RMI-IIOP and JNDI

[Iyengar Srividya76]

Hi...
Can anyone throw some light on RMI-IIOP and JNDI...
Thanx in advance...
Vidya

[LAXMI VEMARAJU]

Hi vidya,
I can explain you in brief...
An EJB client uses a bean's remote interface to access business logic that the beans supports. The client calls methods defined on the remote interface through RMI-IIOP protocol.
Before calling methods on a remore interface, a client must locate the target bean and get a reference to an object that implements the remote interface. A client uses the JNDI to locate(lookup) a bean and the bean's home interface to get a reference to the remote interface.
laxmi

[Ram Dhan Yadav K]

RMI-IIOP is a protocol. JNDI is a directory service.
We user RMI-IIOP to communicate We register EJB/Enterprise
with server. resources in JNDI.
In total we use RMI-IIOP to talk to the Enterprise resources which are registered in the JNDI system.
This is just a small part of the big picture.
Does that make sense. Any more input would be appreciated.
Thanks,
Ramdhan YK

[Iyengar Srividya76]

Hi...
Thanx for the info.... can u tell me what's the difference between the RMI and the RMI-IIOP protocol...
Vidya

[Iyengar Srividya76]

Hi...
Can anyone pls explain the following statements picked up from the Orielly book page 44....
The network traffic and connections used by a client that uses only entity beans is much higher than the client that uses session beans...
Session beans limits the number of stubs used on the client, which saves the client memory and processing cycles.... But without the use of session beans, a client might be expected to manage hundreds or even thousands of remote references at one time...
Thanx ..
Vidya

[karthik gopalan]

RMI is a method for invoking remote objects. IIOP is a protocol which lays over TCP/IP. RMI-IIOP which in turn means RMI over IIOP is for invoking remote objects using the IIOP protocol
cheers
Karthik

[Iyengar Srividya76]

Thanx Karthik...
Vidya

[herve attia]

Originally posted by Iyengar Srividya76:

Hi...
Can anyone throw some light on RMI-IIOP and JNDI...
Thanx in advance...
Vidya

RMI IIOP http://www.npac.syr.edu/projects/cps714fall97/hw4/msen/#rmi-iiop
herve

[Iyengar Srividya76]

Hi Herve....
Thanx for the other info u gave... really helpful.... but in the site u gave previouly.. there are some sample questions also... and it shows long answers too.... does this part I exam have long answers.....
Also can u tell what type of questions will be asked for EJB and design patterns.... Did u have any experience in Design Patterns.... I am finding it difficult.... which book did u refer....
Thanx again...
Vidya

[herve attia]

Originally posted by Iyengar Srividya76:

Hi Herve....
Thanx for the other info u gave... really helpful.... but in the site u gave previouly.. there are some sample questions also... and it shows long answers too.... does this part I exam have long answers.....
Also can u tell what type of questions will be asked for EJB and design patterns.... Did u have any experience in Design Patterns.... I am finding it difficult.... which book did u refer....
Thanx again...
Vidya

The SCEA first part is to test your knowledge of the different concept involved in a J2EE architecture.
You need to understand the EJB lifecycle, which design pattern has been used to implement some j2EE concept...
I used to implement some design pattern ( without knowing it was)
- better to implement J2EE Service locator pattern as a singleton ( see singleton pattern )
- Data access object uses Abstract factory pattern.
- J2EE Value List handler pattern uses Iterator pattern...
Read Design Pattern GOF, pattern in java, Core J2EE pattern.
For general architecture questions, I always refer to "Building Java Enterprise Systems with J2EE" (paul perrone)
Don't forget SCEA exam is also general architecture questions : UML, protocols, network, security.....All that a architect has to know when he builds the customer's requirement system.
Herve Attia

[Mangesh Apte]

The network traffic and connections used by a client that uses only entity beans is much higher than the client that uses session beans...
Session beans limits the number of stubs used on the client, which saves the client memory and processing cycles.... But without the use of session beans, a client might be expected to manage hundreds or even thousands of remote references at one time...

Vidya,
If the client uses entity beans directly, the workflow possibly resides in client. So for any data related opeation (CRUD), there is a remote call, which increases network traffic. No need to mention client needs to manages stubs for all entity beans...more memory.
If session bean is used to manage workflow, any data related opeation is a local call (considering entity beans used by session beans reside in same container as session beans). Client will make one/few remote calls on session bean to perform operation, so reduced n/w traffic. Also, client will need to maintain stub for session bean only...less memory.
I think there is one diagram in the book which shows this.
Hope this helps.
Mangesh
[This message has been edited by Mangesh Apte (edited October 01, 2001).]