Thursday, March 13, 2008

A Random Walk Down NFJS Street

Here are a collection of thoughts (and useful references) from the recent NFJS Gateway Software Symposium.

See my other posts for my motivation, background, and disclaimers. In brief, I'm a 7-timer and enjoy these intense weekends.

Groovy and Grails

I didn't see many Groovy or Grails talks. I'm a fan of both, but I know Groovy and I've seen enough of Grails to know that I need some "flight time in the cockpit" more than another session.

But make no mistake: these topics were a big part of the conference. Many sessions in the 'G-space' and a lot of buzz among the audience and the speakers.

Did you know: the literature has caught up to Groovy's frenetic pace. For an introduction, see Programming Groovy by Venkat Subramaniam. For a how-to manual, check out Groovy Recipes by Scott Davis. Both guys are top-shelf, entertaining speakers on NFJS.

For Grails, how about this for a summer blockbuster: the 2nd edition of the Definitive Guide to Grails.


I went to a good session on Transaction Design Strategies with Mark Richards. Essentially, he would assign an ownership role to a given tier (e.g. the client) and then the transactional responsibilities logically followed from that.

For example, if the client assumes the role of ownership, and the system uses declarative transactions, then one can annotate a service layer with MANDATORY. In fact, it is probably an error if the service layer is not designated as such, with this particular strategy.

Interesting stuff. During the session, I couldn't help but wonder if one could use a static-analysis tool to check the annotations by logical inference, for a given strategy. It would scan a section of the codebase, producing appropriate warnings for transaction declarations (based on the strategy indicated). Think of FindBugs -- for transaction boundaries. Is there such a thing?

Mark has a book available via free PDF at InfoQ.


One bolt-of-lightning session was on YSlow by Scott Davis. The quote of the day, by Scott:

  • YSlow doesn't tell you that your website sucks: it tells you why your website sucks.
In short: download Firebug. Then download YSlow. Point it to a URL and check out the advice. If you need more, check out this book or check out Scott's fantastic talk.

Afterwards, you will point YSlow, like a cosmic xRay gun, at every website you ever worked on. If you have moved on from the project, you will laugh -- nay, cackle -- at the ridiculous last-minute demands placed by the marketing department and the consequent slow-down.


I caught a cool talk by Brian Sletten on the Restlet API. It's a framework/API from the RESTafarians. Really slick. Check out the Uniform class in the Javadoc. This is not only a brilliant pun (on the insistence of strict RESTies for a uniform interface) but a microcosm of the REST spirit. It inspired this thought:
  • Programs on a Turing machine boil down to a handful of actions. In REST, protocols boil down: the opcodes for a given web service ends up as a grand orchestration of simple GETs, PUTs, DELETEs, etc. That Uniform class is REST distilled.

The Keynote

I mentioned the presentation by Scott Davis in an earlier post: How to Lie with Open Source. Very entertaining, thoughtful, and an object lesson on a good keynote, in terms of dynamic presentation and cadence.

In StL, we saw the premiere: watch for it coming to a city near you.

The Panel

It is impossible to re-capture the spirit of a NFJS panel. Irreverent and funny.

Some themes were: tremendous collaboration on the language front (even among Sun and Microsoft), concern for the fractious debate in Java 7, and some tired (IMO) showdowns between Eclipse and Idea.

I remember 2 books that were highly recommended: Flow and The Riddle. On my list.


Due to session conflicts and having seen some talks previously, I missed several favourite speakers and barely caught Ted Neward.

The Scala talk was a good fit: a chance to hear Ted and continue the Scala theme after an excellent JUG presentation by Tim Dalton.

I was mostly interested in Scala's concept of Actors (for concurrency), but some lights went on this time around. I didn't realize just how functional Scala is: I was always focused on its static type inference (versus Groovy and jRuby). This language will stretch you, especially if you're only familiar with Java and its ilk.

As Ted says, this is a "different breed of cat". For more info, check out his "Busy Java Developer's Guide" series.

Quick Notes
  • I saw one talk on Groovy: a DSL session. It is amazing how un-Groovy like the DSLs can be now, with the high-powered dynamic mojo in Groovy 1.5.x. However, I think that ANTLR is tough to beat if the DSL is high-profile and used by non-developers.
  • I saw a session on JMS. I suspect this is one of the most underrated pieces of Java EE. It is really strong stuff! Naturally, being a Groovite I wondered what the examples would look like in Groovy. Stay tuned. I swear, there is an entire cottage industry in taking Java examples and implementing them in Groovy.
  • There were two sessions on Terracotta: an intro and one on caching with Hibernate. I had seen one and am planning on seeing the other at the St Louis JUG (see previous post). If you haven't seen it, come check it out. The wow factor is high.
  • A session on OSGi opened my eyes to that space. There are no books or classes on it per se, but versioning is one timeless mofo of a problem for computer science. In brief, my take on OSGi is that it is as explicit and demanding as the classpath is implicit and subtle: but for versioning, that's what you want.
  • The Birds of a Feather on Dynamic Languages was great fun... A lot of people were new to the game. In the BoF, but also in general, there was some anxiety over "which language should I learn, given finite resources?". That's a tough call. I am partial to Groovy, but as I write this, my answer is: it doesn't matter. It is more important to get in the game with one of them than to sit back and wait on the sidelines. Even if you pick "wrong" the experience can transfer, to some extent, over to any future languages. Just experiment and have fun!
The Upshot

Another winner: I'm still tired from the brain exercise and from being engaged for 2 1/2 days.

Stay tuned for some more thoughts from the show. I hope to work out some exercises of some the technology.

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