Eclipse Community Forums
Forum Search:

Search      Help    Register    Login    Home
Home » Eclipse Projects » Eclipse Platform » Whats going wrong?
Whats going wrong? [message #1124182] Thu, 03 October 2013 09:08 Go to next message
Ludwig Moser is currently offline Ludwig Moser
Messages: 333
Registered: July 2009
Senior Member
Hello

I started with an RCP Application and Eclipse 3.
It is supposed to grab data from a Database, modify the data and write it back to database. thats the most simple thing when it comes to software development.

we use EMF this resulted in troubles with Hibernate (loading lists was not possible).
therefore we switched to EclipseLink.
EclipseLink uses JPA, which only works with Gemini in Eclipse. Gemini is only working as we want with the extension DI. DI is using injection, which is only available in Eclipse 4.
JPA with osgi is a problem.

so i started with a simple problem, which evolved to a real monster bringing me more and more complex code with even more problems.

what is everybody else developing, as noone can help with these simple problems?
Re: Whats going wrong? [message #1125073 is a reply to message #1124182] Fri, 04 October 2013 06:08 Go to previous messageGo to next message
Ed Merks is currently offline Ed Merks
Messages: 26054
Registered: July 2009
Senior Member
Ludwig,

Comments below.

On 03/10/2013 11:08 AM, Ludwig Moser wrote:
> Hello
>
> I started with an RCP Application and Eclipse 3.
> It is supposed to grab data from a Database, modify the data and write
> it back to database. thats the most simple thing when it comes to
> software development.
It's not really all that simple to access databases via Java, so there
are lots of technology layers to hide the horrible complexity when you
want to do something more specific than a "simple" JDBC call.
>
> we use EMF this resulted in troubles with Hibernate (loading lists was
> not possible).
Did you ask Martin on the EMF newsgroup about any Teneo issues you
encountered? Or mostly you concluded that no one can use Teneo?
> therefore we switched to EclipseLink.
So clearly you want something more than just JDBC...
> EclipseLink uses JPA, which only works with Gemini in Eclipse.
I thought Teneo also used that and I know that Teneo provides
EclipseLink integration, although I'm not sure must has been invested
into that over the past years...
> Gemini is only working as we want with the extension DI. DI is using
> injection, which is only available in Eclipse 4.
> JPA with osgi is a problem.
Oh, and EclipseLink didn't solve that and their forum wasn't able to get
you started, so mostly you concluded that no one can use EclipseLink?
>
> so i started with a simple problem, which evolved to a real monster
> bringing me more and more complex code with even more problems.
Perhaps a more general forum such as StackOverflow will produce more
general answers...
>
> what is everybody else developing, as noone can help with these simple
> problems?
You asked for help and didn't get it?
Re: Whats going wrong? [message #1125094 is a reply to message #1125073] Fri, 04 October 2013 06:30 Go to previous messageGo to next message
Ludwig Moser is currently offline Ludwig Moser
Messages: 333
Registered: July 2009
Senior Member
i do not say people are not able to use this or that tool.
I'm not using teneo.
EclipseLink, JPA, Gemini, Gemini DI.

i'm just wondering noone else runs into the problems i get, as what i do seems pretty simple to me.
eg: EclipseLink uses Refreshing for Lazy loading (weaving)
when you use Gemini DI you need to disable refreshing, because otherwise your UI freezes.
afaik EclipseLink was TopLink before, so it should be a mature piece of code. we were able to find several bugs (they got confirmed (and new))

i am not moaning about these tools, as i am happy someone already did it.
but as noone else found these problems i wonder how/what other people are developing.
is everybody (who is using java and eclipse) out for web development.

i'm not asing for help (directly).
i just try to find out if i choose the wrong way (wrong tools) to reach my goal.

DataBase access with lazy loading in osgi (with an emf based model) <- thats what i need

EDIT: i now got dbaccess working, but lazy loading still fails

[Updated on: Fri, 04 October 2013 06:30]

Report message to a moderator

Re: Whats going wrong? [message #1125104 is a reply to message #1125094] Fri, 04 October 2013 06:44 Go to previous messageGo to next message
Ed Merks is currently offline Ed Merks
Messages: 26054
Registered: July 2009
Senior Member
Ludwig,

Comments below.

On 04/10/2013 8:30 AM, Ludwig Moser wrote:
> i do not say people are not able to use this or that tool.
No, I was just reading below the lines...
> I'm not using teneo.
But you said you tried it and it didn't work.
> EclipseLink, JPA, Gemini, Gemini DI.
>
> i'm just wondering noone else runs into the problems i get, as what i
> do seems pretty simple to me.
Yes, I can see how sometime you wonder how anyone is able to use some
technology. That's like when I looked at http://eclipse.org/lyo/ and
found out that they don't provide OSGi bundles at all? So how does
anyone use this to build an Eclipse application. Goodness only
knows... Apparently no one uses it to build Eclipse applications. So
what kind of applications is it used to build? Goodness only knows...
> eg: EclipseLink uses Refreshing for Lazy loading (weaving)
> when you use Gemini DI you need to disable refreshing, because
> otherwise your UI freezes.
> afaik EclipseLink was TopLink before, so it should be a mature piece
> of code.
Yes, that's definitely the case.
> we were able to find several bugs (they got confirmed (and new))
>
> i am not moaning about these tools, as i am happy someone already did it.
Yes, a free lunch doesn't imply it tastes good, and of course if it
doesn't you could like for another one or find somewhere to buy it, in
which case you could complain that it's full of bugs and ask for a refund.
> but as noone else found these problems i wonder how/what other people
> are developing.
> is everybody (who is using java and eclipse) out for web development.
Perhaps everyone else when they run into the "my UI freezes" issue they
change their code so whatever is very slow isn't done on the UI thread...
>
> i'm not asing for help (directly).
> i just try to find out if i choose the wrong way (wrong tools) to
> reach my goal.
>
> DataBase access with lazy loading in osgi (with an emf based model) <-
> thats what i need
You might try CDO; it pretty much has an optimal laziness design, with a
huge advantage that most of this is completely transparent to the rest
of the application working directly with the model... I think it has
alternative back ends you could try. You should also ensure/confirm
that your Teneo problems don't already have a simple solution...
>
> EDIT: i now got dbaccess working, but lazy loading still fails
Re: Whats going wrong? [message #1125520 is a reply to message #1125104] Fri, 04 October 2013 16:00 Go to previous messageGo to next message
Thorsten Schlathölter is currently offline Thorsten Schlathölter
Messages: 208
Registered: February 2012
Location: Düsseldorf
Senior Member
Hi,
I used Teneo/Hibernate/Eclipse Gemini in a project a couple of month ago. It worked like a charm. I don't know what "loading lists was not possible" means. Surely the setup can deal with lists and lazy loading is a central feature in hibernate.

Regards,
Thorsten
Re: Whats going wrong? [message #1130150 is a reply to message #1125520] Wed, 09 October 2013 09:05 Go to previous message
Ludwig Moser is currently offline Ludwig Moser
Messages: 333
Registered: July 2009
Senior Member
again, i am NOT using teneo.
loading lists with teneo works (you can get size() without causing it to load all subobjects on your objects in the list)
because it does not use emf notifications (does not extend eobjects)

loading lists 'works' with hibernate and EMF, BUT. if you only want the size of it, you need another statement. otherwise the whole list gets sucked out of the database including subobjects - even with lazy loading enabled.

the stuff about UI freezes is not grown in my head - this is an answer from another developer (Gemini DI plugin)

to me it looked like
o emf is supposed to work within a RCP
o eclipselink is supposed to work within a RCP
o gemini is supposed to work within a RCP
o gemini di is supposed to work within a RCP

so it was obvious to use it in an Eclipse RCP app

finally:
please close or delete this thread,
as it does not seem to get anything helpful
seems the opposite way, getting people angry, which was absolutely NOT my intention.
Previous Topic:Plugin/feature to show inherited javadoc inline in editor
Next Topic:Controlling access of packages
Goto Forum:
  


Current Time: Sun Sep 21 22:20:53 GMT 2014

Powered by FUDForum. Page generated in 0.02109 seconds
.:: Contact :: Home ::.

Powered by: FUDforum 3.0.2.
Copyright ©2001-2010 FUDforum Bulletin Board Software