Hi Adam, You are right in your thinking not to use the "fall back" enhancement processing for production use. It was meant as an easy "out of the box" experience for simple apps. It was not meant for production use. All of this has been documented in our forums and JIRAs (which you have already found).
We are doing more investigation into the Java 6 class redefinition support. This doesn't seem to be 100% complete either, at least for some scenarios. So, the best bet (and most proven) is to stick with standard PCEnhancement. This can be done in several ways -- statically during build, or dynamically via the -javaagent approach or tied into the classloader of a suitable EJB3 container. In the WebSphere environment, the classloader enhancement process is tied into both the EJB and Web Containers (same Java EE runtime implementation). But, it doesn't sound like this linkage is provided by Tomcat. I have no direct experience with Tomcat -- just reading your note below. So, it sounds like your best approach is to do the enhancement during the build process. If you are experiencing un-enhanced entities at runtime, then either your build-time enhancement is not working, or your packaged application isn't picking up the enhanced classes, or you accidentally have non-enhanced entities also available via your Tomcat environment. Because we don't want our WebSphere customers to accidentally use the "fall back" enhancement, we actually turn this off for OpenJPA within WebSphere. You can do this with this property in your persistence.xml file: openjpa.RuntimeUnenhancedClasses = warn By default, this is set to "supported". Another value is "unsupported", which just detects the problem a little earlier. By using "warn", you still won't fall into the "fall back" enhancement and you will get some more helpful messages concerning the entities that have not been enhanced. I don't have a specific, complete answer to your situation. But, maybe if you can experiment a bit with the above information and provide some more details, we can help get your environment working to your expectations. Good luck! Thanks, Kevin On Fri, Feb 6, 2009 at 9:05 AM, Adam Hardy <[email protected]>wrote: > I need to enhance the entities in my current project because otherwise with > 'fall-back' enhancement, the core functionality of the application cannot be > run, due to StackOverflowErrors (because of the large number of unenhanced > entities that OpenJPA has to deal with, according to JIRA and the mailing > list archives). > > I'm running Java 1.6.0_12 so I think I'm right in saying that the runtime > enhancement used by OpenJPA on the unenhanced entities will be Java 6 class > retransformation - but it's causing the issue above. > > I have tried specifying the javaagent as a JVM option, but I have some > problems with this in the web server. I'm using tomcat and it looks like I > have to put my complete webapp into tomcat shared directory so that the > enhancement process has the classes available at boot. > > My entity beans have a fair amount of encapsulated business logic so there > are a fair number of external utility classes and jar dependencies. > > Is there a way to configure the javaagent on a per-website basis for > tomcat? > > Secondly I have configured the openjpa-maven-plugin so that it launches the > PCEnhancer during my maven build, but the x*?!"@ app doesn't run with the > build-time enhanced classes. > > It just hangs while loading the webapp, when Spring tries to load the > managers (the transaction-wrapped business tier). That's both during > integration testing with JUnit and when deployed in tomcat. > > I think that sums up my current situation. Can anyone suggest a way > forward? > > regards > Adam >
