You probably know about JRebel already - it’s a commercial product that dynamically reloads Java classes without having to redeploy your webapp. Not necessarily the cheapest of products, but if you’re a full-time dev working on the JVM, then it can easily pay for itself. Oh, and it’s free for use on any hobby/open source projects.

JRebel itself is pluggable, and so for a while now I’ve been meaning to work on an integration with Apache Isis. Actually, invalidating Isis’ metadata caches is pretty easy, the difficulty really arises in Isis’ JDO/DataNucleus objectstore.

But, with a bit of experimentation, I’ve got what I think is a workable integration going, full details up on github.

And if you just want to see what this means, take a look at this screencast (also available on the the Isis website):