Tuesday, April 07, 2009

JBoss EJB3 tutorials and docs

I thought i will blog this, since i have been seeing many of the community members looking for some documentation or tutorials for EJB3 on JBoss. Obviously, for anyone who's trying to learn a new technology, the best place to start will be the tutorials. Many of you might be already aware that the new JBossAS-5.x series have been released to the community. Just recently we uploaded a completely new set of EJB3 tutorials and reference documentation targeted for JBossAS-5. These tutorials and reference documentation is available here. The earlier set of tutorials which are targeted for AS-4.x are available here.

The new set of tutorials have been modified to work against AS5. The changes mainly include changes to deployment descriptors or any JBoss specific EJB3 features. The complete source code for the tutorials is available for download at the same URL.

The important point to note is that these tutorials will be maintained to work against the latest release of EJB3 plugin. So what is EJB3 plugin? JBossAS-5 ships with EJB3 support by default. As you all know, the JBoss EJB3 project and the JBoss AS project are maintained separately and as such have their own release cycles. So what happens if we introduced something new in EJB3 or do a major bug fix for the community in EJB3 project? How do we make it available to the community who use EJB3 support provided by AS5? That's where the EJB3 plugin comes in picture. The EJB3 plugin provides a mechanism where you can patch newer versions of EJB3 into AS5. This way, if there are any major bug fixes or enhancements you are waiting for from the EJB3 community, then you can use the EJB3 plugin to patch it in AS5.

The next question would be, when and where do i get the EJB3 plugin for the AS. EJB3 project has come up with a release cycle where, every 2nd and 4th Friday of the month there will be a EJB3 release. These releases are downloadable at the JBoss EJB3 download page . So how do you use this plugin against the AS? It's pretty simple. All you need is:

- JBossAS-5 installation
- Ant 1.7

Download the plugin which is nothing but a jar file and run the following command

java -jar jboss-ejb3-plugin-x.x.x-installer.jar < path to JBossAS5.x >

Note that jboss-ejb3-plugin-x.x.x-installer.jar is the name of the jar file you downloaded.

So that gives you an idea about what the plugin is. Coming back to the EJB3 tutorials, I mentioned earlier that these tutorials are maintained to work against the latest release of EJB3 plugin. What this means is, you won't find a tutorial in a broken state (tutorials that are no longer running). The tutorials are tested against every release of the EJB3 plugin. So if something in the tutorials breaks, then that's fixed at the right place before they are released to the community.

If anyone has any suggestions or questions about the tutorials or the EJB3 docs, feel free to start a discussion in the JBoss EJB3 forum

1 comment:

Anonymous said...

The best treatment on JPA that I've seen is over at OpenJPA. The documentation adheres to the spec so it is applicable across vendor containers. http://openjpa.apache.org/documentation.html