-----Original Message-----
From: Chantale Caron [mailto:[EMAIL PROTECTED]]
Sent: November 22, 2002 1:52 PM
To: Graham Lounder
Subject: Re: FW: Modifying ClassDescriptor
Could you send this on the mailing list for me
Thanks
Thank you very much Armin, your suggestion was a great help to me. I
still have to test my new code
to make sure that everything works great though. Just to make sure that
I'm loading the repository correctly is this something like what you had
in mind for the readFromRepository method?
public DescriptorRepository readFromRepository(PBKey pbKey)
{
DescriptorRepository descriptor = null;
try{
RepositoryPersistor persistor = new RepositoryPersistor();
descriptor =
persistor.readFromFile(pbKey.getRepositoryFile());
}catch(Exception exc){
}
return descriptor;
}
Thanks
Graham Lounder wrote:
>
> -----Original Message-----
> From: Armin Waibel [mailto:[EMAIL PROTECTED]]
> Sent: November 22, 2002 11:22 AM
> To: OJB Users List
> Subject: Re: Modifying ClassDescriptor
>
> Hi Graham,
>
> ----- Original Message -----
> From: "Graham Lounder" <[EMAIL PROTECTED]>
> To: "OJB Users List" <[EMAIL PROTECTED]>
> Sent: Friday, November 22, 2002 3:17 PM
> Subject: Modifying ClassDescriptor
>
> > I'm fairly new to This API and I have some questions regarding the
> > ClassDescriptor.
> >
> > I'll first describe what I'm trying to achive ( if it's even possible
> to do
> > this)
> >
> > I've setup my repository_user.xml file to do cascade_delete = true for
> most
> > objects, but sometimes the user of the application may not want to
> cascade
> > delete. I added a boolean variable to my methods to check if the user
> wants
> > to cascade delete or not. If the user doesn't want to cascade delete,
> I was
> > pulling out the ClassDescriptor object from the instance of the broker
> and
> > modifying the ObjectReferenceDescriptors and the CollectionDescriptors
> to
> > cascade-delete=false. Now once my operation is complete, I noticed
> that the
> > broker kept the modifications. I tried to get a copy of the original
> > ClassDescriptor to reset it on the broker before closing it but failed
> this
> > attempt.
> >
> > I'm not really sure at this point how the ClassDescriptor information
> is
> > stored in memory.
>
> A few days ago, Thomas and I discuss (offline) the theme
> "runtime repository changes" with the result that we have to do
> a re-organistation of the repository stuff. We want to make it possible
> to select between a 'perThread' and a 'global' modification of the
> DescriptorRepository/ClassDescriptor/...
> Any comments are welcome.
>
> Currently each PBKey has a associated DescriptorRepository. All PB
> with the same PBKey share the same DescriptorRepository. Thus if you
> modify a ClassDescriptor, the changes take effect over all PB instances
> with
> the same PBKey, no good when run in multi-threaded environment.
>
> A quick and dirty solution of your problem could be:
> Add public method
> DescriptorRepository#readFromRepository(PBKey pbKey)
> This method returns a copy of the repository.
> Extent PersistenceBrokerImpl and add method
> setRepository(DescriptorRepository repository)
> {
> this.descriptorRepository = repository;
> }
> Now you are able to change the repository of a single PB instance.
> Get a copy, set the copy, modify the copy, do your work,
> restore the old repository reference (for better performance: undo
> modification on copy, keep copy in memory).
>
> HTH
>
> I could add a public
> DescriptorRepository#readFromRepository(PBKey pbKey)
> method to CVS if you think this could be useful for you.
>
> regards,
> Armin
>
> > I also tried for fun to create another instance of the
> > broker inside this method and pull the ClassDescriptor as well to see
> if it
> > would be modified when I modified the other one and in deed it is
> being
> > modified. This seems to tell me that all the brokers shared the safe
> > reference to the ClassDescription object representing the mapping of
> the xml
> > file.
> >
> > I was able to reload the file and get the original version and set it
> on the
> > broker once I finished my operation. But wouldn't this also modify
> any
> > other broker in progress and hence not give the user the results he is
> > looking for in the end.
> >
> > I would really appreciate any help or information concerning this
> issue.
> >
> > Thanks
> >
> > ============================================
> > Graham Lounder
> > Java Developer
> > Spatial Components Division
> > CARIS
> > 264 Rookwood Ave
> > Fredericton NB E3B-2M2
> > Office 506 462-4263
> > Fax 506 459-3849
> > [EMAIL PROTECTED]
> > http://www.spatialcomponents.com
> > ============================================
> >
> >
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> >
> >
>
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--
Chantale Caron
Java Developer
Caris Spatial Components
Tel: (506)462-4273
Fax: (506)459-3849
email: [EMAIL PROTECTED]
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