On 5/19/10 4:28 PM, David Jencks wrote: > > On May 19, 2010, at 1:16 PM, Donald Woods wrote: > >> Good summary Lin. >> >> In the OpenJPA community, we've been telling users for awhile now not to >> use the runtime enhancement, as it has known deficiencies, and should >> only be used for quick prototyping and never in production. > > What are these deficiencies? I thought you got the same bytecode whether you > ran the enhancer using maven or as the classes are loaded using a class > transformer. I know the subclassing approach doesn't work well but that is > not being discussed here AFAIK. >
Javaagent - yes, it should be the same. Subclassing - no, that is what we tell people not to use. BTW - Geronimo is the only App Server that we know of that uses the -javaagent method for enhancing.... -Donald > Is this stuff documented clearly somewhere in the openjpa docs? I've never > found a comprehensible explanation when I've looked in the past. > > thanks > david jencks > >> >> If we need to continue supporting this in Geronimo (for the developer >> scenarios), then I'd go with #3 for now. >> >> >> -Donald >> >> >> On 5/19/10 11:19 AM, Lin Sun wrote: >>> Seems No. 3 is the right approach, given that there is no overhead on >>> the user side and it gives the ability to add the imports at the last >>> minute, before the PU is resolved. >>> >>> No. 2 gives some extra work on the user side which can make the PU not >>> portable. >>> >>> Np. 4 has to be done when PU is installed, and it is possible the >>> provider is not even there yet. >>> >>> No. 5 can be confusing to the user as a fragment is attached to their PU. >>> >>> Lin >>> >>> On Tue, May 18, 2010 at 10:41 PM, Jarek Gawor <jga...@gmail.com> wrote: >>>> Hi all, >>>> >>>> I was looking into getting the runtime JPA entity enhancement for OSGi >>>> applications working in Geronimo. With some modifications to the Aries >>>> JPA code and some to Geronimo I was able to get runtime enhancement >>>> working (using the java agent approach) but with one major issue: The >>>> bundle that contains the persistence unit must be able to load some >>>> persistence provider specific (in our case openjpa) classes. That's >>>> because during the bytecode weaving, openjpa adds some openjpa >>>> specific interfaces to the entity classes. So how should we deal with >>>> this issue in Geronimo? >>>> >>>> 1) We could do nothing and just say we don't support runtime enhancement. >>>> >>>> 2) We could support runtime enhancement and require that bundles with >>>> PU have DynamicImport-Package: * header. >>>> >>>> 3) Use framework "classloader hooks" to dynamically add imports for >>>> the persistence provider specific packages to the bundles with PU . >>>> That of course, would rely on framework specific extensions. I know >>>> Equinox has such hooks and I think recently something similar was >>>> added to Felix. >>>> >>>> 4) Provide some url handler, e.g. "jpa" which would enhance the entity >>>> classes and add right imports during the install. Something similar to >>>> the "webbundle" url handler for web application archives. Of course, >>>> we would have to make sure the bundles with PU get installed via the >>>> url handler. >>>> >>>> 5) Have some kind of an extender that would generate a fragment bundle >>>> (with right persistence provider imports) and attach it to the bundle >>>> with PU. Or something similar that would require manifest modification >>>> or generation of additional bundle. >>>> >>>> Thoughts? >>>> >>>> Jarek >>>> >>> > >
