Consider defining a bean of type ‘com.wei.service.UserService‘ in your configuration

一般都是注解出错，在

service

的实现类中加入

@Service(value = "userService")

就行；

如果还不行，就看看下面我写的三层代码吧！


特别注意：注解的位置

，是否添加了注解

还有，我在

serviceImpl

中加入了注解

Autowired

之后变量变红，但是运行没错，我觉得应该是编译软件的问题吧！个人感觉


mapper


package com.wei.mapper;

import com.wei.pojo.User;
import org.apache.ibatis.annotations.Mapper;
import org.springframework.stereotype.Component;
import org.springframework.stereotype.Repository;

import java.util.List;

// 表明这是一个mybatis的mapper类；
@Mapper
@Repository  // 表示dao层， 也可以用 @Component万能，所有层都可以用
public interface UserMapper {

    List<User> queryUserList();

    User queryUserById(int id);

    int addUser(User user);

    int deleteUser(int id);

    int updateUser(User user);


}


service

:

package com.wei.service;

import com.wei.pojo.User;
import org.springframework.boot.autoconfigure.SpringBootApplication;
import org.springframework.context.annotation.ComponentScan;
import java.util.List;

@SpringBootApplication

public interface UserService {
    List<User> queryUserList();

    User queryUserById(int id);

    int addUser(User user);

    int deleteUser(int id);

    int updateUser(User user);
}


service

实现类：

package com.wei.service;

import com.wei.mapper.UserMapper;
import com.wei.pojo.User;
import org.springframework.beans.factory.annotation.Autowired;
import org.springframework.stereotype.Service;

import java.util.List;
@Service(value = "userService")
public class UserServiceImpl implements UserService{

    @Autowired
    private UserMapper userMapper;
    public void setUserMapper(UserMapper userMapper){
        this.userMapper=userMapper;
    }
    @Override
    public List<User> queryUserList() {
        return userMapper.queryUserList();
    }

    @Override
    public User queryUserById(int id) {
        return userMapper.queryUserById(id);
    }

    @Override
    public int addUser(User user) {
        return userMapper.addUser(user);
    }

    @Override
    public int deleteUser(int id) {
        return userMapper.deleteUser(id);
    }

    @Override
    public int updateUser(User user) {
        return updateUser(user);
    }
}


controller

：

package com.wei.controller;

import com.wei.pojo.User;
import com.wei.service.UserService;
import org.mybatis.spring.annotation.MapperScan;
import org.springframework.beans.factory.annotation.Autowired;

import org.springframework.beans.factory.annotation.Qualifier;
import org.springframework.web.bind.annotation.RequestMapping;
import org.springframework.web.bind.annotation.RestController;

import java.util.List;

@RestController
public class userController {

    @Autowired
    public UserService userService;

    @RequestMapping("/queryUserList")
    public List<User> queryUserList(){
        List<User> userList = userService.queryUserList();
        for (User user : userList) {
            System.out.println(user);
        }
        return userList;
    }

}

后面因为自己的强迫症，实在忍不了了，就在网上查了解决方法，具体看图，取消该选择就行：