code: private SearchFilter getSearchFilter(HttpServletRequest httpServletRequest) {
          SearchFilter ret = new SearchFilter();
          Set<String> keySet = httpServletRequest.getParameterMap().keySet();
          for (String key : keySet) {
              ret.setParam(String.valueOf(key), String.valueOf(httpServletRequest.getParameter(key)));
          }
  
          return ret;
      }
docs: Populate a SearchFilter on the basis of the Query Parameters
  @return