[news.eclipse.technology.equinox] Re: DS - Difference between component

[Daniel Bimschas <daniel@xxxxxxxxxxxx>]

Hi Andrea,

did you find an answer to your question? I'm currently stuck on a 
somewhat similar use case, trying to define a LoggerFactory that returns 
a new Logger instance for every bundle requesting one.

However, I can't find a simple example on how to use a ComponentFactory 
with DS to get a reference to a component (and the service provided by 
it) created by the ComponentFactory. Do you know of an example / tutorial?

I think there should be something like this (Warning: this is not OSGi 
specs, only what I wish it would be):

<reference name="log" interface="my.Log" cardinality="1..1" 
policy="static" bind="bindLog" unbind="unbindLog">
	<property key="loggername" value="TheLogger" />
</reference>

which uses the factory declared for the Logger service and passes the 
configuration with the attached <property> values to it. So, this is how 
I wish it to be working. But how is it working in the reality? What 
classes/interfaces need to be implemented?

I find the OSGi spec is very irritating in describing the whole 
component / service factory and DS stuff, as it's audience is OSGi 
bundle implementors as well as OSGi framework developers and there is no 
clear seperation in it.

I hope somebody of you can help me on this!

Kind regards, Daniel


Am 07.04.09 16:46, schrieb Andrea Zoppello:
> Hi All,
>
> I'm an OSGi beginner and i'm trying to understand how osgi-ds works and
> could fit my needs.
>
> I want to realize a system where i could dinamically register and
> unregister services and all of these services implements the same
> interface ( for example IStandardService ).
>
> Then suppose for examples i've two bundle A and B and each of one
> provide an implementation of this interface ( AServiceImpl, BServiceImpl).
>
> Actually i've declared a ComponentFactory in bundle A, and a
> ComponentFactory in bundle B and each of these factory provide to create
> instances of AserviceImpl and of BServiceImpl.
>
> I've used a component factory because i could have both the case:
>
> 1 - Different implementations of the same interface
> 2 - Different instances of the same implementation ( but with different
> properties ) for example a custom identifier for instances.
>
> Is this the right approach??? This question is because i've read that
> it's possible to have both ComponentFactory and ServiceFactory.
>
> I've buyed the two books about OSGi, and read the free one from neil,
> but i'm still having not clear these aspect.
>
> Is there a clear tutorial on DS ComponentFactory/ServiceFactory usage???
>
> Thanks
> Andrea Zoppello