EJB and JDO

[thomasp]

Hi everybody,

I finished an article about how to use JDO in BMP Entity Beans. Example works with jBoss 2.4.4. Here is the link:

http://www.intellibo.com/ibo/international/ejbjdo.pdf

Beside that, my point of view on how to integrate EJB's and JDO is given.

Please let me know any comments and suggestions, your input is welcome.

Kind regards,

Thomas

[davidjencks]

Nice article, thanks.

I would think that the classloading problems you mentioned could also be solved by putting the jdo vendor implementation classes into the ear with the enhanced classes. Did you try this? In jboss 3 all such problems should be gone.

Does your jdo implementation implement the (extremely confused IMNSHO) jdo spec "requirements" about jca compliance/support? Do you have any opinions about these requirements?

[thomasp]

Hello David,

thank you for your answer - and for the "nice article" ;).

> I would think that the classloading problems you mentioned could also
> be solved by putting the jdo vendor implementation classes into the ear
> with the enhanced classes. Did you try this? In jboss 3 all such
> problems should be gone.

I did not try it, but there is no reason why it should not work. We need to find the config file as a resource (and not even that, if you hard code) and the pc classes to work with. But our libraries are quite huge, so I do not think it's a good way to pack them all into the JAR.

I'm looking forward to new releases of jBoss 3, as the product itself is quite good and stable, there are just some dark "corners" where things are a little bit suspicious. But I know how hard it is to advance a product to a new version and still provide fixes for the current version.

> Does your jdo implementation implement the (extremely confused IMNSHO) jdo
> spec "requirements" about jca compliance/support? Do you have any opinions
> about these requirements?

We support as resources pure JDBC connection, DataSources, XA DataSources and JCA ManagedConnection Factories. Other resources are not possible currently, but in older versions of the JDO spec you can find plugable service providers. These can also use different resources, as I understood. But you can't use this in the version 2.5 of our product.

I did not try to build a .rar-archive, this would ommit the PersistenceManagerFactory instantiation inside the bean.

But this is what we wanted to do with the article: have a first working example, a basis for a discussion. The speed of advancement in JDO is slower than we expected.
We talked with our customers what they need for app server integration, now we try to communicate with the community and find out what other people think about that.

cu

Thomas