key multiPart missing

[marcoratto]

I have a problem using the key "MultiPart" for the key "Metadata".
I wrote a java sample code:
IssueMetaDataMultiPart.java.txt

This is the output written on the console:
`
MetaData [isMultiPart=true, contentType=text/plain, size=12, seq=0, fileName=fileName, fileType=fileType, md5=md5, description=config]

Metric [name=file, alias=1234, timestamp=1718715733989, dataType=String, isHistorical=null, isTransient=null, metaData=MetaData [isMultiPart=true, contentType=text/plain, size=12, seq=0, fileName=fileName, fileType=fileType, md5=md5, description=config], properties=null, value=Hello world!, isNull=false]
`

This is the message send to the Broker MQTT:

{
"timestamp": 1718715733989,
"metrics": [
{
"name": "file",
"alias": 1234,
"timestamp": 1718715733989,
"dataType": "String",
"metaData": {
"contentType": "text/plain",
"size": 12,
"seq": 0,
"fileName": "fileName",
"fileType": "fileType",
"md5": "md5",
"description": "config"
},
"value": "Hello world!"
}
],
"seq": 0
}

the key isMultiPart is missing.
I tried the same code with the Tahu Libraries 1.0.0 and 1.0.7 but it doesn't work.

Someone could help me ?

thanks in advance
Marco

[wes-johnson]

What tool are you using to view the resulting message?

[marcoratto]

I'm using mqttfx but I also wrote a Java class for encode and decode sparkplug messages and I have always the same issue.

[wes-johnson]

I know the last version of MQTT.fx I used didn't properly display all portions of the Metric including the MetaData. Based on your code, I think you've set it up properly. What does your decoder code look like? What if you use the Tahu decoder?

[marcoratto]

I tried with a python script:

./DecodeSparkplugB.py` ../../../cmdFileUpload.bin

timestamp: 1718803102
metrics {
name: "cmdFileUpload"
alias: 10000
timestamp: 1718803102
datatype: 12
is_null: false
metadata {
content_type: "application/json"
size: 46
seq: 0
file_name: "12"
file_type: "base64"
md5: "bd694094acf029e4db780a322fcd7611"
description: "config"
}
string_value: "ewogICJJRUMtMTA0LVNsYXZlIjogewogICAgInZlcnNpb24iOiAxCiAgfQp9Cg=="
}
seq: 18446744073709551615

and with a java tahu example.

{

"timestamp": 1718887068,
"metrics": [
{
"name": "cmdFileUpload",
"alias": 10000,
"timestamp": 1718887068,
"dataType": "String",
"metaData": {
"contentType": "application/json",
"multiPart": true,
"size": 46,
"seq": 0,
"fileName": "12",
"fileType": "base64",
"md5": "bd694094acf029e4db780a322fcd7611",
"description": "config"
},
"value": "ewogICJJRUMtMTA0LVNsYXZlIjogewogICAgInZlcnNpb24iOiAxCiAgfQp9Cg=="
}
]
}

Metric [name=cmdFileUpload, alias=10000, timestamp=Tue Jan 20 22:28:07 CET 1970, dataType=String, isHistorical=null, isTransient=null, isNull=false, metaData=MetaData [isMultiPart=true, contentType=application/json, size=46, seq=0, fileName=12, fileType=base64, md5=bd694094acf029e4db780a322fcd7611, description=config], propertySet=null, value=ewogICJJRUMtMTA0LVNsYXZlIjogewogICAgInZlcnNpb24iOiAxCiAgfQp9Cg==]

java -jar ./java/examples/listener/target/example_listener-1.0.7.jar
Message Arrived on Sparkplug topic SparkplugListener/Sparkplug B Devices/NCMD/Python Edge Node 1
Message Arrived on Sparkplug topic SparkplugListener/Sparkplug B Devices/NCMD/Python Edge Node 1
14:37:48.733 [MQTT Call: SparkplugBListenerEdgeNode] TRACE o.e.t.m.SparkplugBPayloadDecoder - For metricName=cmdFileUpload and alias=10000 - handling metric type in decoder: 12
{
"timestamp" : 1718887068,
"metrics" : [ {
"name" : "cmdFileUpload",
"alias" : 10000,
"timestamp" : 1718887068,
"dataType" : "String",
"metaData" : {
"contentType" : "application/json",
"size" : 46,
"seq" : 0,
"fileName" : "12",
"fileType" : "base64",
"md5" : "bd694094acf029e4db780a322fcd7611",
"description" : "config",
"multiPart" : false
},
"value" : "ewogICJJRUMtMTA0LVNsYXZlIjogewogICAgInZlcnNpb24iOiAxCiAgfQp9Cg=="
} ],
"seq" : -1
}

Json sample:
{
"timestamp": 1718803102,
"metrics": [
{
"name": "cmdFileUpload",
"alias": 10000,
"timestamp": 1718803102,
"dataType": "String",
"metaData": {
"contentType": "application/json",
"multiPart": true,
"size": 46,
"seq": 0,
"fileName": "12",
"fileType": "base64",
"md5": "bd694094acf029e4db780a322fcd7611",
"description": "config"
},
"value": "ewogICJJRUMtMTA0LVNsYXZlIjogewogICAgInZlcnNpb24iOiAxCiAgfQp9Cg=="
}
]
}

hex dump for the binary message:

hexdump -C cmdFileUpload.bin

00000000 08 9e b5 cb b3 06 12 ac 01 0a 0d 63 6d 64 46 69 |...........cmdFi|
00000010 6c 65 55 70 6c 6f 61 64 10 90 4e 18 9e b5 cb b3 |leUpload..N.....|
00000020 06 20 0c 38 00 42 4c 12 10 61 70 70 6c 69 63 61 |. .8.BL..applica|
00000030 74 69 6f 6e 2f 6a 73 6f 6e 18 2e 20 00 2a 02 31 |tion/json.. .*.1|
00000040 32 32 06 62 61 73 65 36 34 3a 20 62 64 36 39 34 |22.base64: bd694|
00000050 30 39 34 61 63 66 30 32 39 65 34 64 62 37 38 30 |094acf029e4db780|
00000060 61 33 32 32 66 63 64 37 36 31 31 42 06 63 6f 6e |a322fcd7611B.con|
00000070 66 69 67 7a 40 65 77 6f 67 49 43 4a 4a 52 55 4d |figz@ewogICJJRUM|
00000080 74 4d 54 41 30 4c 56 4e 73 59 58 5a 6c 49 6a 6f |tMTA0LVNsYXZlIjo|
00000090 67 65 77 6f 67 49 43 41 67 49 6e 5a 6c 63 6e 4e |gewogICAgInZlcnN|
000000a0 70 62 32 34 69 4f 69 41 78 43 69 41 67 66 51 70 |pb24iOiAxCiAgfQp|
000000b0 39 43 67 3d 3d 18 ff ff ff ff ff ff ff ff ff 01 |9Cg==...........|
000000c0
`

I tried also on this website :
https://protobuf-decoder.netlify.app/

to decode the Protobuf message and I don't find the definition of the key "multiPart":

[marcoratto]

I solved the problem using the latest version of the library 1.0.7.