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From Tommaso Teofili <tommaso.teof...@gmail.com>
Subject Re: UIMA module thoughts (and refactoring)
Date Wed, 31 Aug 2011 16:11:48 GMT
the dynamic-imports way was taken in consideration when talking with other
UIMA mates, but I haven't inspected that possibility yet.
Thanks Reto.
Cheers,
Tommaso

2011/8/31 Reto Bachmann-Gmür <me@farewellutopia.com>

> Hi Tommaso
>
> Without knowing about the details I'm wondering if this extension
> class loader defined when instantiating the UIMA framework cannot be
> the Bundle-Class-Loader with the Bundle having a dynamic-import
> directive.
>
> I'm very much looking forward to the 'Getting started with Clerezza
> and UIMA' page :)
>
> Cheers,
> Reto
>
> On Wed, Aug 31, 2011 at 4:48 PM, Tommaso Teofili
> <tommaso.teofili@gmail.com> wrote:
> > Hi all,
> > the UIMA Addons 2.3.1 release happened on August 29th [1], this release
> > didn't include the OSGi packaging for the annotators since the UIMA
> > community wants to provide full support to OSGi in the future while the
> > addons OSGi packaging allowed only some basic use cases to be executed.
> >
> > So far the bad news, the good news is that we can now include UIMA Addons
> > artifacts in our modules and that there is already a solution to face the
> > possible issues with class loading within a framework which is not fully
> > OSGi compliant.
> >
> > The UIMAFramework class creates an AnalysisEngines given its (XML)
> > descriptor that contains the FQN of the annotator class which is then
> > instantiated via Class.forName().
> > As far as I've experienced this is not good when working within OSGi
> > containers as each bundle uses a separate ClassLoader so, for example,
> the
> > ClassLoader of the uima.utils bundle cannot see the ClerezzaCASConsumer
> > class in uima.casconsumer module by default.
> > Luckily UIMA provides the possibility of defining an extension
> ClassLoader
> > when instantiating the framework.
> > So the idea is to define an ExtensionClassLoader which registers the
> > ClassLoaders of UIMA classes implementing AnalysisComponent interface
> (that
> > is the interface for Annotators and CAS Consumers) and use it within the
> > creation of each AnalysisEngine.
> > Each bundle which has annotator classes can automatically register its
> > classes (in the ExtensionClassLoader) using an OSGi Activator (a
> > UIMABundleActivator in the maven-bundle-plugin configuration) which is
> > responsible for this task.
> >
> > Obviously in the future releases of UIMA with full OSGi support the above
> > constraints could be safely removed.
> >
> > So my idea is to apply the above changes in order to allow easy deploy of
> > custom UIMA pipelines within Clerezza. After that I think a brief
> 'Getting
> > started with Clerezza and UIMA' page would be useful.
> > Looking forward to your feedback.
> > Cheers,
> > Tommaso
> >
> > [1] : http://uima.apache.org/downloads.cgi
> >
>

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