Monday. Disappointed to discover the coding dojo cancelled. Guessing that not enough people knew what it was and were not prepared to sign-up beforehand. Sat in instead on Scott Meyers’ ‘Better Software – No Matter What’: familiar material by a good presenter. Sofware quality depends on programmers, and how they exercise their discretion in implementing requirements: providing guidelines makes a significant difference. Insist on useful requirements. Create interfaces that are easy to use correctly and difficult to use incorrectly. Use design by contract to specify requirements using pre-conditions, post-conditions and invariants. Embrace static analysis. Favor constructor parameters over singletons.
Lunchtime presentation by Robert Martin, giving some inside history on Agile and Scrum, and how that has led to today’s movement for software craftsmanship.
Afternoon session on easyb and Groovy with Rod Coffin and Andy Glover: slow start before plunging into use of the requirements domain specific language with IntelliJ and Eclipse. Tested and documented version of a LIFO stack implemented with remarkable speed.
Evening discussion panel on SOA: a marketing buzz phrase past its prime. SOAP/HTTP web services remain the most robust solution even though simpler RESTful solutions have gained popularity on more ‘primitive’ platforms.
Finally an informal presentation by an engineering director and architect from LinkedIn describing their infrastructure and development practices. Tomcat, a custom MVC framework and JSP compiler, SpringRPC (~100 services), Jetty and Oracle on SPARC. Four million visitors a day peaking at 200,000 concurrent users. Originally pair programming but now simply at least two developers per project. No contractors, all 100 engineering staff in the same building. High end Mac workstations and laptops with Eclipse/IntelliJ. 1,500 JUnit/HttpUnit test cases for ~1,000 KLOC automated using Hudson. Database partitioned both vertically (by functional area) and horizontally (by member id range). Back to the hotel past 9pm.
Tuesday. Morning session Dean Warner on programming in Scala, a scary-powerful collision of Java and Lisp/Erlang used by Twitter for higly parallel message handling. Afternoon session with Chris Richardson, author of ‘POJOs in Action’ giving a technical introduction to Spring Framework dependency injection (replacing singletons with constructor arguments) enabling Spring AOP for service methods. Also Spring JDBC and Hibernate, all using either XML or annotations.
Wednesday. After two days of half-day tutorials the conference format switching to four 90 minute workshops per day plus lunchtime presentations. Website navigation using menus and search, especially for e-commerce. Overlay menus at Amazon. Everyone familiar with the layout of Outlook. BabyNameWizard.com making novel use of AJAX. Neal Ford with an introduction to Ruby and JRuby, an interpreted language well suited to metaprogramming such as building test frameworks including Mocha. Robert Martin walking through some of his code from FitNesse: functions should be well named, short, and do one thing only. Two presentations from Scott Ambler on Agile development: delivering code early and often, using TDD, involving stakeholders, building self-organizing teams and delivering what the customer wants. Geographically dispersed teams with a 15% higher rate of project failure: fly people around or pay more in hidden costs. Evening awards ceremony: Dr. Dobbs Excellence In Programming award going to Scott Meyers and over a dozen Jolt awards made in surprising haste, including easyb. Reading the first chapters of ‘Groovy In Action’.
Thursday. Morning sessions on how to select a web framework and testing web applications. Grails immature and questions still over the Groovy classloader. GWT-Ext and Tapestry 5 or Wicket a recommended configuration. Rod demonstrating unit and component testing tools, including infinitest, WicketTester, HtmlUnit and Watij. Lunchtime presentation from Juval Lowy on the coming boom in power management software for homes, electric vehicles and buildings. Afternoon sessions on Guice, a lightweight dependency injection framework, and using the new javax.script package in Java 6.
Friday. Morning sessions on Spring 3.0 and Continuous Testing. Spring Framework clearly mature and featureful. Rod demoing intellitest IDE plugin allowing all dependent unit tests in a project to be run automatically whenever class bytecode changed. Afternoon sessions on xUnit testing and generating documentation during the build cycle. Dependency injection does not require a framework for in-house applications. Creating and maintaining mock objects for database services may be impractical, consider the Dependent Object Framework and possibly H2 instead. Demos of Hudson and Doxygen rounding out the conference.
What did I get from the conference? Most inspriring was seeing Rod demonstrating TDD in action with a hands on pair programming session and discussions of the supporting tools. Scott Meyers, Robert Martin and Scott Ambler reinforcing the importance of TDD in the bigger picture, Justin Gordon describing use of TDD on a significant IBM project. Automated testing driving the adoption of dependency injection frameworks such as Spring and Guice. A second significant theme was scripting languages – including their use for testing – with sessions on Groovy/easyb, JRuby/Mocha and Scala. Finally there were the demos and pointers to projects like GWT-Ext, Hudson and Doxygen worthy of further investigation.