Dumitru Postoronca

Ranch Hand
+ Follow
since May 06, 2008
Merit badge: grant badges
Cows and Likes
Total received
In last 30 days
Total given
Total received
Received in last 30 days
Total given
Given in last 30 days
Forums and Threads
Scavenger Hunt
expand Ranch Hand Scavenger Hunt
expand Greenhorn Scavenger Hunt

Recent posts by Dumitru Postoronca

M. A. Riveros T. wrote:

Sure it does.

Sorry, but I disagree. What I expect from a company as large and prestigious as Oracle is a minimum of consistency: overall minimum PASS score should be equal to the sum of the section's minimum PASS scores...

Oracle also expects from us to understand, that not putting a minimum requirement on some sections gives us some flexibility. If one of your diagrams is very good and the other - no so much, as long as the sum gives you a passing score -- you'll pass. There are some minimum scores set, per diagram, because it would be stupid to pass somebody that doesn't have a proper class diagram, that's why there is a minimum score for that specific diagram.

Also, the approximate 71% passing score seems a reasonable requirement, considering that, as you said, Oracle -- this prestigious company -- will be is calling you an Architect.

jianming chen wrote:

1. Do you have such a requirement?

We do have requirement like this. Sometimes we want to create some sort of quick tool outside of the Web Application which requires access to the database. Or sometimes Swing application.

My advice to you is to stick with the requirements in the assignment.

jianming chen wrote:
Yes, but DAO is an integration tier pattern. Based on the DAO pattern definition on Core J2EE Pattern, Use a Data Access Object (DAO) to abstract and encapsulate all access to the data source. The DAO manages the connection with the data source to obtain and store data.

And in JEE applications, the container manages the connection. Don't take the definition in such a literal way. Also, just because it's called integration tier, it doesn't mean it can't live in the same environment as the business tier (same ear, same technology - SLSBs).

jianming chen wrote:

Jaime Bravo wrote:
2. On the other side, SLSB is an artifact and not the service tier, itself. So without problems, an SLSB could be in integration tier.

I think the idea of injecting EntityManager into SB is kind of mixing business tier and integration tier. The boundary of each tier is not clear any more. The major benefits of EJB container are security, transaction management. So it's best for business tier. DAO layer should be able to site outside of EJB container. Probably you want to re-use DAO component in other project deployed outside of EJB container.

1. Do you have such a requirement?
2. Reuse can also be about reuse within the same application, it doesn't automatically mean that it has to be across projects. Your design makes it (slightly) harder to reuse within the same application.

jianming chen wrote:
DAO pattern should provide unified interface for any kind of resources. It doesn't make much sense to wrap any other resource accessing code inside SLSB. Such as LDAP access, Web service client etc.

True, but DB access is transactional, as opposed to LDAP. Also, one could wrap LDAP acess in a SLSB because you get thread safety with a simple annotation.

jianming chen wrote:

Jaime Bravo wrote:
But actually look up a dependency from inside the DAO class is not a good practice, because you're creating a dependency with the lookup mechanism and details about the same one. And this fact adds another responsability to the DAO class, that is: find its dependencies. So the class becomes less cohesive. For example if you change the JNDI name for the dependendy then....you know. So Dependency Injection pattern is the winner against the Service Locator pattern.

Before EJB container can specify other classed inside DI context, I'd rather use other DI provider to manage dependencies in DAO layer.

You are adding one more dependency to your project, instead of reusing the existing dependecy on the EJB container.

To conclude, my opinion is that it's a bad idea.
Here is the URL to oracle's web site with the new information.

Deadline extended to September 30, 2011.
In order to ensure that you have at least one week to resubmit if you fail, you should submit your assignment and complete your essay by August 27, 2011.

Jeanne, I suggest you make this a sticky post as it's important for all test takers.

Krzysztof Koziol wrote:In my design I put Adapter between system and SLSB. In the Component Diagram it will be placed in the integration tier.

I believe you should think of it as a Proxy instead of Adapter. Proxy hides remoteness (your use-case) as opposed to Adapter that allows old code to be used with new classes (adapts one interface to another).

Jeanne Boyarsky wrote:In the sequence diagrams, I showed the session bean calling the entity manager. I named that class entity manager since it is a built in class.

Jeanne, are you saying that you didn't use the DAO pattern for DB access in your application?
I believe the 'deprecation' of DAOs for database access has it's upsides and downsides. Is there a community consensus regarding this practice? (I was under the impression that it's still debated )
I have created some POJOs for the external systems I access, to map the received data to those classes. I believe it's important, as I have to pass them to the view layer for rendering.
Hi all,

This question is related to JSP & Controller in class/sequence diagram question.

I'm trying to figure out how to display image loading in the sequence diagram. I have to do this as in my assignment, important business logic is being executed for this step.

(1) The only way I see that this can be done is that showing requests from the browser; having the browser as an actor in the sequence diagram. The browser makes a HTTP GET request for the JSP, and then makes an additional GET request for the image.
This would be a deviation from Cade's book where JSPs are shown to call the Controller (without showing browser involvement). Although I have no problem deviating from the examples, I want to be sure I am doing the right thing.

(2) Other idea would be to show something like this: menu.jsp calling Controller, Controller calls/renders viewItem.jsp, viewItem.jsp calls Controller.getImage(), getImage() returns the JPEG file.

Any thoughts on these options?

1) In Cade's book, class diagram, the JSP files <<use>> the Controller class. I find this odd, as what actually happens is that the browser will issue a GET/POST request that will be mapped to a Controller that will execute the business logic and then dispatch to a JSP to render the HTML in response. I believe that the arrows should be in the opposite direction -- the Controller using the JSP files.

A similar issue is in the sequence diagram, where
(2) there is no actor such as the user/browser and
(3) the JSP is calling the Controller. As per my observation above, the browser request is getting mapped to a Controller. It's the browser invoking the Controller, not the JSP. The only way a JSP would be calling some business logic (during it's "render" phase) would be if the JSP uses custom tags, but this looks like the Dispatcher-to-View pattern, which is not intended for heavy-business-logic pages.

Anyone care to comment on these?

Thanks a lot.

I got the TeamDoctor assignment. And it also mentiones beta in the document. Passing score (tentatively set) is 114 of 160.

I wouldn't ever give my card information via email (which is unsecure). If you entered the details via a https connection then I'd tell them to get the data on their end.
(disclaimer: i never bought anything from epractice, but still -- i'd never give out card information via email)

Now that Java exams are done at Pearson Vue centers, what is the procedure for getting a voucher?

Do I buy it from Oracle (link) or from Pearson ?

Please provide a link, if you have it.

Have you tried a basic google search or a search on this forum before asking this question?

1. ScbcdLinks
2. SCBCD-Highly-recommended-books
I have created a new class & new client and this time I get the expected EJBException.
No idea what happened before.

I am calling an EJB that throws a RuntimeException which gets re-thrown exactly as is to the client.

The code outputs 'Exception in thread "main" java.lang.RuntimeException at ses.MyOtherSes.methodThrowsSystemEx(MyOtherSes.java:23)'.
I'm using jboss 5.1GA.

I don't have an ejb-jar.xml file and i haven't specified RuntimeException to be an application exception. I do NOT understand why it throws it as is instead of throwing an EJBException.

Thank you.