JEE 6 patterns – the server side java symposium

As of Websphere 8, all major app servers support J EE 6 except one that I hadn’t heard of. Adam Bien got a number of jabs in at Rod Johnson’s comment that NetBeans isn’t prevalent.

Many patterns are gone from earlier versions of JEE including this list. Amazing how much content was discussed on one slide.

  • most interfaces – Adam mentioned another valid use of interfaces – reuse. Also noted the IXXX or XXXImpl are signs that the interface isn’t needed.
  • DAOs – should be able to state the reason if have. To avoid duplication have a service with a business name. for example OrderSearchService
  • DTOs – duplication across layers. And if you use a mapping framework like bean utils, you aren’t really decoupling. It is useful to do create a DTO when you don’t have control over the underlying object. Similar reasoning to interfaces. A good metric is whether every layer is affected for a feature request
  • ServiceLocator, Factory – use injection
  • Business Delegate – just delegates to ejb, for handling exceptions
  • Session Facade – needed to wrap CMP because didn’t work well
  • Value Object Assemblers – can just create aggregate object
  • Service Activator – asynchronous support now built in with annotation or CDI events if want ti decouple
  • Publish Subscribe with JMS – for local delivery, use CDI events instead
  • Mandatory XML configuration – Repeating the whole package name in xml so hard to refactor. Adam sounds like he favors minimal XML. I asked what belongs in XML and the answer was passwords/ips. [I don’t think he meant passwords]. He did say anything that could change often.

Other Notes

  • Keep the war as small as possible to speed up deployment. try to keep infrastructure jars out of war manage versions of jars by deploying to separate tomcat if have to use third party jars. Adam doesn’t use third party jars unless absolutely necessary
  • go for convention over configuration
  • ECB – entity (jpa) control (optional cdi bean) boundary (stateless entry point decorated by aspects), way to model a component
  • see anti if campaign website for the lack of OO in JEE

I missed a bit of this presentation even though it was really good because I was getting ready for mine.

1 thought on “JEE 6 patterns – the server side java symposium

  1. The app server you hadn’t heard of is the one from SAP, a large German company that sells big and expensive enterprise software.

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