public interface Initable {
   public void init();
}

public class BaseInitable implements Initable {
  public void init() {
    //init code
  }
}

public interface Service extends Initable {
  public Service getService(String name);
}

public class BaseService extends BaseInitable implements Service {
  public Service getService(String name) {
  //return service instance
 }
}
<p>