소나 버그 잡기

Use constructor injection for this field

@Inject private XXXService xxxService;

why? http://olivergierke.de/2013/11/why-field-injection-is-evil/

Or Inject -> Autowired ( Autowired 와 Inject 차이 - http://dev-eido.tistory.com/entry/Autowired-Resource-Inject%EC%9D%98-%EC%B0%A8%EC%9D%B4 )