When you make comparison between ejb3  and other technology  like spring

there are more different between standard frameworks and non standard frameworks like injection ,pojo , Independencey, annotations,…



See this link

www.onjava.com/.../spring-ejb3.html



I see ejb3 suitable for developing enterprise  java applications

I don't know how did you understand  that this technology  is going to be replaced by the others!!!

EJB3 is new and fresh standard of JCP, besides, JBoss Seam is a powerful framework which is created based on EJB3 and JSF

apart from that, a number of powerful companies such as Google, IBM and JBoss are supporting this technology. you can find it out by reading related JSR documents.

if you don't want to learn  EJB3, whatever you replace it with will change  before you finish the book. IT is all under experiment every minute

the problem that you are spotting on is what we all are facing everyday with IT, only looking at JavaEE, it has scoped so widely that it seems very difficult to be really skilled in every aspect of it and even keeping up-to-date required passion, dedication and of course time
but generalizing a comment like that is pretty bold

if a project is based on (for argument sake) ajax or web services and after a while much more reliable alternatives are found you'll find yourself in a position of decision making

if you don't see much projects around you that are going to be based on EJB 3, its because if a project is developed with J2EE for years and is already running in the field it wouldn't seem mature to replace it with new stuff just because its new or its cool, but at the same time  you should keep up with the tech cause you might need to evolve existing projects or cope with the industry as technology  evolves

but I understand  sometime it sound a bit frustrating when you get to a point of applying EJB3 and then you figure EJB4 is on the way :)

in summary, learning it will not be a waste of time (I guess it applies to everything not just EJB 3 :) , even if in future  releases, EE looks much different from what we have now, it would be beneficial to leverage the knowledge as EE grows
but as a compliment to you, it takes a lot of courage to mention such a thing in this forum

BTW, to add one more thing, to answer  the quesiton "which technology  is suitable for developing enterprise  software?" I shall say, there is no abstract answer to that, it really depends on the criteria of the specific project, I'm not saying J2EE, .NET or even Corba might miss a functionality, but choice of either one requires proper analysis particulary for enterprise applications

Don't worry, learning something is never a waste of time.

Anything you learn, and spend time  to gain experience, will be replaced sooner or later; and the "later" cannot be more than a few years!



Long ago, people spent time to learn  assembly language.

Some people used to know Fox Pro or Pascal very well.

Some more serious ones went after C and later C++.

Did they waste their time?!



When the new generation of object oriented languages (like Java) were introduced, nothing became obsolete.

Those who knew programming (in any language) well, just migrated their knowledge.

It's such experiences that makes a guy with 20 years of experience a powerful IT knowledge worker.



Plus, the "E" in the beginning of "EJB" speaks for itself!

If it's not suitable for enterprise  development, why would they name it "Enterprise" bean?

as other say learning is not waste of time, and any thing you learn  will become absolute

EJB2 was very big and hard  to learn and use, EJB3 is much simpler and easier.
I have used EJB3 with seam (and JSF) in several projects, all of them enterprise  software, and I am very happy with it.
this combination worked well for me.

I have been in the projects that JSF,EJB3 and Seam have been the core technologies and frameworks. But I can't actually call them completely enterprise.
I don't know especially how much seam is reliable to be used in the enterprise  applications. Is it performing well out of JBoss? Has it been used some where well known like amazon or ebay,..
Also about JSF, Have you tried ICEFaces? How relaible is ICEFaces? What do you suggest?

I haven't used Seam under JBoss, so I don't know how it works under jboss,
but it works fine under Tomcat, Glassfish, OC4J and Weblogic.
JSR-299 (web beans) is getting ideas of Seam and other JSF frameworks (like ADF) and standardizing them.

the main idea of Seam is started from using EJB-3 session beans as JSF backing beans.
it is better you ignore this feature in enterprise  applications, which are going to support multiple UI technologies or you want to apply separation of concerns principle for better code quality.
there are lots of other features I don't find useful like Spring integration, that is only for helping those migrating from Spring to Seam.
but I prefer seam to other Java EE 5 web frameworks I have used.

sites like Amazon and E-Bay are extremely old and using very old technologies (both are using Java)
Seam is very young compared to these kind of sites.

I have tried IceFaces,
It is more a set of component than a framework, (although it has kind of framework internally for supporting ajax)
I don't like the Ice Faces API at all.
the design has some bad flaws, for example if you want to have multiple select in table, you have to add a boolean field to your row objects!

I like the seam features too. It is clear that is changing the future  of java world. I just wanted to know the reliability of the technology. The features are good. The architecture is perfect. My question  was about the implementation.

About your P.S, I am not asking behind any company and not because of a specific project.

I think the implementation can be much much better.
also there is a high need for more documentation. other that those 2 books already available.

I don't know what is wrong  in Seam but some times you have to restart your server to be able to undeploy your seam EAR application.

if I were in they place, I would write the core independent from JBoss specific components like hibernate, Drools and JBPM
and provide those features as extra abilities.
may be thats a good  commercial decision for them, but I don't like it.

It seems JBoss team is in hurry to get the leadership of java open sources (In the enterprise  atleast). I don't see the reliability that Apache has in its products.
But totally Seam has a good  future, Its story could be some thing similare to Hibernate and EJB3.

yes exactly, you just clicked the point!
seam suffer strongly from maturity of Apache open source,
it is more like rapid implementation of ideas,

I think when JSR 299 becomes finalized and ideas become mature,
and better implementations become available
it will become much more usable,
but even at it current state I found it more useful than other Java EE 5 web frameworks.

at version 2.0.0GA (not latest 2.0.1) most of the bugs are minor, and not much annoying.

Yes, seems like Redhat's in a hurry, real hurry. So much that all
hibernate development  resources are sucked into developing  the Seam
framework. Its been 5 months since the last hibernate release, and
guess what, the last 3-4 releases were just serious bug fixes (surely
they've done it because of their paying clients). The latest hibernate
release with some new features dates back to 9 months ago, and read
the svn activity log to see how dead hibernate is :
http://fisheye.jboss.com/changelog/Hibernate/core

may be, just may, thats because of Maturity of JPA and hibernate
hibernate has made great advances from version 2 to 3, after adopting JPA standard,
which was really merging the hibernate, toplink, kodo, castor, and other ORMs

speaking of my self, currently I don't have any serious design problem with Hibernate,
but from the time  you have introduced me Wickets,
I can't keep thinking about how could I have Inheritance in web UI technologies I use.

and about Redhat policy on JBoss,
most of stock market analysts believe that Redhat acquisition of JBoss was not successful.
it is a very bad news for people like me who are using lots of JBoss opens source products.
now I understand  why apache foundation development  process is company neutral.

most of stock market analysts believe that Redhat acquisition of JBoss was not successful.
Dear Arash
It was realy bad news for me. I suppose that JBoss is not successful so would you explain more and tell me about its weakness,
because i'm so interested in knowing about it.

JBoss was successful but Redhat was not successful in merging JBoss into it self.
it looks the problem is in difference in marketing strategies of two companies.

In my opinion, Redhat has bought JBoss, to attract Java developers to its linux platform,
and it has not special interest about JBoss products.

historically lots of mergers and acuisations have failed in IT industray, examples are:
HP and Compaq
Borland and Ashtontate (DBASE)
IBM and Lotus
I hope JBoss doesn't fall into same category.

it's more of a business plan and market segmentation. It has
nothing to due with linux marketing. This is plain my idea though.
JBoss will continue as a solution  in the market but it will most
likely face some competition from GlassFish or what not in give or
take two years. The reason I see WebSphere and Weblogic still have
some market share is their strong support team, which kick ass
anyways. On top of that many CEOs, and by many I do mean a high
number, do not know there is commercial support behind solutions like
JBoss.

> may be, just may, thats because of Maturity of JPA and hibernate
> hibernate has made great advances from version 2 to 3, after
adopting JPA
> standard,
> which was really merging the hibernate, toplink, kodo, castor, and other
> ORMs
>
> speaking of my self, currently I don't have any serious design
problem with
> Hibernate,

Hibernate is a mature product for sure, but from time  to time you get
stuck on various design or implementation flaws it has, which takes
80% of your time. There are still a lot of bugs in various places (the
famous criteria/sub criteria bug, problems with criteria and
components, ... ), the crap CGLIB library used in proxying is a pool
of bugs, and there are a lot of places for improvement which are left
out. Look in hibernate JIRA to see how many issues are open, and
remember these are only part of user issues which manage to make it to
the open issues list. Other issues normally get ignored or closed by
the ever so arrogant hibernate team. What redhat/jboss have done is
leave out a framework with 90% popularity, to work  on a framework with
hardly 5% usage in java world.

> but from the time you have introduced me Wickets,
> I can't keep thinking about how could I have Inheritance in web UI
> technologies I use.

I dont get what you mean here. Can you clarify a bit ?

I agree with your first point,
I am searching for a way to be able to inherite a JSP, JSPX or Facelets page from another page,
similar to the one we have in swing.