If I put an EJB 2 in an application server under JavaEE 7, will it run?

[Ferdinand Victorinus]

I'd like to know if an EJB 2 runs in an application server under JavaEE 7.

[William Markito Oliveira]

Hi! It actually depends on the container. As far as I remember, OC4J and WebLogic were both capable of understanding deployment descriptors (DDs) for both versions EJBs 2.x and 3.x. I made a post on my blog about it for WebLogic 10.3.4 (http://wmarkito.wordpress.com/2011/01/19/java-standards-in-weblogic-10-3-4/)

Although we highly encourage someone to migrate as the API is much more simpler and since you'd be upgrading your container and probable redoing all your tests with the EJB 2 app, it would be almost the same time you'd need to migrate from EJB 2 to EJB 3.

Here is a link to some migration tips, still based on OC4J but most are general guidance for EJB2xEJB3 migration. http://www.oracle.com/technetwork/middleware/ias/oc4j-twp-ejb3-migration-1013-133021.pdf

Also note that this migration generally means delete lines of code & configuration files, which is really nice and easy.

Thanks!

[Rob Spoor]

If I recall correctly, JEE 7 no longer requires containers to support EJB 2. Whether or not it works depends on the container.