Apache Nifi - JOLT specification for array of json

Question

I have a JSON flowfile which contains

[
  {
    "Ids": 9,
    "totalOut": 2,
    "outboundOut": 3,
    "timestamp": 98765
  },
  {
    "Ids": 34,
    "totalOut": 7,
    "outboundOut": 9,
    "timestamp": 98760
  },
  {
    "Ids": 54,
    "totalOut": 1,
    "outboundOut": 3,
    "timestamp": 98763
  }
]

I need to sum the totalOut's value, outboundOut's value seperately and i need to sum totalOut's value, outboundOut's value and enrich it as

{
  "totalout_sum": 10,
  "outbound_sum": 15,
  "total_sum": 25
}

Help me to resolve this issue.

Answer 1

You can use the following transformation spec

[
  { // convert attributes suffixed with "Out" to components of
    // the new independent arrays
    "operation": "shift",
    "spec": {
      "*": {
        "total*": "totalout_sum",
        "outbound*": "outbound_sum"
      }
    }
  },
  { // sum of the components of the array to generate desired attributes
    // namely "totalout_sum" and "outbound_sum"
    "operation": "modify-overwrite-beta",
    "spec": {
      "*": "=intSum(@(1,&))"
    }
  },
  { // generate total sum of the values of the newly generated attributes
    "operation": "modify-overwrite-beta",
    "spec": {
      "total_sum": "=intSum(@(1,totalout_sum),@(1,outbound_sum))"
    }
  }
]

the demo on the site is