How to use JSONSlurper to perform assertion on JSON array response in groovy

Question

I'm trying to write extract the name value "Acura" from a JSON array response by using the location of the value stored in a variable called "jsonFieldName".

Below is the code that I'm trying to do this with, however, everytime i run the script, SOAPUI returns error: "java.lang.NullPointerException: Cannot get property 'name' on null object error at line: 156"

Can someone kindly advise how to do this?

import groovy.json.JsonSlurper
def response = '''{
"makes": [
{
  "id": 200002038,
  "name": "Acura",
  "niceName": "acura",
  "models": [
    {
      "id": "Acura_ILX",
      "name": "ILX",
      "niceName": "ilx",
      "years": [
        {
          "id": 200471908,
          "year": 2014
        }
      ]
    },
    {
      "id": "Acura_ILX_Hybrid",
      "name": "ILX Hybrid",
      "niceName": "ilx-hybrid",
      "years": [
        {
          "id": 200493809,
          "year": 2014
        }
      ]
    },
    {
      "id": "Acura_MDX",
      "name": "MDX",
      "niceName": "mdx",
      "years": [
        {
          "id": 200465929,
          "year": 2014
        }
      ]
    },
    {
      "id": "Acura_RDX",
      "name": "RDX",
      "niceName": "rdx",
      "years": [
        {
          "id": 200467168,
          "year": 2014
        }
      ]
    },
    {
      "id": "Acura_RLX",
      "name": "RLX",
      "niceName": "rlx",
      "years": [
        {
          "id": 100539511,
          "year": 2014
        }
      ]
    },
    {
      "id": "Acura_TL",
      "name": "TL",
      "niceName": "tl",
      "years": [
        {
          "id": 200488448,
          "year": 2014
        }
      ]
    },
    {
      "id": "Acura_TSX",
      "name": "TSX",
      "niceName": "tsx",
      "years": [
        {
          "id": 200490517,
          "year": 2014
        }
      ]
    },
    {
      "id": "Acura_TSX_Sport_Wagon",
      "name": "TSX Sport Wagon",
      "niceName": "tsx-sport-wagon",
      "years": [
        {
          "id": 200673755,
          "year": 2014
        }
      ]
    }
  ]
},
{
  "id": 200001769,
  "name": "Aston Martin",
  "niceName": "aston-martin",
  "models": [
    {
      "id": "Aston_Martin_DB9",
      "name": "DB9",
      "niceName": "db9",
      "years": [
        {
          "id": 200473436,
          "year": 2014
        }
      ]
    },
    {
      "id": "Aston_Martin_Rapide_S",
      "name": "Rapide S",
      "niceName": "rapide-s",
      "years": [
        {
          "id": 200460643,
          "year": 2014
        }
      ]
    },
    {
      "id": "Aston_Martin_V8_Vantage",
      "name": "V8 Vantage",
      "niceName": "v8-vantage",
      "years": [
        {
          "id": 200472947,
          "year": 2014
        }
      ]
    },
    {
      "id": "Aston_Martin_Vanquish",
      "name": "Vanquish",
      "niceName": "vanquish",
      "years": [
        {
          "id": 200431313,
          "year": 2014
        }
      ]
    }
  ]
}
],
"makesCount": 2
}'''

def jsonFieldName = ('makes[0].name')
def json = new JsonSlurper().parseText (response)
jsonFieldName.split("\\.").each{json = json[it]}

assert json == 'Acura'

score 0 · Answer 1 · answered Nov 16 '16 at 05:28

Assuming that your JSON is good from the response (check by calling print) Try adding .text to the end of your jsonSlurper() Call

It also looks like you have a space between parseText and (response) so it should be

def json = new JsonSlurper().parseText(response)

However I would try casting to ArrayList<LazyMap> to ensure you can iterate by
ArrayList<LazyMap> json = new JsonSlurper().parseText(response) as ArrayList<LazyMap>

Then call :
json.get('Acura')

ChrLipp · Answer 2 · 2016-11-16T19:11:12.187

This line of your code doesn't handle the index resolution:

jsonFieldName.split("\\.").each{json = json[it]}

There is no key with the name makes[0]. Instead there is an array of makes and you are interested on the first one. The following hardcoded line retrieves the name attribute:

def result = json.'makes'[0].'name'

As you can see here there is an additional step to resolve the index operator. Of course you can implement this functionality on your own or use JsonPath instead of JsonSlurper.

score 0 · Answer 3 · answered Nov 17 '16 at 00:43

OK so I managed to get this working by using JsonPath instead of JsonSlurper.

To achieve this I had to import the following:

import com.jayway.jsonpath.JsonPath

def jsonFieldName = "makes[0].name"
def expectedValue = "Acura"
def jsonSuff = JsonPath.read(response, jsonFieldName)
log.info(jsonSuff)
if (jsonSuff.toString() == expectedValue.toString()){
    log.info("Actual value"+jsonSuff+"is equal to expected value"+expectedValue)
}

How to use JSONSlurper to perform assertion on JSON array response in groovy

3 Answers3