How to increment json object properties values to dynamically populate the json body of a jmeter request

Question

Using JMeter I need to send a request which contains a body in such a format:

  {
       "key1":"value1",
       "key2":{
          "key21":[
             {
                "key211_1":"valueA",
                "key212_1":"valueToIncrement",
                "key213_1":{
                   "key2131_1":"valueB",
                   "key2132_1":"valueC",
                },
                "key214_1":{
                   "key2141_1":"valueD",
                   "key2142_1":"valueE"
                }
             },
             {
                "key211_2":"valueA",
                "key212_2":"valueToIncrement+1",
                "key213_2":{
                   "key2131_2":"valueB",
                   "key2132_2":"valueC",
                },
                "key214_2":{
                   "key2141_2":"valueD",
                   "key2142_2":"valueE"
                }
             }
          ]
       }
    }

Inside the body I can have a list of many json objects and each object will have some property with an unique id inside the request.

Something like:

{
"key212_1":"1"
},
{
"key212_2":"2"
}
...
{
"key212_2":"n"
}

Because I can have hundreds of objects inside a request body, can I create a logic in Jmeter, so that each time a request is sent, each value from the target property would have a value incremented by 1 in each of these properties without having to manually hardcode values?

Answer 1

You will have to maintain Counter. At the request where you want to increment the value, add a JSR223 Pre Processor. In that you will have to code to increment the value and save it back to the variable and also assign it your Json object.

EDIT :- I tried to simulate your setup as below.

Setup

RESULT