Some integration questions

[Stefan Arentz <st...@gmail.com>]

When OpenJPA is used in a Spring 2.0 environment that is deployed in
say Jetty 6.0, does that count as a J2EE or J2SE environment?

OpenJPA works with 'enhanced' classes. If I want do not want to run
with an JVM agent or pre-compile/enhance my classes then it needs to
be done at runtime. Actually, at class loading time. Right?

Is it technically possible to create a war file that without servlet
container support contains code to correctly enhance classes? Or does
this always need help from the code (in the container) that is
actually loading the .war file and it's containing classes and .jar
files?

 S.

Re: Re: RE: Some integration questions

[Stefan Arentz <st...@gmail.com>]

What I forgot to mention is that I start Jetty from IDEA using a
simple main() that basically does a "new Server().start()". Maybe this
makes a difference for classloading?

 S.

Re: RE: Some integration questions

[Stefan Arentz <st...@gmail.com>]

On 10/7/06, Patrick Linskey <pl...@bea.com> wrote:

...

Patrick, thanks for the hints.

> Also, in the specific case (Spring 2.0 + Jetty), you'll get
> auto-enhancement out-of-the-box, modulo any bugs that haven't been
> surfaced yet by us or the Spring team (thanks, Costin!).

That is also the reason why I am trying to understand how all the
pieces fit together. I'm currently in a situation where I keep getting
the following error:

 the type "class wicket.quickstart.entities.Message" has not been enhanced.

even though I see the following in the OpenJPA TRACE log:

4296  INFO   [btpool0-6] openjpa.MetaData - Found 1 classes with
metadata in 0 milliseconds.
4459  TRACE  [btpool0-6] openjpa.Enhance -
"wicket/quickstart/entities/Message" requires runtime enhancement:
true
4541  TRACE  [btpool0-6] openjpa.MetaData - Loading metadata for
"class wicket.quickstart.entities.Message" under mode "[META][QUERY]".
4559  INFO   [btpool0-6] openjpa.MetaData - Parsing class
"wicket.quickstart.entities.Message".
4559  INFO   [btpool0-6] openjpa.MetaData - Parsing package
"wicket.quickstart.entities.Message".
4578  TRACE  [btpool0-6] openjpa.MetaData - Generating default
metadata for type "wicket.quickstart.entities.Message".
4578  TRACE  [btpool0-6] openjpa.MetaData - Using reflection for
metadata generation.
4596  TRACE  [btpool0-6] openjpa.MetaData - Set persistence-capable
superclass of "wicket.quickstart.entities.Message" to "null".
4596  TRACE  [btpool0-6] openjpa.MetaData - Resolving metadata for
"wicket.quickstart.entities.Message@5779080".
4596  TRACE  [btpool0-6] openjpa.MetaData - 	Resolving field
"wicket.quickstart.entities.Message@5779080.id".
4604  TRACE  [btpool0-6] openjpa.MetaData - 	Resolving field
"wicket.quickstart.entities.Message@5779080.text".
4606  TRACE  [btpool0-6] openjpa.Enhance - Enhancing type "class
wicket.quickstart.entities.Message".

I'm not sure this is a Spring issue or an OpenJPA issue though. That
is why I'm trying to understand how all this should work.

(I'm trying to build a quickstart project for http://wicket.sf.net
that uses OpenJPA and Spring)

 S.

Re: Some integration questions

[Craig L Russell <Cr...@Sun.COM>]

Hi,

On Oct 7, 2006, at 1:55 AM, Patrick Linskey wrote:

>> When OpenJPA is used in a Spring 2.0 environment that is deployed in
>> say Jetty 6.0, does that count as a J2EE or J2SE environment?
>
> I'm going to stay far far away from any attempts to define what
> constitutes a J2EE environment. Or a Java EE environment, for that
> matter.

Both J2EE (1.4 and earlier) and Java EE (5 and later) define an  
environment that provides a wide range of services, including but not  
limited to, a web container, a CMP container, management, naming  
services, ORB services, and several other JSRs. There is no similar  
definition of a "web server" in this world.

I'm not an expert in Jetty, but it seems to be "just a component"  
that is intended for integration with other products to provide a  
complete solution. So it doesn't appear to be even close to a Java EE  
server.

So you will usually be correct if you think of a web container as  
operating in a Java SE, not a Java EE environment.

Craig

Craig Russell
clr@apache.org http://db.apache.org/jdo

RE: Some integration questions

[Patrick Linskey <pl...@bea.com>]

> When OpenJPA is used in a Spring 2.0 environment that is deployed in
> say Jetty 6.0, does that count as a J2EE or J2SE environment?

I'm going to stay far far away from any attempts to define what
constitutes a J2EE environment. Or a Java EE environment, for that
matter.

However, I think that the answer to your question is "approximately Java
EE". The JPA spec defines a contract between itself and a "container".
The spec implies that this is an EJB container, but really, the contract
is between the JPA persistence provider and a "persistence container".
That persistence container is responsible for doing a number of things.
Spring 2.0 is a persistence container.

> OpenJPA works with 'enhanced' classes. If I want do not want to run
> with an JVM agent or pre-compile/enhance my classes then it needs to
> be done at runtime. Actually, at class loading time. Right?

Correct.

> Is it technically possible to create a war file that without servlet
> container support contains code to correctly enhance classes? Or does
> this always need help from the code (in the container) that is
> actually loading the .war file and it's containing classes and .jar
> files?

In the general case, it should be technically possible -- just do some
classloading work in the war file. However, I expect more and more
servlet containers to become persistence containers. 

Also, in the specific case (Spring 2.0 + Jetty), you'll get
auto-enhancement out-of-the-box, modulo any bugs that haven't been
surfaced yet by us or the Spring team (thanks, Costin!).

-Patrick
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