As seen in the following example, instead of relying on the Classloading of the Neo4j kernel, the Neo4j bundles are treated as library bundles, and services like the IndexProviders and CacheProviders are explicitly instantiated, configured and registered. Just make the necessary jars available as wrapped library bundles, so all needed classes are exported and seen by the bundle containing the Activator.

public class Neo4jActivator implements BundleActivator
{

    private static GraphDatabaseService db;
    private ServiceRegistration serviceRegistration;
    private ServiceRegistration indexServiceRegistration;

    @Override
    public void start( BundleContext context ) throws Exception
    {
        //the cache providers
        ArrayList<CacheProvider> cacheList = new ArrayList<CacheProvider>();
        cacheList.add( new SoftCacheProvider() );

        //the index providers
        IndexProvider lucene = new LuceneIndexProvider();
        ArrayList<IndexProvider> provs = new ArrayList<IndexProvider>();
        provs.add( lucene );
        ListIndexIterable providers = new ListIndexIterable();
        providers.setIndexProviders( provs );

        //the database setup
        GraphDatabaseFactory gdbf = new GraphDatabaseFactory();
        gdbf.setIndexProviders( providers );
        gdbf.setCacheProviders( cacheList );
        db = gdbf.newEmbeddedDatabase( "target/db" );

        //the OSGi registration
        serviceRegistration = context.registerService(
                GraphDatabaseService.class.getName(), db, new Hashtable<String,String>() );
        System.out.println( "registered " + serviceRegistration.getReference() );
        indexServiceRegistration = context.registerService(
                Index.class.getName(), db.index().forNodes( "nodes" ),
                new Hashtable<String,String>() );
        Transaction tx = db.beginTx();
        try
        {
            Node firstNode = db.createNode();
            Node secondNode = db.createNode();
            Relationship relationship = firstNode.createRelationshipTo(
                    secondNode, DynamicRelationshipType.withName( "KNOWS" ) );

            firstNode.setProperty( "message", "Hello, " );
            secondNode.setProperty( "message", "world!" );
            relationship.setProperty( "message", "brave Neo4j " );
            db.index().forNodes( "nodes" ).add( firstNode, "message", "Hello" );
            tx.success();
        }
        catch ( Exception e )
        {
            e.printStackTrace();
            throw new RuntimeException( e );
        }
        finally
        {
            tx.finish();
        }

    }

    @Override
    public void stop( BundleContext context ) throws Exception
    {
        serviceRegistration.unregister();
        indexServiceRegistration.unregister();
        db.shutdown();

    }

}

	Tip
	The source code of the example above is found here.