直接打印 $buffer->rawBody() 看下吧
{
"Name": "heartbeatRequest",
"TimeStamp": 1594713882,
"Data": {
"DeviceInfo": {
"DeviceId": "10149445",
"DeviceUUID": "umettqtdmsdy",
"DeviceMac": "00:11:04:02:28:a4",
"DeviceIp": "192_168_101_88",
"WebVersion": "7_18_1_KD3_1_14_8_5",
"CoreVersion": "17_17_1_40",
"VersionDate": "Jun_19_2020_09:40:43",
"ChannelNo": 0
},
"HTTPVersion": "V2_0_1",
"HTTPDate": "2020-04-02",
"HeartbeatCount": 0,
"CaptureCount": 0
}