钉钉ivs 创建套件回调，Random为空

String token = "xxxxqaz2WSX";
            String aseKey = "xxxxxxxxx";
            DingTalkEncryptor dingTalkEncryptor = new DingTalkEncryptor(token, aseKey, "xxxxxxxx");
            String encryptMsg = json.getString("encrypt");
            String plainText = dingTalkEncryptor.getDecryptMsg(signature, timestamp, nonce, encryptMsg);
            JSONObject callbackMsgJson = JSONObject.parseObject(plainText);
             String random = callbackMsgJson.getString("Random");
            String responseEncryMsg = random;
            Map<String, String> encryptedMap = dingTalkEncryptor.getEncryptedMap(responseEncryMsg, System.currentTimeMillis(), com.dingtalk.oapi.lib.aes.Utils.getRandomStr(8));
            return encryptedMap;


  红色字体一行，值为空，报错/**加密明文文本非法**/ ，不知道怎么回事，求助，谢谢~~~~~！！！！！！！！！！！！！！！