JSR223 Tips and Tricks Part 1

You can script using multiple languages within Jmeter.  Beanshell and Groovy both run lightning quick and are 99% (or thereabouts) compatible with standard java syntax.  Both languages can be utilized inside the JSR223 Post Processor.

In this tutorial series I will demonstrate some tips and tricks that will help you manipulate data for API testing with Jmeter.  I am assuming that you are already somewhat familiar with Jmeter and Java.

First create a new Jmeter script and add a UDV to intialize the variables.

${Server} = This is the main URL of the web service
${Protocol} = Communications protocol

Setup the Test Plan in Jmeter as follows:

• Create a Thread Group.
• Create an HTTP Request.
• Select GET in the Method dropdown.

• Add an HTTP Header Manager to the HTTP request.
• Add three JSON Path Post Processors to the HTTP request.
• Add a JSR223 Post Processor to the HTTP request.

When finished, you node tree should look something like this:

The response is expected to be in JSON format, so the Content-Type and Accept should both be set to “application/json”.  Configure the Header Manager as follows:

We are going to run a GET request against the public Star Wars API.

The GET request should look like this (Body Data is blank in this request):

Use the JSON Path Post Processors to easily scrub the response for specific values:

Inside the JSR223 Post Processor under the GET request, select Beanshell in the programming language dropdown and paste the following code in the script box:

//get extracted values from vars created in JSONPath Post Processors
String extName = vars.get("name");
String extBirth = vars.get("birthyear");
String extHome = vars.get("homeworld");

//get response from prev sampler
String getResponse = prev.getResponseDataAsString();

//print response data to log
log.info("\n" + "Extracted name => " + extName + "\n" +
   "Extracted birthyear => " + extBirth + "\n" +
   "Extracted homeworld => " + extHome + "\n" +
   "Entire GET Response is:" + "\n" + getResponse + "\n");

This should print the following to the log viewer:

To see the entire reponse in JSON format, add a View Result Tree listener to your test and select JSON next to the Response Data tab.

What did we do here ?

1.  We used the built-in JSON-Path extractors to do the dirty work and get three specific values that we need from the response.  This can also be accomplished by writing code inside a JSR223 Post Processor.  Instead we used built-in extractors, so there was no need to import any libraries or write any extra code.
2.  We used Correlation to store extracted values in variables that can be accessed at any point inside the thread.
3.  We passed the extracted values into the JSR223 Post Processor and printed them inside the log viewer.  These values could just as easily be written to a text log file or a CSV output file.
4. We used the prev variable to get the entire JSON response as a string.