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Re: [eclipselink-users] EclipseLink in OSGi environment
Hi Tom, 

The idea with the EntityManagerFactoryBuilderService would be that you could retrieve the database credentials from the same place. 

Just to make sure I got it right: I could e.g. create my own IDatabaseCredentialsService with one method getDBCredentials() : Map<String, String>. Afterwards I would inject this service everywhere I am using a persistence unit specific EntityManagerFactoryBuilderService. So rather providing redundant information as posted below I would retrieve them from the same place/my IDatabaseCredentialsService. 

This solution will produce a little bit overhead with the service bindings but ok, I can live with it.

Perhaps I do not completely understand the problem you are facing. Do you have an example of how you would do this outside of OSGi?
Unfortunately I don't have an example outside of OSGi, in our current project OSGi is fixed as the technology platform.

Eugen

Am 29.11.2011 um 16:01 schrieb Tom Ware:

The idea with the EntityManagerFactoryBuilderService would be that you could retrieve the database credentials from the same place.  I guess you could think of the fact that you have to pass them in to both getEntityManagerFactory() calls as redundant, but I'm not sure that's how I think about it.

Perhaps I do not completely understand the problem you are facing. Do you have an example of how you would do this outside of OSGi?

-Tom

On 29/11/2011 9:52 AM, Eugen Reiswich wrote:
I took a look at the EntityManagerFactoryBuilderService. As I understand there
is one instance of that class for each persistence unit. So again I would have
to provide that instance redundant data base credentials like:

ServiceReference[] refs =
   context.getServiceReferences(
       EntityManagerFactoryBuilder.class.getName(),
       "(osgi.unit.name=Accounting)");

if (refs != null) {
    EntityManagerFactoryBuilder emfBuilder =
        (EntityManagerFactoryBuilder) context.getService(refs[0]);
    if (emfBuilder != null) {
        Map<String,Object>  props = new HashMap<String,Object>();
        props.put("javax.persistence.jdbc.user", username1);
        props.put("javax.persistence.jdbc.password", password1);
        props.put("javax.persistence.jdbc.url", url1);

        EntityManagerFactory accountingEMF =
            emfBuilder.createEntityManagerFactory(props);


The same code I would need to write for all other persistence units e.g.
customers, orders. This is exactly what I would like to avoid. Any other hints?

Eugen

Am 28.11.2011 um 20:43 schrieb Tom Ware:

Take a look at the EntityManagerFactoryBuilder Service. Some docs on this page:

http://wiki.eclipse.org/Gemini/JPA/Documentation/JPAServices

On 28/11/2011 1:39 PM, Eugen Reiswich wrote:
Hi Tom,

thanks for the jump start. After reading the documents there is one question I
was not able to answer yet. In my outlined scenario I would like to put
everything related to JPA in corresponding DAO bundles. As far as I understood
my bundles will contain the following JPA related files:

**.service.customer.dao*
- customer-mapping.xml
- persistence.xml

**.service.account.dao*
- account-mapping.xml
- persistence.xml

Both persistence.xml files contain duplicate database credentials. How can I
provide those only once?

Eugen


Am 24.11.2011 um 18:58 schrieb Tom Ware:

The best place to get started is the Gemini project. It includes the reference
implementation for a number of Java EE technologies in OSGi.

http://www.eclipse.org/gemini/

The base of the JPA part of the project is here:

http://www.eclipse.org/gemini/jpa/

Documentation is on the wiki:

http://wiki.eclipse.org/Gemini/JPA/Documentation

-Tom


On 24/11/2011 12:20 PM, Eugen Reiswich wrote:
Hi folks,

I googled now for two days to find an appropriate OSGi + EclipseLink example,
but only found very basic ones.

I've got an OSGi application with the following architecture:

*Bundles:*
*.ui.customer
*.ui.account

*.domain.customer // business objects like Customer.java, Address.java etc.
*.domain.account // business objects like Account.java

*.service.customer // customer logic
*.service.account

*.service.customer.dao // persistence logic
*.service.account.dao

Using this architecture I would like to:
- use ORM.XML files in my *.dao-bundles rather that annotations in my business
objects. This should keep my business objects and domain bundles free of any
technology.
- I would like to provide one DB-Connection credentials. I understand that a
persistence.xml contains both: the persistence unit and DB-connection
information. In my example I would need two persistence.xml files for customer
and account bundles providing DB-connection information twice. Right?

*My questions are:*
1. assuming the above requirements/architecture what's the best way to make
this
work with EclipseLink + JPA 2.0?
2. where do I have to put the persistence.xml file(s)?
3. How can I tell EclipseLink that my DAO-bundles provide ORM mapping files?

Regards,
Eugen


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________________________

Dipl. Wi-Inf. Eugen Reiswich


Universität Hamburg (UHH)
Fakultät für Mathematik, Informatik
und Naturwissenschaften (MIN-Fakultät)

Department Informatik
Zentrum für Architektur
und Gestaltung von IT-Systemen (AGIS)

Vogt-Koelln-Str. 30
22527 Hamburg

Tel: 040 / 42883 - 2307




_______________________________________________
eclipselink-users mailing list
eclipselink-users@xxxxxxxxxxx
https://dev.eclipse.org/mailman/listinfo/eclipselink-users
_______________________________________________
eclipselink-users mailing list
eclipselink-users@xxxxxxxxxxx
https://dev.eclipse.org/mailman/listinfo/eclipselink-users

________________________

Dipl. Wi-Inf. Eugen Reiswich


Universität Hamburg (UHH)
Fakultät für Mathematik, Informatik
und Naturwissenschaften (MIN-Fakultät)

Department Informatik
Zentrum für Architektur
und Gestaltung von IT-Systemen (AGIS)

Vogt-Koelln-Str. 30
22527 Hamburg

Tel: 040 / 42883 - 2307




_______________________________________________
eclipselink-users mailing list
eclipselink-users@xxxxxxxxxxx
https://dev.eclipse.org/mailman/listinfo/eclipselink-users
_______________________________________________
eclipselink-users mailing list
eclipselink-users@xxxxxxxxxxx
https://dev.eclipse.org/mailman/listinfo/eclipselink-users

________________________
Dipl. Wi-Inf. Eugen Reiswich

Universität Hamburg (UHH)
Fakultät für Mathematik, Informatik 
und Naturwissenschaften (MIN-Fakultät) 
Department Informatik                        
Zentrum für Architektur                         
und Gestaltung von IT-Systemen (AGIS)
Vogt-Koelln-Str. 30                             
22527 Hamburg
Tel: 040 / 42883 - 2307

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