On Tue, Aug 22, 2017 at 8:50 AM, Bram Pouwelse <b...@pouwelse.com> wrote:
> Hi all, > > I have some questions about the "Additional JAX-RS types" section of the > JAX-RS-Services RFC (rfc-217). > > 5.2 Additional JAX-RS types: > … > *"Extensions should provide an osgi.jaxrs.application.select property with > a filter that will match application to which this extensions will be > registered. If no such filter is provided the extension will affect the > default application." * > … > > > 5.2.5 Depending on Extension Services: > > > *"When writing and configuring a JAX-RS resource or extension it is > possible for one extension to depend on another. For example a JAX-RS > resource may have a dependency upon a MessageBodyWriter to provide JSON > serialization, or a ContainerRequestFilter may depend on a ContextResolver > to provide injected configuration.* > > > *In these cases it is necessary to express a dependency on the existence > of an extension within the JAX-RS container. This can be expressed on any > JAX-RS whiteboard service using the osgi.jaxrs.extension.select property. > This property has type String+ and contains a list of LDAP filters. These > filters will be run against the service properties of each extension > service registered with the container. If all of the supplied filters pass > then the whiteboard service will registered. This extension checking should > be done per Application.* > *If at some point later a necessary extension service dependency becomes > unavailable then the whiteboard service will become ineligible for > inclusion in the JAX-RS container until a suitable replacement is found."* > > > Questions: > > - Is there a way to register extension services without actively > adding them to an application (just have them ready to use for those who > need them)? > > Use an `*osgi.jaxrs.application.select` filter than matches all applications:* *e.g. **osgi.jaxrs.application.select=*(osgi.jaxrs.name=*) > > - > - Is it possible to use an extension service from an application that > doesn’t match the extension service’s osgi.jaxrs.application.select filter? > > No, since the jax-rs service's extension bindings must come from within those bound to the same application! > > - > - The "This extension checking should be done per Application" remark > shoud that also apply to the default application? Sounds ok to me for > JAX-RS applications that are registered as such but for the default > application this is kind of strange as a single resource depending on an > unavailable extension could make the whiteboard go down for all JAX-RS > resources (that are not part of an application)? > > Resources which are static need to use static extensions. The spec is only talking about jaxrs "services". Otherwise statically wired resources within a given application are not subject to OSGi services, except from purely the shadowing perspective, not from the wiring/class space perspective. If you're talking about something else could you please elaborate? > > - I think for the default application just excluding the resource with > unstatisfied dependencies would be better than taking the default > application down. > > At no point does an application get taken down due to a resource/extension not being satisfied... unless it's the application itself has the extension dependency. But the default application has no such dependencies, in fact it may have no resources either. HTH - Ray > > - > > Regards, > Bram > > _______________________________________________ > OSGi Developer Mail List > osgi-dev@mail.osgi.org > https://mail.osgi.org/mailman/listinfo/osgi-dev > -- *Raymond Augé* <http://www.liferay.com/web/raymond.auge/profile> (@rotty3000) Senior Software Architect *Liferay, Inc.* <http://www.liferay.com> (@Liferay) Board Member & EEG Co-Chair, OSGi Alliance <http://osgi.org> (@OSGiAlliance)
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