Re: [platform-core-dev] Question about initializing the new message cata

[Thomas Watson <tjwatson@xxxxxxxxxx>]

> In the snippets given for initializing the Messages class, it calls
a 
> class in the OSGi layer, passing the message bundle name and the Messages
> class object, where these are in some higher-level plug-in.
> 
> import org.eclipse.osgi.util.NLS;
> ...
> private static final String BUNDLE_NAME = 
> "org.eclipse.core.utils.messages"; //$NON-NLS-1$
> static {
>    NLS.initializeMessages(BUNDLE_NAME, Messages.class);
> }
> 
> 
> How does the NLS class resolve the message bundle?  In traditional
eclipse 
> plug-in visibility rules, lower-level plug-ins can't see classes or
> resources from higher-level plug-ins.
> Is this using the 'Import-Package: *' capability of OSGi?  I
didn't see 
> this in org.ecillpse.osgi's manifests.
> 
> Just curious as to how this works,
> Nick
> 

We use the classloader of the class object which is
passed into initializeMessages
to find the resource properties files.  This
allows us to load the resources
of higher-level plug-ins.

FYI, the system bundle (org.eclipse.osgi) cannot import
any packages because 
it provides the delegation model for all the other
bundles.  The classloader
of the framework is a "normal" classloader
that has no knowledge of the OSGi
classloader delegation model.  This means it
cannot load any classes from
an imported package or from a required bundle.

Tom