关于jsf和list

List usernames = new ArrayList();后面是查询数据库获得ResultSet rs；
while(rs.next()){
  String userName = rs.getString("user_name");
  String cityName = rs.getString("city_name");
  rs.getInt("user_id");
  rs.getInt("city_id");
  userNames.add(new UserBean(userName,cityName,userId,cityId));
  }然后我在页面中用#{usernames.userId}，为什么显示一系列乱码，userName和cityName能正常显示的。