Gaurav Totla

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since Aug 23, 2004
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Recent posts by Gaurav Totla

Aditi, the only issue issue with 1.6 is there are not many mock tests or questions available for 1.6.But for 1.5 you will now get many information.

Being said that I totally agree that it is best to give the latest available certification. If you have just started preparing and it will take some time before you give the exam then I believe you will get much more info on 1.6 but if you are planning to give 1.6 very soon then just have a check on the available resources.

You can also talk to the people in the forum (check out the results forum)who got good results in 1.6

Gaurav
Hi Mihai

Couple of things-
1. EJB3 in action examples uses the Apache derby database by default.
2. Before running any example you need to start the database by Start > Programs > Sun Microsystems
> Application Server PE 9 > Start Java DB
3. It will start the database server on a new command prompt and you can press enter to run it in background.
4.Once you have started the server (Glassfish) and the database, you need to run the build file which is present at the top level folder of the source code i.e c:\ejb_3_in_action\code_examples.This will prepare data sources and JMS resources necessary for the database.
5. After doing this you can go to each chapter and run the specific build file.i.e cd chapter1 and ant.

I apologize if you have already followed these steps before posting the error.

Gaurav
Have a look at this link for some code example
Hi Joby,

I found a nice summary in the book EJB 3 in Action

A session bean alternative: Spring
Clearly, EJB 3 session beans are not your only option in developing your application�s
business tier. POJOs managed by lightweight containers such as Spring could
also be used to build the business logic tier. Before jumping on either the EJB 3
session bean or Spring bandwagon, think about what your needs are.
If your application needs robust support for accessing remote components or the
ability to seamlessly expose your business logic as web services, EJB 3 is the clear
choice. Spring also lacks good equivalents of instance pooling, automated session
state maintenance, and passivation/activation. Because of heavy use of annotations,
you can pretty much avoid �XML Hell� using EJB 3; the same cannot be said of Spring.
Moreover, because it is an integral part of the Java EE standard, the EJB container
is natively integrated with components such as JSF, JSP, servlets, the JTA transaction
manager, JMS providers, and Java Authentication and Authorization Service (JAAS)
security providers of your application server. With Spring, you have to worry whether
your application server fully supports the framework with these native components
and other high-performance features like clustering, load balancing, and failover.
If you aren�t worried about such things, then Spring is not a bad choice at all and
even offers a few strengths of its own. The framework provides numerous simple,
elegant utilities for performing many common tasks such as the JdbcTemplate
and JmsTemplate. If you plan to use dependency injection with regular Java
classes, Spring is great since DI only works for container components in EJB 3.
Also, Spring AOP or AspectJ is a much more feature-rich (albeit slightly more complex)
choice than EJB 3 interceptors.
Nevertheless, if portability, standardization, and vendor support are important to
you, EJB 3 may be the way to go. EJB 3 is a mature product that is the organic
(though imperfect) result of the incremental effort, pooled resources, shared ownership,
and measured consensus of numerous groups of people. This includes the
grassroots Java Community Process (JCP); some of the world�s most revered commercial
technology powerhouses like IBM, Sun, Oracle, and BEA; and spirited opensource
organizations like Apache and JBoss.



I believe in the coming time both spring and EJB will complement each other as there are already efforts put to integrate both these technologies.
Hi,

As par my understading EJB timer service is only applicable to Stateless session beans and MDB's. If you try to invoke getTimerService() for Stateful session bean container will throw an IllegalStateException.

As par specs
"ejb-3_0-fr-spec-ejbcore
Timers cannot be created for stateful session beans[94] or EJB 3.0 entities."
[94] This functionality may be added in a future release of this specification."
Hi

I dont think there is any Head First for EJB3. I read somewhere in this forum only that the new version will come by next year only.