spring integration + osgi

[Steven Foo]

hiya,

anyone has an example about using spring integration on osgi ?
For example having osgi bundles communicating with each other through spring integration.


Steven

[Dave Syer]

I've been working on some samples for Spring Batch which use Spring Integration and some also are OSGi enabled. I'm not ready to publish them yet because Integration is still very volatile, but if you watch the Batch forum for announcements you should see them eventually. There are two patterns I've worked on: Bundle Input Channel, and Wiring Bundle. In the former, each bundle defines only its input channel(s) and declares its outputs as OSGi service references (which are then satisfied by other bundles). In the latter (more suitable for larger applications, or ones where you might strategise the wiring to be local or remote), each bundle defines all its inputs and outputs as service references, and the wiring bundle satisfies them at runtime. N.B. in the Bundle Input Channel case you sometimes have to use cardinality="0..1" on one side of the relationship to prevent a cyclic dependency from blocking the bundles from installing. A third interesting pattern is the Hub and Spoke, where a central hub bundle has a set of dyumb routers to satisfy routing requests between spokes (so the spokes don't have to be wired directly together). We've talked about this one but not implemented it yet.