public List<Map<String, String>> getUserInfo() {
   Collection<ClientSession> sessions = SessionManager.getInstance().getSessions();
   List<Map<String, String>> list = new ArrayList<Map<String, String>>();
   Map<String, String> u = null;
   for (ClientSession s : sessions) {
     if (s.getAuthToken() == null) continue;
     u = new HashMap<String, String>();
     try {
       @SuppressWarnings("unchecked")
       List<UserGroup> groups = ((List<UserGroup>) s.getSessionData("groups"));
       if (groups != null && groups.size() > 0) {
         String gname = "";
         for (UserGroup ug : groups) {
           gname += ug.getSGroupName() + ",";
         }
         if (gname.length() > 0) {
           gname = gname.substring(0, gname.length() - 1);
         }
         u.put("ugroup", gname);
       } else {
         u.put("ugroup", "");
       }
       u.put("username", s.getUsername());
       u.put("ip", s.getHostName());
       u.put("id", s.getStreamID());
       list.add(u);
     } catch (UserNotFoundException e) {
       // TODO Auto-generated catch block
       e.printStackTrace();
     } catch (UnknownHostException e) {
       // TODO Auto-generated catch block
       e.printStackTrace();
     }
   }
   return list;
 }