I am new to Jmeter and have been struggling to get it working to test my POST API. It works fine for a GET API call where I pass the parameters through the Parameters tab.

Details here:

server name: localhost port: 8080 path /registerMobileUsingCode

In the request body, I am sending the following:

{ "clientName": "DemoOrg", "code": "9880007615", "languageId": "1" }

My Jmeter setup looks like this:

And my HTTP Request Header looks like this:

The API is in production and works fine with postman.

I am just unable to get it working through JMeter. It is obvious that I am doing something wrong but can't figure out what despite having spent a considerable amount of time Googling for solutions.

Any help would be much appreciated.

UPDATE - 1 - Updated with jmeter log as suggested

Thread Name: Thread Group 1-1 Sample Start: 2017-08-09 17:03:41 IST Load time: 1604 Connect Time: 1525 Latency: 1604 Size in bytes: 399 Sent bytes:251 Headers size in bytes: 213 Body size in bytes: 186 Sample Count: 1 Error Count: 1 Data type ("text"|"bin"|""): text Response code: 500 Response message: Server Level Exception encountered

Response headers: HTTP/1.1 500 Server Level Exception encountered Date: Wed, 09 Aug 2017 11:33:43 GMT Access-Control-Allow-Origin: * Content-Type: application/json Transfer-Encoding: chunked Server: Jetty(9.2.16.v20160414)

HTTPSampleResult fields: ContentType: application/json DataEncoding: null

UPDATE-2 - Using Postman and JMeter Recorder

As suggested by @Dimitri T, I downloaded the Linux version of Postman and started it with --proxy-server=localhost:8888.

I was now able to make a Postman request and capture the request in JMeter. Here is what the request looked like:

Jmeter capture of a Postman Request

As you can see, nothing radically different from what I did. However, this DOES work! So hurray!