static String unescape(final String str) throws NumberFormatException, UnsupportedEncodingException {
        char ch;
        int i, j, state, len;
        char[] out;
        final byte[] b = new byte[1];

        if (str == null) {
            return null;
        }

        len = str.length();
        out = new char[len];
        state = 0;
        for (i = j = 0; i < len; i++) {
            switch (state) {

    if (!PART_CHAR_MATCHER.matchesAllOf(asciiChars)) {
      return false;
    }

    // No initial or final dashes or underscores.

    if (DASH_MATCHER.matches(part.charAt(0))
        || DASH_MATCHER.matches(part.charAt(part.length() - 1))) {
      return false;
    }

    /*
     * Note that we allow (in contravention of a strict interpretation of the relevant RFCs) domain

        return getByName(hostname, false);
    }

    static boolean isDotQuadIP(final String hostname) {
        if (hostname != null && hostname.length() > 0 && Character.isDigit(hostname.charAt(0))) {
            int i, len, dots;
            char[] data;

            i = dots = 0; /* quick IP address validation */
            len = hostname.length();
            data = hostname.toCharArray();

    byte[] bytes = new byte[string.length() / 2];
    for (int i = 0; i < string.length(); i += 2) {
      int ch1 = decode(string.charAt(i)) << 4;
      int ch2 = decode(string.charAt(i + 1));
      bytes[i / 2] = (byte) (ch1 + ch2);
    }
    return fromBytesNoCopy(bytes);
  }

  private static int decode(char ch) {
    if (ch >= '0' && ch <= '9') {
      return ch - '0';
    }
    if (ch >= 'a' && ch <= 'f') {

     * @param hostname the hostname to check
     * @return whether this is an IP address
     */
    public static boolean isDotQuadIP(final String hostname) {
        if (Character.isDigit(hostname.charAt(0))) {
            int i, len, dots;
            char[] data;

            i = dots = 0; /* quick IP address validation */
            len = hostname.length();
            data = hostname.toCharArray();

            int i = 0;
            do {
                if (i >= buf.length) {
                    final char[] nb = new char[buf.length * 2];
                    System.arraycopy(buf, 0, nb, 0, buf.length);
                    buf = nb;
                }
                buf[i++] = (char) peekc;
                peekc = read();
                peekct = peekc < 0 ? CT_WHITESPACE : peekc < 256 ? ctype[peekc] : CT_ALPHA;

        final StringBuilder sb = new StringBuilder();
        String n = name;

        // fix MSBROWSE name
        if (n == null) {
            n = "null";
        } else if (n.charAt(0) == 0x01) {
            final char c[] = n.toCharArray();
            c[0] = '.';
            c[1] = '.';
            c[14] = '.';
            n = new String(c);
        }

    return normalizeWord(word);
  }

  private static String firstCharOnlyToUpper(String word) {
    return word.isEmpty()
        ? word
        : Ascii.toUpperCase(word.charAt(0)) + Ascii.toLowerCase(word.substring(1));
  }

    // read char by char
    CharSequenceReader reader = new CharSequenceReader(charSequence);
    for (int i = 0; i < expected.length(); i++) {
      assertEquals(expected.charAt(i), reader.read());
    }
    assertFullyRead(reader);

    // read all to one array
    reader = new CharSequenceReader(charSequence);
    char[] buf = new char[expected.length()];

            return filename;
        }
        final StringBuilder buf = new StringBuilder(filename.length() + 10);
        for (int i = 0; i < filename.length(); i++) {
            final char c = filename.charAt(i);
            switch (c) {
            case '?':
                buf.append("%3f");
                break;
            case '#':
                buf.append("%23");
                break;