This week's book giveaway is in the OCMJEA forum. We're giving away four copies of OCM Java EE 6 Enterprise Architect Exam Guide and have Paul Allen & Joseph Bambara on-line! See this thread for details.
the above examle shows how you can set isolation level through EBeans
in ejb3 it is not possible to set isolation level programatically if you are using connection pooling,to set refer your servers Docs
if you are not using connection pooling then you can set isolation levels programatically like this