Berkeley DB Java Edition (JE) has had J2EEConnector Architecture (JCA) support for quite a while, but until now the only supported J2EE servers that we supported were JBoss and Sun Java System Application Server. As of release 3.2.28 JE will support JCA under Oracle Containers for Java (OC4J), version 10.1.3.2 or later. This is the logical "next app server" for us to run on given that JE is now an Oracle product. Frankly, it is just one of those things that didn't make it to the top of the queue until an internal user asked us for support. 3.2.28 will be out in a while, but if you need support for OC4J sooner, please drop me an email and I'll see what I can do for you.
Thanks to Tom Beerbower for helping to get this working.