How to create a RESTful API with Jersey + Grizzly + Guice + Hibernate

Question

I've spent some time trying to create a RESTful API with Jersey, Grizzly, Guice and Hibernate, and I'm having a very difficult time wrapping my head around how to wire everything together. This is what I've been able to figure out on my own.

• I have a working DAO that implements a simple interface. I'm using Guice to inject here. I used this post as a reference.

   public class ProjectDAO implements ProjectDAOGeneric {
       private final Provider<EntityManager> entityManagerProvider;
  
       @Inject
       public ProjectDAO(Provider<EntityManager> entityManagerProvider) {
         this.entityManagerProvider = entityManagerProvider;
       }
  
       @Transactional
       public void insert(Project project) {
         entityManagerProvider.get().persist(project);
       }
  
   // (...)     
  

---

• I created a very simple CRUD API with Jersey. I used this course I found on PluralSight for help.

   @Path("/project")
   public class ProjectResource {
  
       private final ProjectDAOGeneric projectDAO;
  
       @Inject
       public ProjectResource(ProjectDAOGeneric projectDAO) {
         this.projectDAO = projectDAO;
       }
  
       @GET
       @Produces(MediaType.APPLICATION_JSON)
       public List<Project> getProjects() {
         return projectDAO.findAll();
       }
  
   // (...)
  

---

• From what I understand, I have to bridge Guice and HK2 so that both of them work together. I have something like this.

  public class HK2toGuiceModule extends AbstractBinder {
  
    private Injector guiceInjector;
  
    public HK2toGuiceModule(Injector guiceInjector) {
      this.guiceInjector = guiceInjector;
    }
  
    @Override
    protected void configure() {
      bindFactory(new ServiceFactory<ProjectService>(guiceInjector, ProjectService.class)).to(ProjectService.class);
    }
  
    private static class ServiceFactory<T> implements Factory<T> {
      private final Injector guiceInjector;
      private final Class<T> serviceClass;
  
      public ServiceFactory(Injector guiceInjector, Class<T> serviceClass) {
        this.guiceInjector = guiceInjector;
        this.serviceClass = serviceClass;
      }
  
      @Override
      public T provide() {
        return guiceInjector.getInstance(serviceClass);
      }
  
      @Override
      public void dispose(T versionResource) {
      }
  
  }
  

---

• After that, I can create a simple Guice Module to bind the ProjectDAO interface to its implementation.

  public class GuiceModule extends AbstractModule {
    @Override
    protected void configure() {
      bind(ProjectDAOGeneric.class).to(ProjectDAO.class);
    }
  }
  

---

• I imagine that we would then need to create a ResourceConfig to initialize Grizzly, also taking the Guice bridge into consideration. I have something like this.

@ApplicationPath("/")
public class Config extends ResourceConfig {

  @Inject
  public Config(ServiceLocator serviceLocator) {
    packages("com.myproject");
    Injector injector = Guice.createInjector(new GuiceModule());
    initGuiceIntoHK2Bridge(serviceLocator, injector);
  }

  private void initGuiceIntoHK2Bridge(ServiceLocator serviceLocator, Injector injector) {
    GuiceBridge.getGuiceBridge().initializeGuiceBridge(serviceLocator);
    GuiceIntoHK2Bridge guiceBridge = serviceLocator.getService(GuiceIntoHK2Bridge.class);
    guiceBridge.bridgeGuiceInjector(injector);
  }

}

---

• I figure that the last step would be to use that ResourceConfig in order to initialize the Grizzly HttpServer.

public class Main {

    public static final String BASE_URI = "http://localhost:8080/";

    public static HttpServer startServer() {
        final ResourceConfig config = new ResourceConfig().packages("com.myproject");
        return GrizzlyHttpServerFactory.createHttpServer(URI.create(BASE_URI), config);
    }

    public static void main(String[] args) throws InterruptedException, IOException {

      // (...)

Now, I can't figure out how to do this. The only code I have here is the one that Grizzly provides by default. I'm not sure how to use the custom ResourceConfig I created.

---

Most of what I found online was +5 years old, and the most relevant post on StackOverflow asking about this topic is 12 years old at this point. So I figured that either Google is not being very helpful or I'm missing something. I can't seem to figure it out on my own, and I definitely haven't been able to find any up-to-date resources about it.

With all this, I have two simple questions:

• Does my current approach even make sense?
• If it does, how can I connect everything together? What am I missing?

Thanks a lot