How can access to database in the resource file for API? Edited

[Maxim Olishevsky]

I am creating the plugin.

But I don't have access to BD from Resource files for Api.

I have table model (ModelServiceImpl.java)

@Scanned
@Named
public class ModelServiceImpl implements ModelService {
@ComponentImport
 private final ActiveObjects ao;

 @Inject
 public ModelServiceImpl(ActiveObjects ao)
 {
 this.ao = checkNotNull(ao);
 }
...
}

And Resource file for API(ModelResource.java):

@Path("/endpoint")
public class ModelResource {

    private ModelService modelService;

    public ModelResource(ModelService modelService) {
        this.modelService = modelService;
    }

    @GET
    @Produces({MediaType.APPLICATION_JSON, MediaType.APPLICATION_JSON})
        public Response getModel(@QueryParam("id") int id) {
        CacheControl cacheControl = new CacheControl();
        cacheControl.setNoCache(true);
        return Response.ok(getModelById(id)).cacheControl(cacheControl).build();
    }

   private Model getModelById(int id) {
        return modelService.getById(id); //modelService is null (NullPointerException)
    }
}

How can I access the database in the resource file?

[Alexey Matveev [cPrime] · Accepted solution]

Hello, 

I do not quite understand what the problem is.  Is it NullPointerException in getModelById method? If so then add @Inject to public ModelResource

@Inject
public ModelResource(ModelService modelService) {
        this.modelService = modelService;
    }

[Maxim Olishevsky]

Hello,

Yes, NullPointerException in getModelById method?

I didn't add @Inject.
Thank you very much.