// 先获取用户openid列表
            List<String> openids = wxPhotoUpload.getUserOpenIdList(access_token);
            TreeMap<String, String> params = new TreeMap<>();
            params.put("access_token", access_token);
            // post 提交的参数
            Map<String, Object> mpnewsParams = new HashMap<>();
            mpnewsParams.put("media_id", messageMediaId);
            TreeMap<String,Object> dataParams = new TreeMap<>();
            dataParams.put("touser", openids);
            dataParams.put("mpnews", mpnewsParams);
            dataParams.put("msgtype", "mpnews");
            dataParams.put("send_ignore_reprint", 0);
            String data = JSON.toJSONString(dataParams);
            String URL = "https://api.weixin.qq.com/cgi-bin/message/mass/send?access_token="+access_token; // 正式群发接口
//            String URL = "https://api.weixin.qq.com/cgi-bin/message/mass/preview?access_token="+access_token; // 阅览群发接口
            String jsonStr = HttpClientUtil.post(URL, data);
            if(jsonStr.indexOf("msg_id") != -1 ){
                jsonStr = jsonStr.replaceAll("[\\\\]", "");
                net.sf.json.JSONObject resultJSON= net.sf.json.JSONObject.fromObject(jsonStr);
                if (resultJSON != null && resultJSON.get("msg_id") != null) {
                        groupWxMessage.setUploadTime(new Date());
                        groupWxMessage.setGmtModified(new Date());
                       if(groupWxMessage.getStatus() ==1 ){
                           groupWxMessage.setStatus(2);
                       }
                        i = groupWxMessageMapper.updateByPrimaryKeySelective(groupWxMessage);
                }
            }

Json化数据-调微信接口