获取直播间列表接口

https://api.weixin.qq.com/wxa/business/getliveinfo?access_token=

为什么有时候获取不到直播间列表

List liveStatusDTOS = null;
    try {
        //获取access_token
        JSONObject accessToken = getAccessToken();
        String access_token = (String) accessToken.get("access_token");
        String httpurl = "https://api.weixin.qq.com/wxa/business/getliveinfo?access_token=" + access_token;
        liveStatusDTOS = null;
        //参数封装
        Map mapParam = new HashMap<>();
        mapParam.put("start", 0);
        mapParam.put("limit", 500);
        JSONObject jsonData = restTemplate.postForObject(httpurl, mapParam, JSONObject.class);
        if (null != jsonData) {
            ArrayList statusDTOS = (ArrayList) jsonData.get("room_info");
            if (CollectionUtils.isNotEmpty(statusDTOS)) {
                String jsonString = JSONObject.toJSONString(statusDTOS);
                liveStatusDTOS = JSONArray.parseArray(jsonString, LiveStatusDTO.class);
            }

        }
    } catch (RestClientException e) {
        logger.info(String.format("获取微信小程序直播列表异常,e = %s", e));
    }
    return liveStatusDTOS;
}