Autowire

Field userService in com.demo.web.Controller.HomeController required a single bean, but 2 were found:
    - userServiceImpl: defined in file [C:\Users\yangyuping\Desktop\r\maven-projects\web-app\target\classes\com\demo\web\Controller\UserServiceImpl.class]
    - IUserService: defined in file [C:\Users\yangyuping\Desktop\r\maven-projects\web-app\target\classes\com\demo\web\Controller\IUserService.class]

一、指定bean名字为 userServiceImpl
    @Autowired
    private IUserService userServiceImpl;

二、在@Service里指定服务名字

@Service("userService")
public class UserServiceImpl implements IUserService {


@Autowired
private IUserService userService;

Autowire

原文：http://www.cnblogs.com/mr-yang-localhost/p/6705090.html