However, I think this is pretty difficult to do unobtrusively with Java. The Rails people have pretty much solved this problem... it uses the unjoined/uncompressed files for development and then it compresses everything during production. It does this unobtrusively as you don't have to change your html headers or anything like that - it works for both testing and production. This is more or less what I want. Does it even exist in the Java space?
At the same time, if I'm going to package up my war for production, I want it to use the joined and compressed files instead.
Is this even possible? If so, what tool should I be looking at? I know there are quite a few that do some of this, but they've fallen short on the "unobtrusive" aspect.