*/
    public String normalize(final String enc) {
        if (StringUtil.isBlank(enc)) {
            return defaultEncoding;
        }

        final String newEnc = encodingMap.get(toLowerCase(enc));
        if (StringUtil.isBlank(newEnc)) {
            return enc;
        }
        return newEnc;
    }

    /**

     * @throws CrawlerSystemException if the MIME type is blank or maxLength is negative
     */
    public void addMaxLength(final String mimeType, final long maxLength) {
        if (StringUtil.isBlank(mimeType)) {
            throw new CrawlerSystemException("MIME type is a blank.");
        }
        if (maxLength < 0) {
            throw new CrawlerSystemException("The value of maxLength is invalid.");
        }

     *
     * @param key   the key of the feature
     * @param value the value of the feature
     */
    public void addFeature(final String key, final String value) {
        if (StringUtil.isBlank(key) || StringUtil.isBlank(value)) {
            throw new CrawlerSystemException("key or value is null.");
        }

        featureMap.put(key, value);
    }

    /**
     * Adds a property to the extractor.

                    } finally {
                        CloseableUtil.closeQuietly(in);
                    }
                }, contentEncoding, normalizeText);
                if (StringUtil.isBlank(content)) {
                    if (resourceName != null) {
                        if (logger.isDebugEnabled()) {
                            logger.debug("retry without a resource name: {}", resourceName);

     * @param regex The regular expression to match URLs.
     * @param client The CrawlerClient instance.
     */
    public void addClient(final String regex, final CrawlerClient client) {
        if (StringUtil.isBlank(regex)) {
            throw new CrawlerSystemException("A regular expression is null.");
        }
        if (client == null) {
            throw new CrawlerSystemException("CrawlerClient is null.");
        }

     * @param enc the character encoding to use
     * @return the encoded URL
     */
    protected String encodeUrl(final String url, final String enc) {
        if (StringUtil.isBlank(url) || StringUtil.isBlank(enc)) {
            return url;
        }

        final StringBuilder buf = new StringBuilder(url.length() + 100);
        for (final char c : url.toCharArray()) {

            if ("field".equals(qName)) {
                fieldName = attributes.getValue("name");
                if (StringUtil.isBlank(fieldName)) {
                    fieldName = null;
                }
                buffer.setLength(0);
            } else if ("list".equals(qName)) {

     * @param path The FTP path to check.
     * @return true if it matches, false otherwise.
     */
    boolean matches(final String path) {
        if (StringUtil.isBlank(path)) {
            return false;
        }

        try {
            final int pos = path.indexOf('/', 6);
            final URI uri = new URI(pos == -1 ? path : path.substring(0, pos));

        final String endpoint = getInitParameter("endpoint", null, String.class);
        if (StringUtil.isBlank(endpoint)) {
            throw new CrawlingAccessException("endpoint is blank.");
        }
        builder.endpoint(endpoint);
        final String accessKey = getInitParameter("accessKey", null, String.class);
        if (StringUtil.isBlank(accessKey)) {
            throw new CrawlingAccessException("accessKey is blank.");
        }

     * A header is considered valid if its name is not blank and its value is not null.
     * @return true if the header is valid, false otherwise.
     */
    public boolean isValid() {
        if (StringUtil.isBlank(name) || value == null) {
            return false;
        }

        return true;
    }