Java Reference
In-Depth Information
Apache ServiceMix
Apache ServiceMix is the most popular open source implementation of the JBI 1.0 specifica-
tion. Because it implements JBI, all messages within ServiceMix are serialized to XML, fol-
lowing the normal form defined by the container. Classes that you write to represent your in-
tegration logic in ServiceMix have a variety of dependencies on the ServiceMix framework.
The ServiceMix project is very active, and as of this writing, the project team is working to
deliver ServiceMix 4, which will incorporate many of the features that are charted for the JBI
2.0 specification (even before it is released).
Extensibility
Like Mule, ServiceMix can be readily integrated with Spring. ServiceMix also uses OSGi,
which offers another clear and simple way that the bus can provide extensibility to developers.
NOTE
OSGi represents a framework that defines an application life cycle management model, a runtime en-
vironment, a service registry, and the idea of bundles and modules. A module represents a collection
of declared dependencies, which hides its internals behind well-defined interfaces to encourage reuse
and freedom to change.
OSGi is a specification of the OSGi Alliance, a nonprofit organization, which you can visit at
ht-
Deployment in ServiceMix
ServiceMix is somewhat less lightweight than Mule at deploy time. In order to deploy a
simple class that represents some functionality you want to make available on the ESB, you
need to create a service assembly (SA) that contains service units, following the JBI specific-
ation. You can use either Ant or Maven 2 to create the SAs for you. If you're using Maven 2,
there are a great number of pre-existing project archetypes written specifically for ServiceMix
that you can take advantage of. NetBeans 6 makes these readily available via the New Project
wizard, as shown in
Figure 14-5
.
