// 构造 RequestParam
RequestParam requestParam = new RequestParam.Builder()
.serialNumber(wechatPaySerial)
.nonce(wechatpayNonce)
.signature(wechatSignature)
.timestamp(wechatTimestamp)
.body(requestBody)
.build();
其中的 requestBody 是什么
https://pay.weixin.qq.com/wiki/doc/apiv3/apis/chapter3_1_5.shtml
{ "id": "EV-2018022511223320873", "create_time": "2015-05-20T13:29:35+08:00", "resource_type": "encrypt-resource", "event_type": "TRANSACTION.SUCCESS", "summary": "支付成功", "resource": { "original_type": "transaction", "algorithm": "AEAD_AES_256_GCM", "ciphertext": "", "associated_data": "", "nonce": "" } }