code: protected Collection<String> getReqPars(final HttpServletRequest req,
                                            final String name) throws Throwable {
      String[] s = req.getParameterValues(name);
      ArrayList<String> res = null;
  
      if ((s == null) || (s.length == 0)) {
        return null;
      }
  
      for (String par: s) {
        par = Util.checkNull(par);
        if (par != null) {
          if (res == null) {
            res = new ArrayList<String>();
          }
  
          res.add(par);
        }
      }
  
      return res;
    }
docs: Get a multi-valued request parameter stripped of white space.
  Return null for zero length.
  
  @param req
  @param name    name of parameter
  @return  Collection<String> or null
  @throws Throwable