This appendix documents features on the Spring Dynamic Modules roadmap. The design of these features specified here is subject to change. As a most up to date source, please see our issue tracker.
The current specification does not provide for access to the
ServiceReference objects for services in a managed
collection (i.e. obtained via a set or
list declaration). A future release of Spring Dynamic
Modules will provide an easy means of gaining access to these
references.
A future release of Spring Dynamic Modules may offer the following additional guarantee with respect to application context creation and start levels:
Application context creation happens asynchronously. However, the
extender bundle does guarantee that the creation of all application
contexts for bundles at start level n will be
complete before the creation of any application context at start level
m, where m > n. Care must
therefore be taken not to introduce any mandatory dependencies on
services exported by bundles with higher start levels or a deadlock will
be introduced.
In a similar vein, when shutting down the extender bundle,
application contexts at start level m will be shut
down before application contexts at start level n,
where m > n.
While support for generic and Spring-MVC web applications is available in 1.1.0, in the future we'd like to provide integration (if needed) with other popular web libraries (such as JSF and Spring Web Flow) in the upcoming releases.
Care needs to be taken when using JPA or Hibernate under OSGi as the persistence engines must have visibility of the persistent types and mapping files. The Spring Dynamic Modules project will be investigating an extension model to make managing this easier when persistent configuration is split across several bundles. See Peter Krien's blog entry on the topic for an insight into the issues.
Also, the project aims to simplify deployment of JDBC drivers and
pooling libraries that at the moment require special DynamicImport-Package.
While OSGi 4.0 is currently required, work is underway to take advantage of the new features available in 4.1. SpringSource is an active participant in the OSGi Enterprise Expert Group and we hope to help many of the ideas found in the Spring Dynamic Modules project to make their way into the OSGi R5 specification. Spring Dynamic Modules would obviously seek to support any such standards at that point in time.