Migration from oc4j to tomEE

Question

We are planning to migrate our Java WebApplications from OC4J to TomEE. I need to provide an LOE for this migration What are the key points regarding the migration? Is there any documentation or books that I can refer to ??

Answer 1

First, congratulations. The lightweight nature of TomEE offers some incredible advantages. Being open source, you're also able to fix bugs on your own, without relying on your vendors slow development cycle. Plus, because it's basically Tomcat, you're tapping into a massive knowledge base and world of experience around the product.

The best advice for a migration like this is to make sure your apps use vanilla Java EE and nothing else. If your code compiles against javaee-api-6.0.jar without any OC4J libraries, chances are you're 90% the way there.

The rest of the problems usually deal with minor points on configuration and injection.

If you do strange things with EJB mappings:

@EJB(name = "NoteTakerServiceBean") private NoteTakerService umaNoteTakerService; @EJB(name = "GLINoteTakerServiceBean") private NoteTakerService gliNoteTakerService;

These "named" injections are not portable.

Configuration properties on MDBs:

@MessageDriven(activationConfig = {
    @ActivationConfigProperty(propertyName = "destination",
            propertyValue = "com.mycompany.databunker.salesforce.model.SalesForceAgent"),
    @ActivationConfigProperty(propertyName = "maxSessions", propertyValue = "1") },
        mappedName = "com.mycompany.databunker.salesforce.model.SalesForceAgent")
@TransactionAttribute(TransactionAttributeType.REQUIRED)
public class SalesForceAgentMessageListener implements MessageListener {
....
}

The activationConfig properties are container specific.

To assist you with the migration, TomEE has the best documentation out there. See these two pages to see how to see where I got the configuration details for the above beans.

http://tomee.apache.org/examples-trunk/index.html

http://tomee.apache.org/documentation.html

Finally, another great resource is the Apache TomEE users list. There are many helpful people on there. Good luck, be sure to post there or back on SO if you have further questions!