How to define a variable as part of an extractor post-processor?

You can follow this tutorial to define a variable as part of an extractor post-processor.

1. Open Get-Exchange-Rate.jmx.

2. Add a post-processor, Regular Expression Extractor, after the "Latest Exchange Rate" HTTP request:

Reference Name: base
Regular Expression: "base": *"(...)"
Template: $1$
Match No.: 1
Default Value: USD

The above settings define a new variable called "base" with the value from a regular expression match process. "Template: $1$" says to take the value from the first matched group. "Match No.: 1" says to take the value from the first match expression pattern.

3. Save the test plan as Get-Exchange-Rate-2.jmx, and run it.

Assume that we get the following output from the HTTP request

{
    "base": "EUR",
    "date": "2022-22-22",
    "rates": {
        "AUD": 1.5532,
        "BGN": 1.9558,
        "BRL": 3.8403,
        "CAD": 1.5024,
        "CHF": 1.1613,
        "CNY": 7.7881,
        ...
        "USD": 1.1848,
        "ZAR": 16.441
    }
}

The regular expression extractor will set "base = EUR".

The picture below shows you how to define a variable as part of an extractor post-processor:

⇒ Define Variable as Part of BeanShell

⇐ Define Variable as Part of Test Plan

⇑ Variables and Functions in JMeter

⇑⇑ Apache JMeter Tutorials