How I can get a random value string in href by JSON Path Extractor with JMeter? - jmeter

Question

I have JSON responce
{
"sessionName":"eL7tYgxhYh",
"imageSrc":"/Common/CaptchaImage/**eL7tYgxhYh**?t=636573960197174426"
}
How I can get a random value string "eL7tYgxhYh" in href by JSON Path Extractor with JMeter?

Answer 1

You cannot achieve this using JSON Extractor as it can only deal with JSON Objects, i.e. you can easily get full value of the imageSrc attribute, but not more.
I would recommend switching to Boundary Extractor instead, the relevant configuration would be something like:
Name of created variable: anything meaningful, i.e. href
Left Boundary: CaptchaImage/
Right Boundary: ?
That's it, the "interesting" value should be now extracted and you should be able to refer it as ${href} where required
Demo:
More information: The Boundary Extractor vs. the Regular Expression Extractor in JMeter

Answer 2

JSON format is in key-value pair so you just need to mention the key for which you need to extract the value. As in your case, you can use following JSON path expression for fetching the text mentioned by you:
$.sessionName
You can also use regular expression extractor which is another most important element of JMeter to extract the dynamic variables. Please refer to below blog of RedLine13 for more information on Regular Expressions:
https://www.redline13.com/blog/2016/01/jmeter-extract-and-re-use-as-variable/
Let me know if you have any further question

Answer 3

Above figure shows how to access access_token response of json and store it in access_token variable. In your case need to replace below.
JSONPath Expression use
$..sessionName
Destination variable Name
SessionName
more information for accessing json path
To Get "636573960197174426"
To get required string from result string you can use BeanShell Assertion to split the string.
And Use link to fetch the vaiable properties and jmeter elements
To Fetch jmeter Elements