*/
    protected Map<Pattern, CrawlerClient> clientMap = new LinkedHashMap<>();

    /**
     * Creates a new instance of CrawlerClientFactory.
     */
    public CrawlerClientFactory() {
        // NOP
    }

    /**
     * Initializes the CrawlerClientFactory.
     * Attempts to register itself with a "crawlerClientCreator" component if available.
     */
    @PostConstruct
    public void init() {

     *
     * @param factory the underlying CrawlerClientFactory instance to delegate operations to
     */
    public CrawlerClientFactoryWrapper(final CrawlerClientFactory factory) {
        this.factory = factory;
    }

    /**
     * Returns the parent CrawlerClientFactory.
     * @return The parent CrawlerClientFactory.
     */
    public CrawlerClientFactory getParent() {
        return factory;
    }

    public synchronized void register(final CrawlerClientFactory crawlerClientFactory) {
        clientMap.entrySet().stream().forEach(e -> load(crawlerClientFactory, e.getKey(), e.getValue()));
        clientFactoryList.add(crawlerClientFactory);
        if (clientFactoryList.size() > maxClientFactorySize) {
            clientFactoryList.remove(0);
        }
    }

    /**
     * Registers a client component with a regular expression.

        CrawlerClientFactory crawlerClientFactory = webConfig.initializeClientFactory(() -> new CrawlerClientFactory() {
            public void setInitParameterMap(final Map<String, Object> params) {
                initParamMapSet.set(params);
            }
        });
        assertNotNull(crawlerClientFactory);
        Map<String, Object> initParamMap = initParamMapSet.get();

        return ConfigType.WEB.getConfigId(getId());
    }

    @Override
    public CrawlerClientFactory initializeClientFactory(final Supplier<CrawlerClientFactory> creator) {
        if (crawlerClientFactory != null) {
            return crawlerClientFactory;
        }
        final CrawlerClientFactory factory = creator.get();

        return ConfigType.FILE.getConfigId(getId());
    }

    @Override
    public CrawlerClientFactory initializeClientFactory(final Supplier<CrawlerClientFactory> creator) {
        if (crawlerClientFactory != null) {
            return crawlerClientFactory;
        }
        final CrawlerClientFactory factory = creator.get();

        }
        return handlerScriptMap;
    }

    @Override
    public CrawlerClientFactory initializeClientFactory(final Supplier<CrawlerClientFactory> creator) {
        if (crawlerClientFactory != null) {
            return crawlerClientFactory;
        }
        final CrawlerClientFactory factory = creator.get();

        final Map<String, String> paramMap = getHandlerParameterMap();

        this.intervalController = intervalController;
    }

    /**
     * Returns the crawler client factory.
     * @return The CrawlerClientFactory instance.
     */
    public CrawlerClientFactory getClientFactory() {
        return clientFactory;
    }

    /**
     * Checks if the crawler is running in background mode.

                logger.info("Generating Thumbnail: {}", url);
            }

            final CrawlerClientFactory crawlerClientFactory =
                    config.initializeClientFactory(() -> ComponentUtil.getComponent(CrawlerClientFactory.class));
            final CrawlerClient client = crawlerClientFactory.getClient(url);
            if (client == null) {

├── fess-crawler/              # Core framework
├── fess-crawler-lasta/        # LastaFlute DI integration
└── fess-crawler-opensearch/   # OpenSearch backend
```

### Key Design Patterns

- **Factory**: `CrawlerClientFactory`, `ExtractorFactory` - protocol/format-specific component selection
- **Strategy**: `CrawlerClient`, `Extractor`, `Transformer` - pluggable implementations