CODEWITHSUNDEEP
jmeterjsonpath
Aliaksei Bulhak
Aliaksei Bulhak

Reputation: 6208

Obtain index of random element from json array in JMeter Json Path Post Processor

I have strange case for jmeter. Imagine that we have an json array with elements like this:

{
  "id"  : 123456,
  "name": "TEST"
}

So I want to get random element from array that has id. For this case I use Json Path PostProcessor with expression like this $.elements[?(@.id)]

But for some reasons I need an index of this element. So I can create BeanShellPostProcessor generate random index and then use same Json Path PostProcessor with expression like this $.elements[${PARAM_ElementIndex}]. But in some cases this array can be empty and Json Path PostProcessor wil fail with exception like this: jmeter.extractor.json.jsonpath.JSONPostProcessor: Error processing JSON content in PARAM_ResumeId, message:No results for path: $['elements'][0]['id']

So may be someone can suggest any solution

Upvotes: 1

Views: 2672

Answers (1)

Dmitri T
Dmitri T

Reputation: 168132

I would recommend use Groovy instead of Beanshell as:

  • Well-behaved Groovy scripts can be compiled into bytecode therefore performance will be much higher
  • Groovy has built-in JSON support

So given you have JSON Response like:

{
  "elements": [
    {
      "id": 123456,
      "name": "TEST"
    },
    {
      "id": 7890,
      "name": "TEST2"
    }
  ]
}

You can extract random ID along with its index using the following example Groovy code in the JSR223 PostProcessor:

import groovy.json.JsonSlurper

import java.util.concurrent.ThreadLocalRandom

String response = prev.getResponseDataAsString()

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

int size = json.elements.size

if (size > 0){
    def randomIndex = ThreadLocalRandom.current().nextInt(size)
    def value = json.elements.get(randomIndex).id
    log.info('Index: ' + randomIndex)
    log.info('Value: ' + value)
}

Demo:

Groovy JSON JMeter

References:

Upvotes: 2

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