Correlating JSON Response Body in JMeter

Question

I tried to design a test script of API Load Testing in JMeter 5.0. Here is my thread group info:

Below is the Body Data, I already added some variables and functions to it. You can also view the sample JSON Body Data at here:

    {
    "app_name": "Telekom",
    "source": "MOENGAGE",
    "moe_request_id": "req_${__threadNum}",
    "events": [
        {
            "event_name": "Email Opened",
            "event_code": "MOE_EMAIL_OPEN",
            "event_uuid": "${__UUID}",
            "event_time": ${__jexl3(${__time(,)}/1000,)},
            "event_type": "CAMPAIGN_EVENT",
            "event_source": "MOENGAGE",
            "uid": "${__counter(,)}-${__RandomString(7,ABCDEFG123456)}${uid}",
            "email_id": "${email}",
            "event_attributes": {
                "campaign_id": "${__RandomString(24,abcdefghijklmn123456789)}",
                "campaign_name": "July2021_16072021_LigaSuper_English",
                "campaign_type": "GENERAL",
                "campaign_channel": "EMAIL",
                "moe_delivery_type": "One Time",
                "moe_campaign_tags": [
                    "engagement"
                ],
                "moe_campaign_channel": "Email",
                "u_em": "${email}"
            },
            "user_attributes": {
                "PRODUCT_TYPE": "Unifi",
                "moengage_user_id": "60dc48d4d722040a2e78b788",
                "SERVICE_NO": "${uid}",
                "id": "${email}"
            },
            "device_attributes": {}
        }
    ]
}

I also include JSON Extractor to do correlation on the response body:

Here is the results in View Results Tree. Added Debug Sampler to see the whether my parameterization and correlation working or not. Fortunately, only my parameterization is working, while correlation is not.

Updated: This is example of response body:

I want to correlate at "rqUuid": "urn:uuid:1a5d8617-258c-49f7-b1a7-5b8ee71fb9fd" in the response body. Question is, is this the correct way to correlate the JSON Body? Do I need to correlate the response body although I already define the function "event_uuid": "${__UUID}" in the Body Data?

Thanks. Appreciate your help.

Masud Jahan Masud Jahan · Accepted Answer · 2021-08-09T05:44:16

You are using a regular expression to get your data from a JSON response using the JSON Extractor. You need to use JSON Path Expressions instead of using regular expressions.

If you want to extract event_uuid from the response, your json path expressions would be events[*].event_uuid

To get the first event_uuid of your events array objects, you can use events[0].event_uuid

Correlating JSON Response Body in JMeter

3 Answers