}
    }

    /**
     * Preprocesses a URI to ensure it's in the correct format for file system access.
     *
     * @param uri the URI to preprocess
     * @return the preprocessed URI
     * @throws CrawlerSystemException if the URI is empty
     */
    protected String preprocessUri(final String uri) {
        if (StringUtil.isEmpty(uri)) {
            throw new CrawlerSystemException("The uri is empty.");

    }

    /**
     * Preprocesses the URI before processing the request.
     *
     * @param uri the URI to preprocess
     * @return the preprocessed URI
     * @throws CrawlerSystemException if the URI is empty
     */
    protected String preprocessUri(final String uri) {
        if (StringUtil.isEmpty(uri)) {
            throw new CrawlerSystemException("The uri is empty.");
        }

        return uri;

    @Override
    public ResponseData doGet(final String uri) {
        return processRequest(uri, true);
    }

    /**
     * Processes an FTP request to retrieve data from the specified URI.
     * This method handles the complete FTP request lifecycle including timeout management,
     * connection setup, and data retrieval.
     *
     * @param uri The URI to retrieve data from

        if (StringUtil.isBlank(url) || url.startsWith("file:")) {
            // not target
            return;
        }

        try {
            final URI uri = new URI(url);
            final String host = uri.getHost();
            if (host == null) {
                return;
            }
            final AtomicLong lastTime = lastTimes.putIfAbsent(host, new AtomicLong(SystemUtil.currentTimeMillis()));

        }

        try {
            final int pos = path.indexOf('/', 6);
            final URI uri = new URI(pos == -1 ? path : path.substring(0, pos));
            if (!"ftp".equals(uri.getScheme()) || (StringUtil.isNotBlank(server) && !server.equals(uri.getHost()))) {
                return false;
            }
            int p = uri.getPort();
            if (p == -1) {
                p = 21;
            }

    }

    /**
     * Preprocesses the URI before processing the request.
     *
     * @param uri the URI to preprocess
     * @return the preprocessed URI
     * @throws CrawlerSystemException if the URI is empty
     */
    protected String preprocessUri(final String uri) {
        if (StringUtil.isEmpty(uri)) {
            throw new CrawlerSystemException("The uri is empty.");
        }

        return uri;

        return null;
    }

    /**
     * Preprocesses a URI to ensure it has the correct storage protocol prefix.
     * @param uri the URI to preprocess
     * @return the preprocessed URI with storage:// prefix
     * @throws CrawlerSystemException if the URI is empty
     */
    protected String preprocessUri(final String uri) {
        if (StringUtil.isEmpty(uri)) {
            throw new CrawlerSystemException("The uri is empty.");

import jakarta.validation.ConstraintDefinitionException;
import jakarta.validation.ConstraintValidator;
import jakarta.validation.ConstraintValidatorContext;

/**
 * Validator implementation for URI type constraints.
 * This validator checks URI strings against specified protocol types.
 */
public class UriTypeValidator implements ConstraintValidator<UriType, String> {

    /**
     * Default constructor for UriTypeValidator.
     */

            // base href
            final String baseHref = getBaseHref(document);
            URI uri;
            try {
                uri = new URI(baseHref == null ? responseData.getUrl() : baseHref);
            } catch (final Exception e) {
                uri = new URI(responseData.getUrl());
            }
            final URL url = uri.toURL();
            getChildUrlRules(responseData, resultData).forEach(entry -> {

    }

    /**
     * SAX event handler called when an XML start element is encountered.
     * Processes collection definitions and tracks the element hierarchy.
     *
     * @param uri the namespace URI, or empty string if none
     * @param localName the local name without prefix, or empty string if namespace processing is not performed