Is it a good practice to include lower environment server details property files in a jar?

This is my second post and its for a friend.

One of my friends teammate opinion is that they should include the Server details properties of all the environment in the separate property files and include all of them in the final jar that going to production. Also he is of opinion that the jar should identify environment dynamically from hostname and read from the corresponding property files. For me, this appears absurd and have never heard of such a thing earlier. I'm of opinion, that only one property file should exist in this case and we have to modify the property values at the time of application deployment.

Kindly tell me, which is the right way to do it. I never heard of such a method earlier.

Thanks in advance.