Handling Exceptions

The OSGi interface BundleActivator is defined as:

   public interface BundleActivator {
     public void start(BundleContext context) throws Exception;
     public void stop(BundleContext context) throws Exception;
   }

The BaseBundleActivator class defined by SAT implements this interface and provides final implementations of the start(BundleContext) and stop(BundleContext) methods.

If an exception occurs while starting or stopping a bundle, SAT catches the exception and sends the bundle activator the handler hook method handleException(Exception) that is implemented by the BaseBundleActivator class as follows:

   protected boolean handleException(Exception exception) {
     return false;
   }

The BaseBundleActivator implementation of the handleException(Exception) method simply returns false, indicating that the exception was not fully handled and needs to be thrown by SAT. If the exception is not fully handled the exception will be re-thrown by the BaseBundleActivator.
Bundles that wish to attempt to fully handle thrown exceptions should override the hook handler method handleException(Exception), returning true to prevent the exception being re-thrown by SAT.
Remember, a bundle that throws an execution while executing the start(BundleContext) method will roll-back to the Resolved state. Catching a thrown exception might mean that the bundle can successfully transition to the Active state.