OSGi bridge for hybrid Java EE app

OSGiBridge.java

import java.util.Collection;
import java.util.Properties;
import org.osgi.framework.Bundle;
import org.osgi.framework.BundleListener;
import org.osgi.framework.ServiceListener;
import org.osgi.framework.ServiceReference;
import org.osgi.framework.ServiceRegistration;

public interface OSGiBridge {

    boolean registerBundleListener(BundleListener listener);

    boolean registerServiceListener(ServiceListener listener);

    <C, S extends C> ServiceRegistration registerService(
            Class<C>[] contracts, S service, Properties properties);
    
    <C, S extends C> ServiceRegistration registerService(
            Class<C> contract, S service, Properties properties);

    ServiceReference getServiceReference(Class<?> contract);

    Collection<ServiceReference> getServiceReferences(Class<?> contract, String filter);

    Object getService(ServiceReference ref);

    void ungetService(ServiceReference ref);

    Collection<Bundle> getBundles();

}