A Question to the Authors of Pro EJB 3.0

[Alexander Kolesnikov]

Dear Pro EJB 3.0 Authors,

This might be a good opportunity for me to ask a question which is rather important for me now.

I currently work for a software company building a solution on the basis of EJB 2.1. Well, Message Driven Beans are used most often, Session Driven Beans - sometimes, and for persistence we use Hibernate, with everything being deployed on JBoss 4.

What I am thinking about now is when should I start learning EJB 3. The intent of the company is to start using EJB 3 at some point in the future, but that point might be quite far at the moment. There are always a number of things to learn, so if it is not of urgent importance, I would prefer to learn something else right now, not EJB 3.

Perhaps the most crucial factor here is the set of benefits which EJB 3 brings with it. From what I have read about this new version so far, it significantly simplifies development proccess. Enterprise Beans are not required now to extend or implement anything, they can be POJOs. No Home Interfaces are required. Annotations replace XML deployment descriptors...

But let's take my case. We have already got a number of Enterprise Beans 2.1 ready and working. And frankly speaking, I do not find the development and deployment of EJB 2.1 that difficult.

So here is the question:

Should I make learning EJB 3.0 in my specific situation a Priority Number One? Does the new version bring anything good, except of relative easiness of development and deployment?

Thank you,

Alexander

[Mark Spritzler]

Well, the good news is that EJB 3.0 is backwards compatible with EJB 2.1, so you can still deploy your App in a EJB 3.0 compliant EJB container. Also, you can mix and match, so while you are converting your 2.1 stuff, your new stuff can be written in 3.0.

Also, depending on the version of Hibernate that you are using, Hibernate 3.x is Hibernate's implementation of EJB 3.0 Entity Beans. But, even if you are using Hibernate 2.x, the conversion isn't too much work. JBoss has a conversion guide on their website.

I still left your main question open for the authors to answer.

Mark

[Mike Keith]

Hi Alexander,

Great question, and one I actually get fairly frequently.

You couldn't be more right when you say that there are too many things to learn and not enough time to learn them. Everybody has to prioritize the technologies w.r.t. their own needs. I can only give a reply from my own perspective and experience as an architect for a large corporation. I tend to want to know 'just enough' about every new technology so that I can evaulate whether I will want to use it in future. When I need to make more immediate decisions then I dig down into them so that I can make a more informed decision. At the level that you are at right now, it sounds like you just need to be a bit aware of the technology. You can do that just by reading some papers about it. Here are some pointers on places to start:

EJB 3.0 Resources on OTN

EJB 3.0 Resources on Glassfish

-Mike