@Override
	public JSONObject main(Map<String, String> params, Session session)
			throws Exception {
		JSONObject rtn = new JSONObject();
		
		long uid = session.getActiveUserId();
		// if no active user
		if(uid==0) {
			rtn.put("rtnCode", this.getRtnCode(201));
			return rtn;
		}
		User activeUser = User.findById(uid);
		rtn.put("rtnCode", this.getRtnCode(200));
		{
			JSONObject userJo = new JSONObject();
			userJo.put("username", activeUser.username);
			userJo.put("id", activeUser.getId());
			rtn.put("user", userJo);
		}
		return rtn;
	}