@Inject field is always null [duplicate]

Answer 1

During the construction of the DataController, it's normal the dataProvider is null. Injection happens after that.

You should add a @PostConstruct method to check for nullity of the field:

@PostConstruct
void init() {
    // dataProvider should not be null here.
}

Aditionally, error reporting on Weld is pretty well done. So you should have an explicit and detailed error message if the injection fails, and not only a null field.