Description: Field ud in com.yjj.service.impl.UserServiceImpl required a bean of type 'com.yjj.dao.UserDao' that could not be found. Action: Consider defining a bean of type 'com.yjj.dao.UserDao'

这是在用springboot时遇到的error

Description:

Field ud in com.yjj.service.impl.UserServiceImpl required a bean of type 'com.yjj.dao.UserDao' that could not be found.

Action:

Consider defining a bean of type 'com.yjj.dao.UserDao' in your configuration.

原因：

我找到的一种原因是在mappers文件夹下的mapper.xml文件没有扫到com.yjj.dao这个包

所以要在Application(启动类)上加上

@MapperScan("com.yjj.dao")注解

代码如下：

package com.yjj.bootdemo01;

import org.mybatis.spring.annotation.MapperScan;
import org.springframework.boot.SpringApplication;
import org.springframework.boot.autoconfigure.SpringBootApplication;
import org.springframework.context.annotation.ComponentScan;

@SpringBootApplication
@ComponentScan(basePackages = {"com.yjj.dao","com.yjj.service","com.yjj.controller"})
@MapperScan("com.yjj.dao")
public class Bootdemo01Application {

    public static void main(String[] args) {
        SpringApplication.run(Bootdemo01Application.class, args);
    }

}