What I typically do here is use Spring Profiles. To make this work you just make sure to set spring.profiles.active variable in your environment somewhere (JNDI, System variable etc), when Spring picks it up it uses it initialize the correct profile.
Or if you aren't using Spring 3.1, Maven has a concept of profiles too. And anything you put into the resources directory will get copied into your classpath. So a Maven profile approach is to create a directory for each profile in your resources directory. In each directory has your properties file, and in this case it would be best to give it the same name in each directory. Then in your Spring config you just use that one name. When you run your maven build you set your profile to one of the profiles and it will copy out the file from the correct directory. Each directory might ahve to have the exact same name as the profile, or some setting in your pom or better settings.xml for Maven pointing to the corresponding directory in resources for each profile.
Or you can also use Spring Expression language to dynamically point to the correct file. (A little more complex)