* strip invalid XML characters, and parse XML content into a map of data.
 *
 * <p>
 * The class is final and cannot be instantiated.
 * </p>
 *
 * <h2>Methods:</h2>
 * <ul>
 *   <li>{@link #escapeXml(String)}: Escapes special characters in an XML string.</li>
 *   <li>{@link #stripInvalidXMLCharacters(String)}: Strips invalid XML characters from a string.</li>

        if (m.matches() && m.groupCount() > 0) {
            return m.group(1);
        }
        return null;
    }

    /**
     * Strips comments from a line (everything after '#' character).
     * @param line the line to strip comments from
     * @return the line without comments
     */
    protected String stripComment(final String line) {
        final int commentIndex = line.indexOf('#');

            final String[] strings = name.split("\\.");
            final StringBuilder buf = new StringBuilder(100);
            if (strings.length > 1) {
                for (int i = 0; i < strings.length - 1; i++) {
                    if (buf.length() != 0) {
                        buf.append('.');
                    }
                    buf.append(strings[i]);
                }

            final String[] strings = name.split("\\.");
            final StringBuilder buf = new StringBuilder(100);
            if (strings.length > 1) {
                for (int i = 0; i < strings.length - 1; i++) {
                    if (buf.length() != 0) {
                        buf.append('.');
                    }
                    buf.append(strings[i]);
                }

        } finally {
            xpathAPI.remove();
        }
    }

    /**
     * Extracts strings from a document using the specified XPath expression.
     *
     * @param document the DOM document to extract strings from
     * @param path the XPath expression to evaluate
     * @return an array of strings extracted from the document
     */

/**
 * Helper class for converting URLs based on a set of predefined rules.
 *
 * <p>This class provides functionality to convert URLs by replacing parts of the URL
 * based on a map of target strings and their corresponding replacements. It allows
 * adding new conversion rules, setting the entire conversion map, and converting
 * URLs using these rules.</p>
 *

            final PDFTextStripper stripper = new PDFTextStripper();
            final AtomicBoolean done = new AtomicBoolean(false);
            final PDDocument doc = document;
            final Set<Exception> exceptionSet = new HashSet<>();
            final Thread task = new Thread(() -> {
                try {
                    stripper.writeText(doc, writer);

 *   <li>Dynamic passwords provided through extraction parameters</li>
 * </ul>
 *
 * <p>Passwords are matched against URLs or resource names using regular expression patterns.
 * The extractor first tries to match against the URL, then falls back to the resource name if available.
 *
 * @author shinsuke
 */
public abstract class PasswordBasedExtractor extends AbstractExtractor {

    /** Logger instance for this class. */

    }

    /**
     * Retrieves an extractor for the specified key.
     * If multiple extractors are associated with the key, returns a composite extractor
     * that tries each extractor in order until one succeeds.
     *
     * @param key the key to look up
     * @return the extractor for the key, or null if not found
     */
    public Extractor getExtractor(final String key) {

 *     <li>Retrieve the stored file as a File object.</li>
 * </ul>
 *
 * <p>
 * The class uses several configurable properties to customize the file storage behavior,
 * such as the base path, replacement strings for special characters in URLs,
 * the maximum number of duplicated paths to attempt, and the character set for encoding the file path.
 * </p>
 *
 * <p>