JavaOne, day 3.

So, the third day of JavaOne has also featured some interesting presentations. My blog today will not be a blow-for-blow description of these, but more a few interesting tidbits I noticed during the day.

I managed to talk to Gilad Bracha about how I thought his proposal for super packages looked very inspired by Common Lisp packages, and his response was that it was an interesting observation. He hadn't thought that way consciously until I pointed it out, so it was not designed that way, but he said that it was a good sign for the proposal that it looked like Common Lisp packages.

Actually, the first session was probably the most interesting from my perspective. This was Gilad s talk about supporting dynamically typed languages on the JVM. The first part talked about invokedynamic, which is fairly straightforward. The only new information I got about this area was that they're thinking about adding handlers for cases where the JVM can't discern a correct overloaded method to call for a dynamic invocation. In reality, this would more or less be a method_missing, available directly on the JVM, with all the performance characteristics you can get from the JIT. Nice stuff. Probably the handler architecture could also be used to implement some variations of multiple inheritance and mixins, which also is a problem to do efficiently on the JVM.

The second part of his talk was about hotswapping, which I didn't even know they're trying to get into the JVM. Basically hotswapping is what enables eval and replacing, adding and removing methods and types at runtime. This seems to be a very hard problem, but Gilad had some ideas, so it looks promising. It seems that JRuby may actually be able to run completely in JVM bytecode sometime in the future. Very cool.

After this I want to a session about simplifying enterprise development with scripting. This turned out to not match the title; it was basically another presentation on Groovy, and nothing much more.

The session on Compiler Optimizations where really interesting, and full of the kind of vocabulary that makes your head spin (but for different reasons if you're a compiler head or just a regular geek).

The Harmony session where really cool, they actually have a working (but slow) Swing implementation. The demonstration showed JEdit running inside Harmony, which is nice.

The security traps session was mostly basic material. Nothing new at all if you've been reading the books.

The last session for me today was about good ways to both an enterprise application. This presentation was really great, one of the top 3 this JavaOne, and I'm definitely planning on going home to study the slides. (It was TS-5397 if anyone wasn't there). Great stuff, really.

So, the rest of the evening will be After Dark Bash, and then out to make San Francisco unsafe.