OSGI: How to update a 'consumer' bundle

Question

I have been trying to understand a strange OSGI behavior. Hoping someone can shed some light on it. Here is my setup

1) Using eclipse\plugins\org.eclipse.osgi_3.7.0.v20110613.jar

2) I have a Bundle that exports a service (HelloworldService)

It registers the service in the activator as such

    public void start(BundleContext context) throws Exception {

        IHelloService helloService = new HelloServiceImpl();
        helloServiceRegistration =context.registerService(
                                  IHelloService.class.getName(), helloService, null
);


    }

3) I have a 'consumer' bundle that uses the service via a ServiceTracker

        ServiceReference externalServiceReference = Activator.getContext().getServiceReference(IHelloService.class.getName());
        IHelloService externalService = (IHelloService) Activator.getContext().getService(externalServiceReference);

Now when I deploy both these jars to OSGI (helloworld.jar and helloworldservice.jar); it works fine. I am able to get a 'IHelloService' impl object and make calls on it. I can start/stop the bundles and when they come back; it works just fine

The problem happens when I 'uninstall' and then 'install' the HelloWorldservice bundle. In that case; the 'Helloworld' consumer externalServiceReference is NULL. If I view the bundle info; I see this

osgi> bundle 1
mypackage.helloworld_1.0.0.qualifier [1]
  Id=1, Status=RESOLVED    Data Root=C:\Users\\dev\eclipse\plugins\configuration\org.eclipse.obundles\1\data
  No registered services.
  No services in use.
  No exported packages
  Imported packages
    mypackage.helloworldservice; version="0.0.0" **stale**
    org.osgi.framework; version="1.6.0"
    org.osgi.util.tracker; version="1.5.0"
  No fragment bundles
  Named class space
    mypackage.helloworld; bundle-version="1.0.0.qualifier"[provided]
  No required bundles

Notice that its 'imported packages' has GONE STALE. Here is the line in question

Imported packages mypackage.helloworldservice; version="0.0.0"<stale>

Now I can fix this by issuing an 'update' command from the console.

Here is my question

1) How do I programatically do this from within my 'consumer' bundle.. 2) If I am on a production system and I deploy a new 'copy' of the helloworlservice.jar (replacing the existing version); Do I have to update all its users.. I thought the ServiceTracker would give me the service on the fly

Thanks

Answer 1

The consumer bundle imports the mypackage.helloworldservice package from the service jar. When you uninstall the service jar, the consumer jar is still wired to the now stale package from the uninstalled service jar. When you install a new service jar, it exports a new "copy" of the mypackage.helloworldservice package (I suspect the service jar does not also import the mypackage.helloworldservice package). So you need to refresh the consumer jar to get it to wire to the new mypackage.helloworldservice package.