Field required a bean of type that could not be found.' - spring-boot

Question

The structure has no problem. The spring-boot can scan UserMapper but can't scan UserService. I tried to give my UserService #Mapper component, then it could be scanned. But I don't know how to use other methods to let it be scanned. I tried #Service but it doesn't work.
package com.mywebprojet.springboot;
import org.springframework.boot.SpringApplication;
import org.springframework.boot.autoconfigure.SpringBootApplication;
#SpringBootApplication
public class MywebprojectApplication {
public static void main(String[] args) {
SpringApplication.run(MywebprojectApplication.class, args);
}
}
package com.mywebprojet.springboot.controller;
import java.util.List;
import org.springframework.beans.factory.annotation.Autowired;
import org.springframework.stereotype.Controller;
import org.springframework.ui.Model;
import org.springframework.web.bind.annotation.RequestMapping;
import org.springframework.web.bind.annotation.RequestMethod;
import org.springframework.web.bind.annotation.RestController;
import com.mywebprojet.springboot.entity.User;
import com.mywebprojet.springboot.mapper.UserMapper;
import com.mywebprojet.springboot.service.UserService;
#RestController
#RequestMapping(value = "user")
public class UserController {
#Autowired
private UserMapper userMapper;
#Autowired
private UserService userService;
}
package com.mywebprojet.springboot.service;
import java.util.List;
import org.springframework.stereotype.Service;
import com.mywebprojet.springboot.entity.User;
#Service
public interface UserService{
void insert(User user);
}

Answer 1

You should write a UserService Implementation and have it annotated with #Service, not the interface. For example:
#Service
public class UserServiceImpl implements UserService {
#Override
public void insert(User user) {
// Implementation
}
}