Panindrakumar Balellugari

There is a 1 - year time limit for submitting the assignment after the download. I remember reading it in Sun web please verify.

Thanks,
Panindra

It mainly depends on why you�re using SLSB to implement this task. I assume that you want to use container provided abilities of transaction, security, threading etc functionality instead of coding them on your own.

As you have said all these tasks are sub tasks that is implemented by SLSB since you got all the features that you need as i said above. I would recommend using helper classes to implement the sub tasks.

One more thing to keep in mind before you start creating helper classes is that, if you think that these sub tasks can be invoked directly without the need of main task then you have to think this through before.

Thanks,
Panindra

It depends on the type of application that your trying to design. Its not mandatory that Account == Customer.

Thanks,
Panindra

JCA is the best approach because you can handle transactions if needed, which is never available in screen scrapping.

Screen scrapping as you've said must be the last option in J2ee development.

Thanks,
Panindra

On top of it there is no need for specifying protocol information in a SEQ diagram.

Thanks,
Panindra

You can depict it using a self IF condition on object where it is executing. But this level of detail is not recommended in SEQ diagrams, because it will confuse the developers more.

Thanks,
Panindra

There is no need to mention Home or Remote interfaces in any of the class diagrams. Reason is that its understood that EJB cannot exist without home / remote interface (with exception to MDB) and home / remote do not add any value to the class diagram.

As its been said before you can just use <<SLSB>> or <<SFSB>> or <<CMP>>. Ultimate goal is somebody other than you must be able to understand the class diagram without trouble.

Thanks,
Panindra

Controller should be a servlet. Key to note is that if SFSB is a controller then there will be a controller created for each user. But in reality a job of a controller is to control flow of the request and responses, which is generic to the entire application. Hence servlet as the Controller is the right choice.

I hope this helps.

Thanks,
Panindra

Your right again, if you look at your PD all of them are interfaces. So you can leave this layer untouched but the problem is that all entity beans in the DM implement interfaces from PD.

This means that interfaces in PD should atleast consider the basic skeleton , about the way you want to implement the persistence. I mean your interface should be inline with your thought process about persistence.

One more way to address your thought to "keep any technology aspect out of the BDOM" is to design the entity beans such that they use DAO. Which would really worry about the technology aspect of persistence and do away with the interfaces in the PD and instead move the entity beans up to the level of BDOM and move the DAO (classes) to the DM. If this is your choice then you have to do away with CMP beans, but if you want to use CMP then container is really going to worry about the technology aspect of persistance .

I hope this help's. Let me know your thoughts.

- Panindra

We need not develop any code, we just need to design/architect the application.

J2EE API to use:
APIs relevant to the Assignment

The assignment requires that you have an in-depth understanding of the Java programming language and J2EE APIs. You can choose to use any released version of the J2EE APIs.

taken from http://www.sun.com/training/catalog/courses/CX-310-300A.xml

Hope this helps.

- Panindra

This is an exhaustive post . Let me try to answer the questions.

1. Association between the product and order: If you check the class diagram again you can see that Order-->OrderItem--->Product relationship.

2. Changes to the BDOM: Class diagram didnot change the BDOM. It just elaborated BDOM adding more components and created more detailed view (class) using BDOM as base.

Now let me try and answer other questions.

A. How to implement the busniness logic with above technologies? How would these look in our class diagram?
Answer to first part of the Question: First we need to move the detailes provided BDOM in to different TIER (Client, Presentation, Business & EIS / DB)
Answer to second part of the Question: Now for each tier we have to start designing.
Client Tier - Create user experiance
Presentation Tier - Create class diagrams
Business logic - Create class diagrams
EIS / DB Tier - Create ER diagram based on the BDOM.
Other than class diagrams we might want to use Activity, Sequence, Collaboration diagrams. These diagrams will be very useful during the implementation. These are optional and can be used based on the need.

B. What about Persistence? How would this look like in our class diagram?
There are two aspects to persistence:
1. Class diagrams: EJB's represent datastore in terms of java object, it can also be DAO or may be POJO's that is used to access data.
2. ER diagrams: This will be useful to design the database and will be very useful to care to create DB.

I hope this is helpful and i expect other to contribute.

- Panindra

Your approach is correct, for confirmation you can try any shopping site. Steps included are.

1. Browse product / view itineray
2. Choose product / itineray
3. Add product / itineray to the cart.
4. Repeate steps 1 to 3 for each product
5. Review the cart
6. Check out / pay
7. Persist data once payment is through

Right way to implement this would be to persist data to DB only after checkout. That means payment has to be accepted and then only we can persist. Best way to do this would be to use SFSB(Stateful session bean) to store the shopping cart values and use SLSB(Sateless session bean) for payment service. Entity bean (CMP if data is straight forward) for persistence.

Couple of points to note in this approach:
-------------------------------------------
A. If because of some reason user is diconnected before he/she checks out all the data in the shopping cart is lost [That is shopping cart SFSB should be destroyed / timed out]

B. If user payment validation fails or it takes more time than the instance response we expect then we should persist the data in some temp DB till we get response.

I hope this helps.

- Panindra

Possible candidates for this are A, B & C. Since the data will be used only for browsing and no e-commerce. BMP / CMP is not needed.

Out of A, B & C.
A - We need as controllers
B - For displaying HTML, but this option also has java classes hence we might want to be careful, i would say we need not choose this.
C - We need this option for retriving data from database.

So the final answers could be only A & C, if java classes were not part of B then we might want to include that too. Hope this answers your question.

- Panindra

your_server_*** is configured in your jboss3**.server file. This file could be found under ECLIPSE_INSTALL_DIR\plugins\com.objectlearn.jdt.j2ee_3.0.1\servers folder. This is file which defines how you connect and manipulate your JBOss server

Change entries of /your_server_root/appservers/ to you eclipse installation directory.