Granny's Programming Pearls
"inside of every large program is a small program struggling to get out"
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Michael Antonov

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since Nov 16, 2009
Russia
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Recent posts by Michael Antonov

This particular book is going to be somewhat like many in my team (well, and I myself ) are need in - as database is a heart of enterprise system, some small issues in UI can usually be overcomed or fixed easily, and database related problems are harder to fix and often can cause performance, scalability, and pretty much convenience of the data operational API to be really bad.

Waiting to read out your book and compare that with what i have in my mind now, and also share that with some guys in the team I'm working in.

Welcome to JavaRanch!
Just for example, in company iam working where it is used widely. JBoss AS is used also.

thuy nguyen wrote:I cut and paste this paragraph from the specification:

The message-driven bean class may have superclasses and/or superinterfaces. If the message-driven
bean has superclasses, the methods of the message listener interface, lifecycle callback interceptor
methods, the timeout method, the ejbCreate method, and the methods of the MessageDriven-
Bean interface may be defined in the message-driven bean class or in any of its superclasses.
A message-
driven bean class must not have a superclass that is itself a message-driven bean class

Since a MDB can not subclass another MDB, it can only subclass a POJO. It is strange that a POJO can have
"the methods of the message listener interface, lifecycle callback interceptor methods, the timeout method, the ejbCreate method, and the methods of the MessageDriven-Bean interface"


That is not strange really. You can create a POJO superclass, which has onMessage method, and which is implementing the appropriate interface, say MessageListener.
That you create just a empty class which subclasses your superclass, has @MessageDriven annotation, and no onMessage method. This is valid. onMessage method for MDB will be picked up from superclass.

Prasad Kumbhare wrote:If I understand your question correctly about Timer, you want to know how Timer works. Right ? I didn't get your question correctly I apologize.

Timer can be two types, programmatic and automatic.
For Programmatic Timer, you inject TimerService in your Bean and create Timer programmatically using one of the 4 createTimer methods of TimerService.

When Bean instantiates and come to the point where it can create timer, it creates Timer instance and Timer executes timeout callback method as specified while creating timer.

For Automatic Timer, we can use @Scheduler. You can specify when you want to run a particular task in schedule. Timer gets created automatically.
Timer doesn't die with Bean. Once it gets created and bean dies still Timer can execute in the server.

Below URL has some more good information on timer.

Timers in EJB3


Thanks.


Well,that is really interesting and useful what you did say about Schedulers, but that is part of EJB 3.1 and hence out of SCBCD 5.0 scope, do you agree?
I meant topic starter probably asked about times in 3.0 only.
Well, thats only up to you.
But if you already have significant expirience in the EJB 2.1 - why not you take some time and get certified at EJB 3.0?
Benefits are:

- See what are the new features, and go over all features in structured way during cert. preparation
- New powerful technology in your tech. stack
- better vision of the differences and +/- of the mainstream frameworks.

I decided, that it deserved several weeks to prepare/pass. What about you?
In general I do agree, there are quite a log of question related to annotations.

I myself can recall off-hand only 2 areas where the XML elements knowledge is being tested.
1st is resource injection/referencing. There are both xml and annotations need to be known good.
2nd is security stuff. Namely roles, role-refs, role-links etc.
Thank you, thank everyone
For now, will temporarily hold the certification on, and get deep into patters/architectural stuff.
And also into mainstream technologies like Spring and Hibrenate.
Well, and some web 2.0 things. like Flex, ExtJS etc..
8 years ago
Yes, and i forgot a bit..If someone interesting in my expirience here..

First, check the things which you can suspect of incorrectness (in mocks, in articles etc) against the EJB official spec. Which is referred commonly as "EJB Core".
Next, yes, work on that at least 4-5 days in week, each time not less then 3-4 hours. For me it took like 3 weeks or so.
Last, just believe that its quite possible to get high score

8 years ago
And here are the steps I did to get here...
(sorry for possible errors, iam not english native.. )

1) I had about a half of year of working expirience with EJB 3.0. Read Sun JEE Tutorial initially.
2) Than, at the beginning of certification preparation, I missed the books like EJB in action and such. Instead of I read M Zalkin book (must admit - wonderful book! And perfectly aligned to the real exam scope). Read it once, and spend some time to partially read one more time (immideately after that) to keep the difficult things in memory.
3) Last morning, in the day of examination, I read the SCBCD last minute notes (http://faq.javaranch.com/content/bcd5_notes.txt) and it was quite helpful.

Yes, and also I passed several trial exams of Whizlabs and uCertify.
8 years ago
Thank you all, promising to keep up
8 years ago
Hi everyone,
I passed SCJP in July 2008 with 80% scope...and now am looking for SCBCD!
What does someone think in means of comparizon? Is scbcd harder quite a lot or no?
8 years ago