Re: System contracts

From:

=?ISO-8859-1?Q?Arne_Vajh=F8j?= <arne@vajhoej.dk>

Newsgroups:

comp.lang.java.programmer

Date:

Sat, 22 Jan 2011 11:00:09 -0500

Message-ID:

<4d3aff05$0$23757$14726298@news.sunsite.dk>

On 21-01-2011 23:40, gk wrote:

On Jan 21, 7:03 pm, Arne Vajh?j<a...@vajhoej.dk> wrote:

On 21-01-2011 04:06, gk wrote:

On Jan 21, 6:29 am, Arne Vajh?j<a...@vajhoej.dk> wrote:

On 20-01-2011 06:24, gk wrote:

On Jan 20, 3:35 pm, Arved Sandstrom<asandstrom3min...@eastlink.ca>
wrote:

On 11-01-20 12:29 AM, gk wrote:> JCA has a benefit over custom solution because System contracts

defined between application server and EIS resource adapter provides
connection pooling.

Could you please explain what kind of system contract we can think of
here ? Is it like what XML can be transferred OR what sort of
contracts we are after ? I would like to know more information at this
part.

The book or article that you pulled the first paragraph from should have
listed the JCA contracts, seeing as how it mentioned them; if not, toss
the thing in the trash.

JCA system contracts defined in version 1.0 of the JCA spec pertain to
connection management, transaction management, and security management.
"Contract" in this sense simply means a related set of requirements
between J2EE app server and EIS resource adapter.

Could you please provide one real example here. Is it like 30
concurrent connections , 10 minutes timeout etc ? Do you call these a
part of "System Contract" ? What sort of requirements generally takes
place ? I'm not familiar. I'm sure these are not business
requirements ..right ?

I have found System Contract information. I have found this
http://java.sun.com/j2ee/images/Connector.jpg

Could you please be specific at this part.

Those contracts are not specific.

There are some interfaces that must be implemented by
some classes and some expectations about who do what
when.

Not clear . Couple of doubts here.

(i)Are there any popular JCA products who implements by some classes ?
(ii)Does this kind of JCA product connects and bridges between
Application server and EIS ?

All outbound JCA connectors bridges between app server and EIS -
that is what it is intended for.
I think most JCA connectors are internal due to its
nature.

But standard products do exist.

Google found:

http://www.iwaysoftware.com/products/adapters/jca.html

>>
http://sourceforge.net/projects/sapbapijcaadapt/

Can not we use JCA Adapters for STANDALONE java applications to bridge
to EIS ?

Does java applications needs to be deployable in J2EE App server in
order to use JCA Adapters ?

You can use a JCA connector from a Java SE app. At least the
outbound part. I don't think that the inbound part is possible.

But this (called unmanaged in the spec) is not that interesting.
The connector just becomes a library that the client code calls.

And the system contracts between the app server and the
connector goes away.

Arne