In which classes is it allowed to use @Autowired in a Spring Boot application?

Question

The following code snippet works in a Spring Boot 1.5.7 application.

@Controller
public class MainController {

    @Autowired
    private EventtypeRepository eventtypeRepository;

    private BetfairFacade client = new BetfairFacade();

    @GetMapping(path="/update")
    public @ResponseBody int updateBetfair() {
        return client.updateBetfair(eventtypeRepository);
    }

}



public class BetfairFacade {

public BetfairFacade() {
}

public int updateBetfair(EventtypeRepository eventtypeRepository) {
    int out = 0;

    Eventtype bfT = new Eventtype();
    bfT.setEventtype("foo");
    bfT.setName("bar");
    eventtypeRepository.save(bfT);

    return out;
    }

}

The following snippet does NOT work because when I try to instantiate eventtypeRepository in BetfairFacade the field remains null.

@Controller
public class MainController {

    private BetfairFacade client = new BetfairFacade();

    @GetMapping(path="/update")
    public @ResponseBody int updateBetfair() {
        return client.updateBetfair();
    }

}



@Component
public class BetfairFacade {

   @Autowired
   public EventtypeRepository eventtypeRepository;


   public BetfairFacade() {
   }

   public int updateBetfair() {
     int out = 0;

     Eventtype bfT = new Eventtype();
     bfT.setEventtype("foo");
     bfT.setName("bar");
     eventtypeRepository.save(bfT);

     return out;
   }

}

Why does not this work? Is it possible to get this working, if so how?

I actually read that question plus its answers but did not help me as much as the very precise custom answer I received here. — nilo de roock, Sep 21 '17 at 12:22

score 3 · Accepted Answer · answered Sep 21 '17 at 10:59

3

You have to @Autowire the BetfairFacade in order for the repository injection to work. If you instantiate manually like you did, spring will not treat that as a managed bean.

@Controller
public class MainController {

    @Autowire
    private BetfairFacade client;

answered Sep 21 '17 at 10:59

Maciej Kowalski

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That is what I did in both examples, so this answer does not really help. – nilo de roock Sep 21 '17 at 11:01
Betfairfacade is not a repository class, are you sure? – nilo de roock Sep 21 '17 at 11:03
No, `BetfairFacade` is createdy by `new`, not injected by Spring. When creating by `new` it's just regular object instantiation, and Spring has nothing to do with it, so all it's annotations inside are ignored. – amorfis Sep 21 '17 at 11:03
2

Actually, what you did in the second example was: `private BetfairFacade client = new BetfairFacade()` and what @Maciej Kowalski proposes is to change it to `@Autowire private BetfairFacade client;` – Alberto S. Sep 21 '17 at 11:04
OK. Got that, will try. – nilo de roock Sep 21 '17 at 11:08
That worked. Thanks guys. – nilo de roock Sep 21 '17 at 11:15

In which classes is it allowed to use @Autowired in a Spring Boot application?

1 Answers1