Integration tier (Integration of Service activator & Adapter)

[Srinivasan Rengan]

Hi All,

DAO forms an elegant pattern when it comes to integration tier.

I was trying to bring in service activator into this tier, but faced with a small query.

Can we bring in both service activator and adapter into the integration tier [service activator (which could be a facade class, probably an MDB) using a adapter to send messages to external services]?

Thanks
Srini

[srivastava ashish]

Hi Rengan,

Few questions before i could help you .You want to use MDB as a service activator which is fine according to me but which kind of adapter you are talking about .Is it a JCA resource adapter??.Is your external system an EIS or Legacy??

What is your use case for implementation of DAO(just give me a hypothetical scenario)??

Ashish

[Srinivasan Rengan]

Hey Thanks for your reply..

I have an MDB. On receipt of the message it sends message to multiple external services. These services could be JMS based services or even mail servers.

Now I have adapters for all the above mentioned list of external services.

My query is that if we are using these adapters, can we show them into the integration tier of the component diagram? As a service locator my MDB would qualify. I have few DAOs which would also qualify. But these adapters...would they qualify as helper components?

[srivastava ashish]

Have you thought of putting them in Resource/Data Tier..I think its the best place for the kind of functionality you mentioned

[Srinivasan Rengan]

You mean the MDB or the adapters?

Also, if I have a requirement to show up a JMS Queue as part of my own system (Not external), in such a case should I show that up in class diagram? Also what happens in sequence digram?

Thanks in advance.

[srivastava ashish]

Adapters can be a part of Resource/Data tier (Refer : Mark Cade study guide -Second Addition Pg.18).

For Sequential Diagram you would like to show an asynchronous message flow (its representation is different from sync flow).i think you don't have to worry about JMS queue explicitly in sequence diagram.

I believe JMS queue is not represented in class diagram .It only deals with Classes,interfaces ,their relationship and collaboration.


Ashish

[Srinivasan Rengan]

Hey Srivastav!

Thanks for your replies...they were spot on!!

I have few more questions here:

This is my situation:

My component diagram follows the tier approach (Courtesy: Humphrey Sheil)

In BT (business tier) having one inventory related facade...Now this facade does two things for me...sync request and also async
request...In order to get from an internal inventory system it does sync request...for sending a another type of
request (secret LOL) to an external system sends a async request...

For the sync request I thought of having an DAO which makes more sense...so did that..but for async request i send a request to
the external queue...I thought I should use an adapter here...So in this case, i put the queue adapter in the integration
tier...Does this sound sensible?

Also, another question which I get here is...how do I show the interaction between the external queue and the adapter...I mean..how to depict that in the component diagram? Can I just use a <<uses>> here? (Humphrey Sheil does that...but he just uses DAO classes in the integration tier...)

Thanks.
Srini