[ http://issues.apache.org/jira/browse/TUSCANY-610?page=comments#action_12427336 ] Joel Hawkins commented on TUSCANY-610: --------------------------------------
Hi Thomas. I'm trying to write up some documentation now. In short, however, the code breaks down into 2 parts: 1. The OSGi hosting of the SCA core. This is a bundle that bootstraps SCA instances for bundles that have SCA components (scdl files). The host makes a distinction between system extension and applications. For example, the OSGi binding code that supports interacting with the OSGi service framework is packaged as a system extension. The samples are packaged as applications. To me, these application instances feel like web apps. 2. The OSGi Services system extension, which in turn has two major parts: a. An OSGi Service binding, which allows SCA components to be exposed as OSGi services. This is pretty straightforward. The only tricky bit (assuming away the intricacies of SCA's wiring) is dealing with the need for a ServiceFactory during service registration. This is added to the target class using a dynamic proxy if required. b. An OSGi implementation, which wraps OSGi services as SCA components, allowing them to be wire in seamlessly (once I'm done :-) )into SCA applications. This binding allows the specification of a filter for aquiring an appropriate service reference, and acts as a service listener to clean up stale references. The code currently attempts to rebind the service if the service has changed (using the same reference) or gone away (using a different reference). Not sure if this is desirable in all cases, but it gives good demo. :-) Please remember this is an 'initial' implementation! There's enough code to get my simple scenarios working - but I'm sure there's plenty left to do. Also, the recent work that's been checked in to have some of the wiring handled by the wire service probably means some of this code can go away. Some of the things I like about the combination of SCA and OSGi is that OSGi services provide a really simple and efficient way to communicate between SCA applications running in a single OSGi instance, and OSGi's bundle isolation characteristics make dealing with multiple application deployments much more "deterministic". From my perspective (having a toe dipped in both worlds), SCA and OSGi look really complementary. I'll also try and package the rest of my eclipse environment so that you can get this running. It's mostly bundle-izing the required Tuscany jars. > Initial OSGi support effort > --------------------------- > > Key: TUSCANY-610 > URL: http://issues.apache.org/jira/browse/TUSCANY-610 > Project: Tuscany > Issue Type: New Feature > Environment: Equinox implementation of OSGi > Reporter: Joel Hawkins > Attachments: ClassloaderHook.java, OSGI-SCA.zip > > > An initial implementation of an OSGi binding for exposing SCA services as > OSGi services. > An initial implementation of an OSGi implementation for reusing OSGi services > as SCA atomic components > An OSGi-aware bootstrap environment (which can probably be reduced a bit) > A repackaging of some of the SupplyChain example > There's one class derived from an EPL-copyrighted class - I left the EPL > copyright intact. > The zip contains the samples, the OSGi binding, and a patch for the core. > Most of the patch is the OSGi launcher code. I don't think it belongs in the > core, but that's where I had it while developing. The only other bit in the > patch is a change of two of the Defaultbootstrapper's fields from private to > protected. > Also, some of the OSGi packaging for existing jars (spi, commands, etc) > aren't part of the zip. Not sure how you want to deal with the repackaging > issue. -- This message is automatically generated by JIRA. - If you think it was sent incorrectly contact one of the administrators: http://issues.apache.org/jira/secure/Administrators.jspa - For more information on JIRA, see: http://www.atlassian.com/software/jira --------------------------------------------------------------------- To unsubscribe, e-mail: [EMAIL PROTECTED] For additional commands, e-mail: [EMAIL PROTECTED]
