In Jmeter, What would be syntax of parameters in Body Data section of HTTP Request Sampler, for Rest APIs and input should be generated dynamically

Question

I'm trying to generate my input through JavaScript using BSF PreProcessor. Currently I've only BSF PrepProcessor and a HTTP Request. My Request body goes like this.,

{
    "entity": {
        "id": "${EnitityName}",
        ----
     }
}

The randomly generated string should be the value for ID, i've parameterized how we normaly do it. This is not working. Can somebody tell me where i'm going wrong or any alternative approach.

FYI, JMeter is not inserting the result of my script into the variable ${EntityName} — Ashwin

Naveen Kumar R B Naveen Kumar R B · Accepted Answer · 2017-03-02T07:36:52

try using __RandomString function: (no need of JavaScript & BSF PreProcessor if you want a random string)

{
    "entity": {
        "id": "${__RandomString(8,abcdefghiz,)}",
        ----
     }
}

From Docs:

Examples:

${__RandomString(5)} will return a random string of 5 characters which can be readable or not

${__RandomString(10,abcdefg)} will return a random string of 10 characters picked from abcdefg set, like cdbgdbeebd or adbfeggfad, …

${__RandomString(6,a12zeczclk, MYVAR)} will return a random string of 6 characters picked from a12zeczclk set and store the result in MYVAR, MYVAR will contain string like 2z22ak or z11kce, …

In Jmeter, What would be syntax of parameters in Body Data section of HTTP Request Sampler, for Rest APIs and input should be generated dynamically

2 Answers