Nifi : Is it possible to create multiple flow file based on attributes ?

[#1]

Hello,

I receive a json from a HTTP Request. It looks like this : 

{
  "accessToken" : "token",
  "expiresIn" : "12600",
  "refreshToken" : "token",
  "tokenType" : "Bearer",
  "usagePointsId" : "22516914714270, 22516914714270, 22516914714270"
}

I have the usagePointsId key containing a string with multiple values. 
I will need each values to include them in different API calls.
I would therefore like to be able to separate the string at the comma level to extract each value.
Then the idea is to create a new unique flow file for each value. This value would be associated with a "usagePointId" attribute which would be used in my API calls. Also, the others json key would be added as Attributes for each flow files

I don't know if it's possible to create multiple differents flow file based on a split attributes. 
I tried to use the ExecuteScript (with ECMASCRIPT) to split the string and create Flow Files with something like this :

flowFile = session.get()

if (!flowFile) return
usagePointsId = flowFile.getAttribute('usagePointsId')
splitStr = usagePointsId.split(",");
let attrs = []

for (let i = 0; i < spltStr.length, i+) {
	newFlowFile = session.create()
	newFlowFile = session.write(newFlowFile, splitStr[i] )
	session.transfer(newFlowFile, REL_SUCCESS)
}

Someone could help me with that kind of issue ?

Thanks

[#2]

I tried to transform the usagePointsId String to an array of element using a jolt transformation :

    {
    "operation": "modify-overwrite-beta",
    "spec": {
        "usagePointsId": "=split(',',@(1,usagePointsId))"
    }
  }

output : 

"usagePointsId" : [ "22516914714270", " 22516914714271", " 22516914714272" ]

Then i split this array with SplitJson on the usagePointsId path.

It results multiple files with a simple string in content : 

How can i save that kind of data as Attributes ? I try to use EvaluateJsonPath but unfortunatly, there is no path to precise. Is there a way to handle that ? 

[#3 · Accepted solution]

I finally used a Jolt transformation on the last ouput content :
input :

22516914714270

jolt spec :

[
  {
     "operation": "shift",
    	"spec": {
          "*": {
                  "$": "usagePointsId"
          }
    }
  }
]

ouput :
{"usagePointsId": "22516914714270"}

Then i used the EvaluateJsonPath to save the value as attributes

What a day 😅