Accessing Java Connector Architecture (JCA) from a Non-Managed environment

Question

Hi,

We have been using a JCA to interface with a low-level network resource from within WebSphere, however we have a requirement to be able to access the same network resource externally from Tomcat (i.e. not in a managed environment). The network communication and protocol layouts is very verbose, so we would rather not copy/paste several thousand lines of code (and then have to maintain them separately).

From reading the JCA spec, there is supposedly some support to execute the code in a non-managed environment (such as Tomcat). Unfortunately, I have no idea what the interfaces are supposed to do, or how to call them from outside a managed environment (the spec is pretty vague).

Are there any implementation examples out there that show how to modify a JCA to be usable in a non-managed environment?

Thanks!

Answer 1

We had similar case, where we developed a connector to access external WebDav storage, and wanted to use it also from a stand alone application (non-managed).

I do believe that the easiest way is to solve this at the design level, and organize your code in a way that the connector's core logic is JCA-agnostic and can be reused easily. Then you can wrap this with JCA-specific code that exposes the connector to the AS. It could probably even be packaged in two jar -- That's at least the solution we choose (but we packaged all in one .jar).

Otherwise, a JCA connector is the "glue" between the following three parties:

1. the Application Server
2. the EIS
3. the Application Component.

It should be possible to simulate the AS with a lightweight implementation of the necessary classes, and then use the JCA connector directly.

One main job of the AS with respect to a JCA connector is to manage the pooling of connections, and from what I remember, the corresponding interface that you should then implement is ConnectionManager.

The JCA connector receive a reference to a ConnectionManager, but the implementation is AS-specific. Writing a lightweight implementation that provides rudimentary pooling (or no pooling at all) sounds feasible.

I had written once a sequence diagram of the connection allocation mechanism. Maybe you will find it useful. Another interface is ResourceAdapter where you define the startup/shutdown, but that's easy to invoke manually.

(There is probably a bit more than that, and it of course depends on what your JCA connector uses. For instance, if it use Work and the WorkManager, then it becomes a lot more complicated to mock. Same remark if the connector is transactional. But it doesn't seem to be your case.)

Otherwise, I think that Spring has some support for JCA, it may be worth having a look how they did it.

From reading the JCA spec, there is supposedly some support to execute the code in a non-managed environment

Can you mention the specific part of the spec you are referring about?