docs: public String getRequstURIPath(String prefix, String defvalue) {
          if (requestURI == null || prefix == null || prefix.isEmpty()) return defvalue;
          int pos = requestURI.indexOf(prefix);
          if (pos < 0) return defvalue;
          String sub = requestURI.substring(pos + prefix.length());
          pos = sub.indexOf('/');
          return pos < 0 ? sub : sub.substring(0, pos);
      }