Is it bad practice to include properties/configuaration files within jars?

Question

For example:

MyApp is a web app that contains a properties file (server.properties) that describes config data (e.g. server names) for the app. In the development phase

Answer 1

I use property files in webapps (WARs), but mostly for default values and stuff that's more or less immutable (since webapps shouldn't be updating their WARs even when they can).

For stuff like what you're talking about, however, I use JNDI. You can define the properties as resources in your web.xml file. That way, at worst, you update web.xml and not the app itself.

For some servers there are ways of overriding these resource values without touching the WAR at all. For example, in Tomcat.

I normally make one WAR for test, Q/A and production and override the environment-sensitive resources in exactly this was, using Tomcat's Context xml files. I consider this a lot better than having to build multiple WARs or to modify WARS, since the app I'm testing is almost identical to the app that's in production.