Get the first key from JSON response using JMeter JSON extractor

Question

I am getting below response while running an API.

{
    "bookingId": 0,
    "bookingIds": {
        "13320134": "2023-05-01T04:30:00",
        "13320135": "2023-05-02T04:30:00",
        "13320136": "2023-05-03T04:30:00"
    },
    "conflictDates": null,
    "recurrenceID": 1710459
}

I want to get the first value inside 'bookingIds'

13320134

What I tried:

$.bookingIds.13320134

Output

[
  "2023-05-01T04:30:00"
]

Is it possible using JSON extractor or do I need to achieve this using javascript?

Answer 1

Based upon your comment (as mentioned the second one is getting selected), you can use a JSR223 Post processer and add the following code,

import groovy.json.JsonSlurper;
import java.util.regex.Pattern;


def response = new groovy.json.JsonSlurper().parse(prev.getResponseData());
def bkId = [];

response.bookingIds.each { bookingIdsFetched-> 
    bkId << bookingIdsFetched
}
def value = bkId[0].toString();
def pattern = Pattern.compile('(.+?)=');
def (_, refValue) = (value =~ pattern)[0]

log.info("Reference Value : "+refValue)

Answer 2

I don't think you can get keys using JSON Extractor.

It's possible with:

1. JSON JMESPath Extractor:

   query: bookingIds | keys (@) [0]

   

   

2. JSR223 PostProcessor with Groovy language:

   new groovy.json.JsonSlurper().parse(prev.getResponseData()).bookingIds.keySet()[0]
   

   

Answer 3

I guess the Json Extractor is desined to extract the values and not keys.

You can have multiple extractors to do the job for you

1. Use the json extractor to get the entire bookingIds Object
2. Use a Regex extractor to filter the first key from the extracted json output