code: private static String quoteReplacement(final String s) {
      if (s.indexOf('\\') == -1 && s.indexOf('$') == -1) {
        return s;
      }
      final StringBuffer sb = new StringBuffer();
      for (int i = 0; i < s.length(); i++) {
        final char c = s.charAt(i);
        if (c == '\\') {
          sb.append('\\');
          sb.append('\\');
        } else if (c == '$') {
          sb.append('\\');
          sb.append('$');
        } else {
          sb.append(c);
        }
      }
      return sb.toString();
    }
docs: /* for jdk 1.4