JAOO 2008, Tuesday

Today, at JAOO, I attended sessions related to architecture, REST, and network databases.

For the record, I should state that I have strong distaste for the software architecture / architect terms. In my opinion, software architecture is a muddy buzzword, just like the architect title seems to cover a suspiciously broad category of profiles (Buzzword manager? Very experienced developer? Software development project manager?) I remember a recruiting conference where a company was hiring graduates for architect positions; if the architect title can include people without any experience at all, then it's void of meaning. Anyways, one should be open minded, so I decided to attend selected talks on the architecture track.

Frank Buschmann held a talk about architecture reviews. Buschmann has several good points, although they would probably hold for just about any review situation. A point was that an architecture reviewer should keep a neutral approach towards the development team; this certainly sounds like a good idea. <rant>However, one of Frank's war stories included a tale of how he had once used a special strategy to convince a team that they should stop being critical about a development framework which had been forced upon them. Is that being neutral?</rant> Performing an architecture review sounds like a good way to ensure documentation which would probably never be written otherwise; for this reason alone, it's probably recommendable.

Another architecture talk was Top Ten Software Architecture Mistakes by Eoin Woods. Woods seems to subscribe to a definition of a software architect which is much akin to a project manager who knows about systems development. The talk was a very well performed live version of an article which Woods has written. Too bad there wasn't time for discussion (a general problem with JAOO's presentations); but it would probably have been hard to handle anyway -- the large room was packed with people.

Eberhard Wolff held a two-part talk about Java History and Outlook. I attended the second part, which was a rewarding experience. Wolff gave several examples of how community initiatives have outlived certain over-designed "official" J2EE components. He also made an interesting point of how the Java world's web application trends seem to move from MVC towards component-based desig -- while, conversely, .Net is currently sliding from component-based design towards MVC. Wolff's company is involved in the Spring framework; if I'm not mistaken, it sounds like the Java world may finally be cured of its "frameworkitis" and converging on Spring for modern Java-based web applications. Although Wolff obviously has a strong interest in Java, the talk wasn't an evangelism event: He pretty much declared Java dead on desktop. And he noted that while the JVM is doing fine, the Java language has trouble incorporating new, needed features; instead, JVM based languages like Scala may take over in the long run. Until then, Wolff strongly suggested adopting aspect oriented Java add-ons such as AspectJ and Spring AOP to gain more expressiveness.

I had the pleasure of attending two good talks about REpresentational State Transfer (REST): Ian Robinson's RESTful Enterprise Development and Stefan Tilkov's Successfully applying REST - Integration, Web-style.

Tilkov presented a rigorous definition of REST, but in a nutshell, REST is web services, done right, IMHO. Unlike over-designed and obese SOAP, REST doesn't abuse the HTTP protocol; instead, REST takes advantage of URLs, MIME-types and HTTP's basic operations/verbs (GET/HEAD, POST, PUT, DELETE) to offer surprisingly powerful, yet simple, solutions. Other HTTP features, like content negotiation and caching, make REST even stronger. (On a side note, Tilkov pointed out it's a shame that HTML doesn't allow PUT as a form method; HTML 5 should fix this, however.)

After a good, basic explanation of REST, Tilkov went through a number of patterns and anti-patterns which one should be aware of. One interesting suggestion was to always provide an HTML representation, in addition to the main MIME type of a URL. Sort of like Java's toString() method which can be performed on any object type. That way, it's easier to perform tests.

Robinson's talk described a case where a legacy system had been integrated with new solutions, using REST. Specifically, Atom and AtomPub were used to enable the new solutions to efficiently pull messages and data from the legacy system.

In the late afternoon, a number of BoF sessions were held.
I'm always skeptical when people propose something as "post-relational", keeping in mind how the relational databases actually took over after the network databases way back then. But one needs to have beliefs challenged sometimes, and I really like BoFs as a supplement to traditional talks. So I attended a BoF about graph databases, led by Emil Eifrem. Emil's company have created an embedded database for Java which is good at storing nodes and edges and traversing them. The database -- called Neo4j -- is allegedly the fastest of its kind in the Java world. Neo4j is GPLed and offers transactions; nice. I can certainly think of use cases for navigational databases, but I didn't leave the meeting with an urgent need to take a closer look at the product. It seems that there are no standards for network database queries, and most (all?) of them tie you to one particular development platform, leaving you to have to expose web services if other platforms must have access. At the least, I would see if recursive SQL could be used before I went for a network database.