Working with json using EvaluateJsonPath in Apache Nifi

A) Fetch json array from json object using EvaluateJsonPath in Apache Nifi

For a given json find phoneNumbers json array

{

  "firstName": "John",

  "lastName" : "doe",

  "age"      : 26,

  "address"  : {

    "streetAddress": "naist street",

    "city"         : "Nara",

    "postalCode"   : "630-0192"

  },

  "phoneNumbers": [

    {

      "type"  : "iPhone",

      "number": "0123-4567-8888"

    },

    {

      "type"  : "home",

      "number": "0123-4567-8910"

    }

  ]

}

Then use below

$.phoneNumbers[:]

Result

[

  {

    "type": "iPhone",

    "number": "0123-4567-8888"

  },

  {

    "type": "home",

    "number": "0123-4567-8910"

  }

]

B) For given json find first object from array and get its “type” from the object

[

  {

    "type": "iPhone",

    "number": "0123-4567-8888"

  },

  {

    "type": "home",

    "number": "0123-4567-8910"

  }

]

Fetch first json and the type of it

$[0].type

Online json query tool is a great help

http://www.jsonquerytool.com/