Hi Vinicius,

Glad to help, and thanks for your kind comments about my book.

However I think it's the authors of "OSGi in Action" who are asking
for a book review at the moment, since they have just released some
chapters for early access. They are on this mailing list so can
probably clarify. My book is "OSGi in Practice". Yes, these two titles
are confusingly similar... my defence is that I started writing my
book first!

Kind regards,
Neil

On Thu, Jan 29, 2009 at 4:45 PM, Vinicius Carvalho
<[email protected]> wrote:
> Bullseye! Thanks Neil. I've tested and got a ClassCastException ...
>
> We'll look into our code and check why is this happening. We've just tried,
> and in a debug breakpoint we've seen that the service returned by:
>  HttpService httpService = (HttpService)
>  context.getService(reference);
>
> Was indeed HttpServiceImpl, I guess we have a classloader problem. We have
> the equinox servletbridge inside webinf/lib, hence it's loaded by
> WebApplicationClassLoader. Since this bundle is loaded by ContextClassLoader
> that might be the problem, we don't know.
>
> I'll look into it. Thanks a lot for your help, it gave us hope again :)
>
> I owe you a book review (from your message at twitter.com). I've finished
> you book btw, best chapter is chapter 6 (concurrency is a subject that is
> not very well explained in most books, which is a shame since it lead to
> really annoying problems) Promise to write a few lines of revuew to you
> soon.
>
> Regards
>
>
> On Thu, Jan 29, 2009 at 11:57 AM, Neil Bartlett <[email protected]>wrote:
>
>> It's possible that the HttpService published in the service registry
>> is not compatible with your bundle that is trying to track it. This
>> could happen if you have multiple bundles exporting the
>> org.osgi.service.http package, or if your tracking bundle has somehow
>> included the org.osgi.service.http package instead of importing it.
>>
>> To check if this is the case, try changing the start() method of your
>> Activator to call httpServiceTracker.open(true) rather than just
>> httpServiceTracker.open(). This will force the tracker to find all
>> HttpServices, even the incompatible ones. Of course you will soon get
>> a ClassCastException when you try to use the returned service, so you
>> need to fix the underlying problem. Doing this will simply tell you if
>> that is indeed the problem.
>>
>> Regards,
>> Neil
>>
>> On Thu, Jan 29, 2009 at 1:48 PM, Vinicius Carvalho
>> <[email protected]> wrote:
>> > Hello all, sorry for always comming back on the same subject, but
>> tomorrow
>> > is our deadline, and even we got some progress on the osgi front with
>> spring
>> > (we now have services and dependency injection working). Nothing seems to
>> > work on the HttpService integration.
>> >
>> > We tried almost everything to get equinox running inside a servlet
>> > container. The documentation on equinox servlet bridge is almost
>> inexistent.
>> > We are not using their servletbridge since it starts the osgi container
>> and
>> > that is something we are doing in our code (following the sling approach)
>> >
>> > What seems to be happening is that any service tracker registered to
>> > HttpService never gets called, ever... We've seen this on the OsgiManager
>> > class, and now we decided to drop our own little servlet bundle:
>> >
>> > public class Activator implements BundleActivator {
>> >    private ServiceTracker httpServiceTracker;
>> >
>> >    public void start(BundleContext context) throws Exception {
>> >        httpServiceTracker = new HttpServiceTracker(context);
>> >        httpServiceTracker.open();
>> >
>> >    }
>> >
>> >    public void stop(BundleContext arg0) throws Exception {
>> >        httpServiceTracker.close();
>> >        httpServiceTracker = null;
>> >    }
>> >
>> >
>> >    private class HttpServiceTracker extends ServiceTracker {
>> >
>> >        public HttpServiceTracker(BundleContext context) {
>> >            super(context, HttpService.class.getName(), null);
>> >        }
>> >
>> >        public Object addingService(ServiceReference reference) {
>> >            HttpService httpService = (HttpService)
>> > context.getService(reference);
>> >            try {
>> >                httpService.registerServlet("/dummy", new DummyServlet(),
>> > null, null); //$NON-NLS-1$
>> >            } catch (Exception e) {
>> >                e.printStackTrace();
>> >            }
>> >            return httpService;
>> >        }
>> >
>> >        public void removedService(ServiceReference reference, Object
>> > service) {
>> >            HttpService httpService = (HttpService) service;
>> >            httpService.unregister("/dummy"); //$NON-NLS-1$
>> >            super.removedService(reference, service);
>> >        }
>> >    }
>> > }
>> >
>> > Well, the adding servlet never gets called :(
>> >
>> > Here how we start the felix container:
>> >
>> > public void init() throws ServletException {
>> >        ServletContextResourceProvider rp = new
>> > ServletContextResourceProvider(getServletContext());
>> >        Logger logger = new ServletContextLogger(getServletContext());
>> >        Map<Object, Object> props = loadProperties();
>> >        this.osl = new OSL(rp,props,logger);
>> >        this.delegatee = new HttpServiceServlet();
>> >        this.delegatee.init(getServletConfig());
>> >
>> >        super.init();
>> >    }
>> >
>> > public class OSL implements BundleActivator {
>> >
>> >    private Felix felix;
>> >    private ReadWriteLock felixLock;
>> >    private ResourceProvider resourceProvider;
>> >    private Logger logger;
>> >    private BundleActivator httpServiceActivator;
>> >
>> >    public OSL(ResourceProvider rp, Map<Object, Object> props, Logger
>> > logger){
>> >        this.resourceProvider = rp;
>> >        this.logger = logger;
>> >        List<BundleActivator> activators = new
>> ArrayList<BundleActivator>();
>> >        activators.add(this);
>> >        activators.add(new BootstrapInstaller(logger,rp));
>> >        props.put(FelixConstants.SYSTEMBUNDLE_ACTIVATORS_PROP,
>> activators);
>> >        Felix tmpFelix = new Felix(props);
>> >        try {
>> >            tmpFelix.start();
>> >            this.felix = tmpFelix;
>> >        } catch (Exception e) {
>> >            e.printStackTrace();
>> >        }
>> >    }
>> >
>> >    public void start(BundleContext context) throws Exception {
>> >        this.httpServiceActivator = new Activator();
>> >        this.httpServiceActivator.start(context);
>> >
>> >    }
>> >
>> > As you can see, we are starting the Httpservice ourselves, we tried to
>> not
>> > do so and pack it with the other bundles, but the effect is the same (do
>> not
>> > call the addingservice)
>> >
>> > After the complete startup we have these services:
>> >
>> > System Bundle (0) provides:
>> > ---------------------------
>> > org.osgi.service.startlevel.StartLevel
>> > org.osgi.service.packageadmin.PackageAdmin
>> > org.osgi.service.http.HttpService
>> >
>> >
>> > So I guess the HttpService is up and running.
>> >
>> > Is there anything else that we could do? Any other point to look at,
>> replace
>> > class, packaging format, anything please. Tomorrow if we don't present at
>> > least one servlet (we needed at least the GWT-RPC working but one servlet
>> > should do it), we may have to drop osgi for good, and that's something we
>> > are really not willing to do :(
>> >
>> > Regards
>> >
>>
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