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

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

    /**
     * Logger instance for this class.
     */
    protected static final Logger logger = LogManager.getLogger(ThumbnailManager.class);

    /**

        }
        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()) {

<?xml version="1.0" encoding="UTF-8"?>
<!DOCTYPE components PUBLIC "-//DBFLUTE//DTD LastaDi 1.0//EN"
	"http://dbflute.org/meta/lastadi10.dtd">
<components>
	<component name="thumbnailManager" class="org.codelibs.fess.thumbnail.ThumbnailManager">
	</component>
	<component name="htmlThumbnailGenerator" class="org.codelibs.fess.thumbnail.impl.HtmlTagBasedGenerator">
		<property name="name">"htmlThumbnailGenerator"</property>
		<postConstruct name="addCondition">