As explained in the above URL, with JBoss, you can set the JDBC transaction isolation level in the xml file that contains the JDBC connection information.
I've been doing some googling, but I'm not clear on how this can be done with WebLogic. Is there some kind of external file where you can set the JDBC transaction isolation level as with JBoss, or is this some kind of change that can only be made in the application code or in some file contained within the application archive file (ear, war, etc.)?
You can set the isolation in the deployment override weblogic-ejb-jar.xml