微信新版沙箱密钥 获取方式

public  String GetSignKey() throws Exception {
   String nonce_str = WXPayUtil.generateNonceStr();//生成随机字符
   Map<String, String> param = new HashMap<String, String>();
   param.put("mch_id", payConfig.getMchId());//需要真实商户号
   param.put("nonce_str", nonce_str);//随机字符
   String sign = WXPayUtil.generateSignature(param,payConfig.getMchKey(),WXPayConstants.SignType.MD5);//通过SDK生成签名其中API_KEY为商户对应的真实密钥
   param.put("sign", sign);
   String xml = WXPayUtil.mapToXml(param);//将map转换为xml格式
   String url = "https://api.mch.weixin.qq.com/xdc/apiv2getsignkey/sign/getsignkey";//沙箱密钥获取api
   String SignKey = HttpUtil.postData(url, xml);//
   System.out.println("signkey+"+SignKey);
   Map<String, String> param1 = new HashMap<String, String>();
   param1 = WXPayUtil.xmlToMap(SignKey);
   String key = param1.get("sandbox_signkey");
   return key;
}

我直接用postman   打 https://api.mch.weixin.qq.com/xdc/apiv2getsignkey/sign/getsignkey

记得请求头改成那啥