private boolean generateCalled = false;
        private boolean destroyCalled = false;

        @Override
        public boolean generate(String thumbnailId, File outputFile) {
            generateCalled = true;
            return true;
        }

        @Override
        public void destroy() {
            destroyCalled = true;
        }

        boolean generateCalled = false;

        @Override
        public String getName() {
            return "testGenerator";
        }

        @Override
        public boolean generate(String thumbnailId, File outputFile) {
            generateCalled = true;
            return generateResult;
        }

        @Override
        public boolean isAvailable() {
            return available;
        }

  check_command convert
  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"

    /**
     * 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.
         */

     * 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.

/**
 * 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";

    /**

import org.codelibs.fess.util.SystemUtil;

import jakarta.servlet.ServletContext;

/**
 * Job class for generating thumbnails for documents in the search engine.
 * This job executes the ThumbnailGenerator process as a separate JVM process
 * to create thumbnail images for supported document types.
 */
public class GenerateThumbnailJob extends ExecJob {
    /** Logger for this class. */

/src/main/webapp/WEB-INF/site/
/src/main/webapp/WEB-INF/plugin/*
!/src/main/webapp/WEB-INF/plugin/.keep
/src/main/webapp/WEB-INF/env/crawler/lib/
/src/main/webapp/WEB-INF/env/suggest/lib/
/src/main/webapp/WEB-INF/env/thumbnail/lib/
/src/main/webapp/WEB-INF/thumbnails/
/src/main/webapp/jar/
/dbflute_fess/extlib/*
/dbflute_fess/log/*.log
/dbflute_h2/log/*.log
/dbflute_mysql/log/*.log
/dbflute_oracle/log/*.log
/src/main/webapp/WEB-INF/conf/*.properties

    }

    /**
     * Gets the path to thumbnail files directory.
     *
     * @param names the path components to append to the thumbnails directory
     * @return the Path object pointing to the thumbnails directory
     */
    public static Path getThumbnailPath(final String... names) {
        return getPath("WEB-INF/", "thumbnails", names);
    }

    /**

     */
    @Size(max = 10)
    public String loginLink;

    /**
     * Enable or disable thumbnail generation for documents.
     * When enabled, thumbnails are generated for supported file types.
     */
    @Size(max = 10)
    public String thumbnail;

    /**
     * Types of crawling failures to ignore during crawling operations.