A very full first day is in the books. Here we go…

Sun keynote

The conference officially kicked off with the 2-hour “Sun General Session.”

  • F3 gets rebranded as JavaFX, but will people in the Silverlight and Flex camps even give it a thought?
  • JRuby’s getting a whole lotta love from Sun. They specifically called out JRuby in at least two instances (including official support for it in Glassfish V2).

On to the tech sessions…

Cool Things You Can Do With the Groovy Dynamic Language

Presented by Guillaume Laforge (Groovy Project Lead) and Dierk Koenig (Lead Author of Groovy in Action)

  • 600 people + a waiting list
  • Called in “air traffic controllers” to guide people into the room
  • Dierk: “Kind of like saying, ‘Please tell me everything you can do with Java. You have 60 minutes.”
  • Good demoes on how Groovy eases many of the pain points and eliminates much of the noise in day-to-day Java development

I also had the privilege of sitting next to Alex Tkachman (from JetBrains) during the talk, and I got to see a quick demo of the up-and-coming Grails plug-in for IntelliJ IDEA v7. To those of you calling for better tool support for Groovy and Grails, suffice it to say that your voice has clearly been heard.

Java Puzzlers, Episode VI: The Phantom-Reference Menace/Attack of the Clone/Revenge of the Shift

Presented by Josh Bloch (Chief Java Architect at Google and Author of Effective Java) and Bill Pugh (Professor of Computer Science at the University of Maryland and founder of FindBugs)

  • Huge room. Slam-packed. 1000 attendees? 1200? Huge.
  • We should all study the presentation skills demonstrated by Josh Bloch and Bill Pugh. These guys are true rockstars.
    • Solid, polished speakers
    • Somehow able to explain tedious features of Java, and do so in a way that’s fun and, at times, downright hilarious
  • Presented the “moral” of each puzzle
  • FindBugs already identifies each and every one of these evasive corner cases of the Java language:
    • “The Joy of Sets”
      • Sets + generics + some hidden gotchas
      • Moral - Avoid short types. (Primitive types that is, not midgets.)
    • Goodbye, URL
      • In java.net.URL, [hashCode](http://java.sun.com/j2se/1.5.0/docs/api/java/net/URL.html#hashCode() and [equals](http://java.sun.com/j2se/1.5.0/docs/api/java/net/URL.html#equals(java.lang.Object) are over-engineered and, as a consequence, they happen to be broken.
      • Moral - Use URI. (Avoid URL and over-engineers.)
    • JUnit vs. Threads
      • JUnit doesn’t support testing concurrency.
      • Moral - Working software leads to currency. ;-)
    • Recursive Initialization vs. Auto-unboxing
      • Yes. We’re deep in Geektown now. Good stuff.
      • Moral - Create the Singleton instance after all static field initialization statements.
    • Low-level Bit-twiddling with java.io
      • [java.io.InputStream#skip](http://java.sun.com/j2se/*5.0/docs/api/java/io/InputStream.html#skip(long) is darn close to evil
      • Morals
        • Ignore return values at your own risk and peril.
        • For API designers:
          • Don’t violate the principle of least astonishment.
          • Make it easy to do simple things. (If only there were a language that followed this mantra out-of-the-box.)
    • Fun with Math.abs
      • Integer.MIN_VALUE == -Integer.MIN_VALUE
      • Moral - [java.lang.Math#abs](http://java.sun.com/j2se/*5.0/docs/api/java/lang/Math.html#abs(int) doesn’t guarantee a non-negative result.
    • Ternary Operator vs. Numeric Values
      • Using mixed numeric types with the ternary operator can be a recipe for trouble
      • Moral - : ? is not always equivalent to if/else

Open-Source Licensing Emergency Room Panel

Presented by Simon Phipps, Cliff Schmidt, and Eben Moglen

  • Interesting state-of-the-union on the various open source licensing philosophies and plans for avoiding an influx of new license models (presumably all offering slight variations on existing licenses)

Integration Gets All Mashed Up: Bridging Web 1.0 and Web 2.0

Presented by Andreas Krohn

  • Defined a mash-up as the “the ad-hoc assembly of situational apps”
  • Made the case for mash-ups as an enterprise solution (to provide access to disparate systems with conflicting or non-existent APIs)
  • Discussed the enabling technologies behind the mash-up phenomenon (and some standards that may come into play in the future)
    • Atom vs RSS
      • No compelling reason to continue supporting RSS
      • Atom is a true standard (as opposed to the 13-ish flavors of RSS)
      • Atom can carry payloads other than plain text (e.g., binaries)
    • Atom Publishing Protocol (APP)
      • Supports REST, user authentication, etc.
      • Example: Google Data API
    • JSR 311 - Java API for RESTful Web Services
    • Tools to check out
      • Feed43 - Produces RSS feed from any web page
      • openkapow - Kinda like OS X Automator for slicing and dicing websites to produce web services from them
  • Makes for cool demoes and certainly has several practical uses, but the model just seems too fragile for corporate use. Would you honestly want to support an app that fetches its data via the web equivalent of screen scraping and assumes that the underlying web page (whose author you’ve never spoken to) won’t change its structure?

JetBrains “BoF”

You won’t find this one on the session schedule, but it was by far the highlight of the day. This “mash-up” of the Groovy & Grails guys, NFJS guys, and JetBrains guys was the sort of ego-free exchange of ideas that progresses our industry. Many thanks to the kind folks at JetBrains for putting together this event. Well done!

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Day 2 starts in 2 hours. Stay tuned.