final FessConfig fessConfig = ComponentUtil.getFessConfig();
        final String thumbnailId = DocumentUtil.getValue(docMap, fessConfig.getIndexFieldId(), String.class);
        final Tuple3<String, String, String> task = new Tuple3<>(getName(), thumbnailId, path);
        if (logger.isDebugEnabled()) {
            logger.debug("Create thumbnail task: {}", task);
        }
        return task;

 */
package org.codelibs.fess.thumbnail.impl;

import java.io.File;

public class EmptyGenerator extends BaseThumbnailGenerator {

    @Override
    public boolean generate(final String thumbnailId, final File outputFile) {
        return false;
    }

    @Override
    public void destroy() {
        // nothing
    }

import java.io.File;
import java.util.Map;

import org.codelibs.core.misc.Tuple3;

public interface ThumbnailGenerator {

    String getName();

    boolean generate(String thumbnailId, File outputFile);

    boolean isTarget(Map<String, Object> docMap);

    boolean isAvailable();

    void destroy();

    Tuple3<String, String, String> createTask(String path, Map<String, Object> docMap);

            systemProperties.reload(options.propertiesPath);
        } else {
            try {
                final File propFile = ComponentUtil.getSystemHelper().createTempFile("thumbnail_", ".properties");
                if (propFile.delete() && logger.isDebugEnabled()) {
                    logger.debug("Deleted a temp file: {}", propFile.getAbsolutePath());
                }