code: public void addParameters(String url)
     {
        if ((url != null) && !"".equals(url))
        {
           url = url.trim();
           if (url.length() > 1)
           {
              if (url.contains("?"))
              {
                 url = url.substring(url.indexOf('?') + 1);
              }
  
              String pairs[] = url.split("&(amp;)?");
              for (String pair : pairs)
              {
                 String name;
                 String value;
                 int pos = pair.indexOf('=');
                 // for "n=", the value is "", for "n", the value is null
                 if (pos == -1)
                 {
                    name = pair;
                    value = null;
                 }
                 else
                 {
                    try
                    {
                       // FIXME This probably shouldn't be happening here.
                       name = URLDecoder.decode(pair.substring(0, pos), "UTF-8");
                       value = URLDecoder.decode(pair.substring(pos + 1, pair.length()), "UTF-8");
                    }
                    catch (IllegalArgumentException e)
                    {
                       // thrown by URLDecoder if character decoding fails
                       log.warn("Ignoring invalid query parameter: " + pair);
                       continue;
                    }
                    catch (UnsupportedEncodingException e)
                    {
                       throw new PrettyException(
                                "UTF-8 encoding not supported. Something is seriously wrong with your environment.");
                    }
                 }
                 List<String> list = parameters.get(name);
                 if (list == null)
                 {
                    list = new ArrayList<String>();
                    parameters.put(name, list);
                 }
                 list.add(value);
              }
           }
        }
        return;
     }
docs: Add parameters from the given URL. If a '?' character is encountered in the URL, the any characters up to and
  including the first '?' will be ignored. If a parameter already exists, append new values to the existing list of
  values for that parameter.