What is the proper way to handle properties files based on the environment you are building for?

[Frank Russo]

I'm building a webapp. Our webapp depends on some environment specific
variables that are defined in a group of properties files. Depending on
the environment I want to build for, i.e., dev, qa, prod, I build the
war as follows: mvn -Denv=ENV_VAR clean package.
 
Our package structure for the properties files is: 

        src
        |
        ----main
            |
            ----resources
                |
                ----dev
                    |
                    ----*.properties
                |
                ----qa 
                    |
                    ----*.properties
                |
                ----prod 
                    |
                    ----*.properties

Depending on the value of -Denv=ENV_VAR, (e.g. -Denv=dev), the proper
grouping of properties files get put into my web-inf/classes directory. 
 
Is this the proper way of doing this, or is there another way? The
reason I'm asking is that, say someone does a build forgetting to add
this. Then the build will still work, except that all files, including
the folder structure, are added to the war without warning. This
probably won't be caught until we deploy the app.
 
Thanks...
Frank Russo
Senior Developer
FX Alliance, LLC