Adam Bien's Weblog
JavaONE EJB 3.1 - even better than the real thing :-)
JavaONE Outtakes:
Some interesting features of the EJB 3.1 specification:
- Local interfaces are optional now, we still need @Remote (which is good)
- EJB-Jars are optional - session beans can be deployed into a WAR-file - but are still independent
- Singleton beans (with new @Singleton Annotation): not intended to be a cluster-wide singleton, but the state is shared in the whole application
- Singletons can be accessed in @ReadOnly mode - a hint to container to optimize the access
- Singletons can be accesseed in @ReadWrite mode as well
- BMC (Bean Managed Concurrency, or @BeanManagedConcurrency) will be available. In this case the developer is responsible for synchronization - so usage of synchronized keywords etc. is allowed in that particular case
- Timer Services will be extended to CRON like functionality. Timer could be registered automatically using an annotation.
- @Asynchronous annotation can be used to mark methods (of a stateful session bean) which will be executed asynchronously.
- Stateful Session Beans could be also exposed as a WebService - so stateful WebServices will be supported.
EJB 3.1 makes EJB 3.0 even leaner and better. I only miss the standardization of JNDI-names - but this JSR spec was not even started, so there is still hope...
Posted at 04:51AM May 09, 2007 by Adam Bien in Java / JEE / Architecture | Kommentare[2]
[This entry is based on / extends my books: Enterprise Architekturen, Leitfaden fuer effiziente Software-Entwicklung and: Java EE 5 Architekturen, Patterns und Idiome]



Hi! thanks for the points! Nice meeting you as well - eventhough I had to leave at 9 :P! I have to admit though from all the above points I am a bit ..concerned regarding the bean concurrency addition. Its like Pandora's box, if missused could end up to a disaster for any j2ee application!
greetings from Greece!
Gesendet von Paris Apostolopoulos am May 15, 2007 at 05:03 PM CEST #
The timer service CRON support is something to look forwards to, though in my view even more attention should go to what I call 'lifecycle of business entities'. See my blog at for more on this topic.
Gesendet von Frank Cornelis am May 18, 2007 at 10:36 AM CEST #