I want to read the request message from a file in JMeter. How can I do this?

Assume that you need to do a load test with a request which is in a file. Assume you need not to copy it to JMeter, you need to read the request body from a text file and do the POST operation.

All you have to do is, use the below command instead of the POST body.

${__FileToString(large_message.txt,,)}