签名校验正确[图片]但是一直拿不到预支付id

String grant_type = "client_credential"; String url = "https://api.weixin.qq.com/cgi-bin/token"; String param = "grant_type="+grant_type+"&appid="+appid+"&secret="+appSecret; String access_token = HttpRequest.sendGet(url, param); Map<String,Object> map = JSON.parseObject(access_token); System.out.println("---"+map.get("access_token")); String begin_date = new SimpleDateFormat("yyyyMMdd").format(new Date()); System.out.println("date===:"+begin_date); Calendar ca = Calendar.getInstance();//得到一个Calendar的实例  ca.setTime(new Date()); //设置时间为当前时间 ca.add(Calendar.DATE, -1); Date lastMonth = ca.getTime(); String end_date = new SimpleDateFormat("yyyyMMdd").format(lastMonth); System.out.println("end_date===:"+end_date); String url1 = "https://api.weixin.qq.com/datacube/getweanalysisappiddailyvisittrend?access_token="+map.get("access_token"); String param1 = "&end_date=20170313&begin_date=20170313"; String JsonList = HttpRequest.sendPost(url1, param1); System.out.println(JsonList); 报：{"errcode":61500,"errmsg":"date format error hint: [x9JRTA02761556]"}