Please read your error messages more carefully. You have an autowiring problem:
NoSuchBeanDefinitionException: No qualifying bean of type **'com.mthree.service.UserService'** available: expected at least 1 bean which qualifies as autowire candidate. Dependency annotations: {@org.springframework.beans.factory.annotation.Autowired(required=true)}
You should add an annotation to tell Spring that your bean is under its control:
@Service(value = "userService")
public class UserServiceImpl implements UserService{
solved Spring MVC, Maven, CRUD, MongoDB [closed]