID.
     * @param value The thumbnail value to update.
     */
    protected void updateThumbnailField(final String thumbnailId, final String value) {
        // TODO bulk
        final FessConfig fessConfig = ComponentUtil.getFessConfig();

            "keyword", 0, 0, null, null, false, null, null, null, null, null, false);
    protected final ColumnInfo _columnThumbnailId = cci("thumbnail_id", "thumbnail_id", null, null, String.class, "thumbnailId", null,
            false, false, false, "keyword", 0, 0, null, null, false, null, null, null, null, null, false);

    public ColumnInfo columnCreatedBy() {
        return _columnCreatedBy;

    exit 1
  fi
  check_command pdftoppm
  check_command unoconv
  tmp_pdf_file=/tmp/thumbnail.$$.pdf
  unoconv -e PageRange=1-1 -o ${tmp_pdf_file} -f pdf "${target_file}"
  if [[ ! -f ${tmp_pdf_file} ]] ; then
    echo "unoconv does not work."
    exit 1
  fi
  tmp_png_prefix=/tmp/thumbnail.png.$$
  pdftoppm -png -singlefile ${tmp_pdf_file} ${tmp_png_prefix}
  tmp_png_file="${tmp_png_prefix}.png"

     * Creates a new instance of the thumbnail purging job with default expiry time (30 days).
     */
    public PurgeThumbnailJob() {
        // Default constructor
    }

    /** Expiration time for thumbnails in milliseconds (default: 30 days) */
    private long expiry = 30 * 24 * 60 * 60 * 1000L;

    /**
     * Executes the thumbnail purging job.

    /**
     * Command-line options for the thumbnail generator.
     */
    protected static class Options {
        /**
         * Session ID for filtering thumbnail generation.
         */
        @Option(name = "-s", aliases = "--sessionId", metaVar = "sessionId", usage = "Session ID")
        protected String sessionId;

        /**
         * Name identifier for the thumbnail generation task.
         */

/**
 * Manager class for handling thumbnail generation and management.
 * Provides functionality to generate, cache, and serve thumbnail images for documents.
 */
public class ThumbnailManager {
    private static final String NOIMAGE_FILE_SUFFIX = ".txt";

    /**
     * Default directory name for thumbnails.
     */
    protected static final String THUMBNAILS_DIR_NAME = "thumbnails";

    /**