I was able to run the JCA example by Scott Stark provided in teh Jboss book.
The following output was produced (as expected) : ---------- Created Echo Echo.echo('Hello') = Hello ----------
So, if i understand correctly, this means that I was able to retrieve a managed (pooling and access control) File System connection from my JCA adapter.
What would be the most logical place to put the code that actually performs the IO on my rootDirPath? I would think this code goes into FSDirContext. I am thinking of utilizing Sun's com.sun.jndi.fscontext.RefFSContextFactory to perform the IO using JNDI API.