错误信息：
Field userService in com.lncywlc.rio.controller.LoginController required a bean of type ‘com.lncywlc.rio.service.UserService’ that could not be found.
The injection point has the following annotations:
- @org.springframework.beans.factory.annotation.Autowired(required=true)
Action:
Consider defining a bean of type ‘com.lncywlc.rio.service.UserService’ in your configuration.
这个问题主要是马虎大意造成的。
一定要在实现类中声明服务 @Service
当然了，如果你的问题并不是忘记声明服务，可以将
@Autowired 改成 @Resource 试一试