How do I create a JGroups channel in JBoss 7.x from the configuration in the standalone.xml file?

Question

I am writing an OSGI service for JBoss7.x and I need to create a new JChannel for some domain related RPC. I would like to use one of the protocol stack definitions from the standalone.xml file and will want to use shared transport if I can.

I don't know where to begin to access the information or how to inject it either.

Looking at the JBoss AS code I think I probably need to get hold of a JChannelFactory instance. How would I do this in OSGI?

Answer 1

Not sure if it's the recommended approach but it does work.

First, get a reference to the JBoss Modular Service Container. This can be looked up in the OSGI service registry. Using Spring DM/Blueprint:

<osgi:reference id="serviceContainer" interface="org.jboss.msc.service.ServiceContainer" />

In your code use the service container to look up a given service by name:

ServiceName sn = ServiceName.of("jboss", "jgroups", "stack", "udp");
ServiceController<?> serviceController = serviceContainer.getService(sn);

if (serviceController == null) {
    throw new RuntimeException("Failed to lookup service controller for jboss.jgroups.stack.udp");
}

Service<?> service = serviceController.getService();
Object obj = service.getValue();

ChannelFactory factory = (ChannelFactory) obj;

If you need to know the service names that are available then call dumpServices() on the ServiceContainer to get a list in the log file.

If using Maven then add a dependency upon the JBoss MSC in your pom file:

<dependency>
    <groupId>org.jboss.msc</groupId>
    <artifactId>jboss-msc</artifactId>
    <version>1.0.2.GA</version>
</dependency>

plus any other dependencies you may need in order to access the code used by the service. In the example above there is a need for a dependency upon the org.jboss.as/jboss-as-clustering-jgroups and org.jgroups/jgroups libraries in the pom file.

You also need to make sure that these services are defined as capabilities in the standalone.xml file:

<capability name="org.jgroups"/>
<capability name="org.jboss.as.clustering.jgroups"/>