Field userService in com.wuji.controller.UserController required a bean of type 'com.wuji.service.UserService' that could not be found

Field userService in com.wuji.controller.UserController required a bean of type 'com.wuji.service.UserService' that could not be found.

原因：说明IOC里没有创建Bean，在启动文件上手动添加：@ComponentScan(basePackages = {"com.wuji"})注解开启Spring组件扫描