How to deal with the test data in Junit?

Question

In TDD(Test Driven Development) development process, how to deal with the test data? Assumption that a scenario, parse a log file to get the needed column. For a strong test

Answer 1

Hard code them in the tests so that they are close to the tests that use them, making the test more readable.

Create the test data from a real log file. Write a list of the tests intended to be written, tackle them one by one and tick them off once they pass.