Re: Newbie question for ClassCastException

> I'm sure I am presently asking a really simple question that have been seen
> a thousand times.  But since I don't know where to start with OSGI, I'll ask
> the question here in hope that one person would help me.
>
> We need to build a plugin management for a web application running wicket.
> It is already running and I would want to include OSGI bundle
> extendability.  I want bundles that are added to register as services in
> order to give access to some methods.  The bundle is installed in felix
> using the FileInstall activator.  I will not paste all the code since I
> think the interface and implementation is irrelevant here. (Even if they are
> really simple).  The problem come with the fact that I cannot cast the
> service received into the interface implemented.  I get a ClassCastException
> when trying to use it.
>
> Here is the code at initialization of the web application :
> //Make the felix startup here.
>          Properties felixProps = new Properties();
>          try {
>
> felixProps.load(this.getClass().getResourceAsStream("/felix.properties"));
>          } catch(Exception e) {
>              logger.warn("Could not load felix properties", e);
>          }
>
>          List<BundleActivator>  list = new ArrayList<BundleActivator>();
>
>          FileInstall activator = new FileInstall();
>          list.add(activator);
>
>          this.panelProvider = new PanelServiceProvider();
>          list.add(this.panelProvider);
>
>          felixProps.put(FelixConstants.SYSTEMBUNDLE_ACTIVATORS_PROP, list);
>          try {
>              this.felix = new Felix(felixProps);
>              this.felix.start();
>              logger.info("Felix started.");
>          } catch(Exception ex) {
>              logger.error("Could not load felix", ex);
>          }
>
> Here is the code for the PanelServiceProvider class :
> public class PanelServiceProvider implements BundleActivator {
>
>      private ServiceTracker serviceTracker;
>      public void start(BundleContext context) throws Exception {
>          this.serviceTracker = new ServiceTracker(context,
> PanelDescriptor.class.getName(), null);
>          this.serviceTracker.open();
>      }
>      public void stop(BundleContext arg0) throws Exception {
>          this.serviceTracker.close();
>      }
>
>      public List<PanelDescriptor>  getAllPanelDescriptor(){
>          if(this.serviceTracker != null){
>              Object[] services = this.serviceTracker.getServices();
>              if(services != null){
>                  List<PanelDescriptor>  panels = new
> ArrayList<PanelDescriptor>(services.length);
>                  for(Object service : services){
>                      if(service instanceof PanelDescriptor){
>                          panels.add((PanelDescriptor)service);
>                      }else{
>                          System.out.println("Unknown service : " +
> service.getClass().getName());
>                          for(Type type :
> service.getClass().getGenericInterfaces()){
>                              System.out.println("Implementing : " +
> type.toString());
>                          }
>                      }
>                  }
>                  return panels;
>              }
>          }
>          return null;
>      }
> }
>
> And here is the result that I get for invoking this method when I call the
> page in the web app :
>
> Installed
> c:\java\project\demo-wicket-felix\target\felix\fileinstall\panel1-0.0.1-SNAPSHOT.jar
> 2009-06-18 10:18:34.544::INFO:  Started SelectChannelConnector@...:8080
> [INFO] Started Jetty Server
> Unknown service : com.mycompany.panel.PanelDescriptorImpl
> Implementing : interface com.mycompany.panel.PanelDescriptor
>
>
> What that mean is that the serive is loaded, it can be reached, but the
> classes does not come from the same classloader.  Now, I'm a little lost as
> to what I'm supposed to do in this case.Does anybody have an idea on what I
> could do to solve this problem?
>
> If more details is needed (Like the manifest files or the other classes),
> let met know and I'll provide them.
>
> Thanks in advance.
>
> Marc-Andre
>
>