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• 出现下方错误请查看启动类：XXXApplication 是否扫描到mapper映射文件，声明eclipse和idea不一样，这里eclipse可以跑通，idea中不行

        ***************************
        APPLICATION FAILED TO START
        ***************************

        Description:

        Field chapterDao in cn.yixue.service.ChapterServiceImp required a bean of type 'cn.yixue.dao.ChapterMapper' that could not be found.

        The injection point has the following annotations:
            - @org.springframework.beans.factory.annotation.Autowired(required=true)


        Action:

        Consider defining a bean of type 'cn.yixue.dao.ChapterMapper' in your configuration.


        以上提取出有用的信息：required a bean of type 'xxxx' that could not be found.
        
        代表bean没注入，从bean注入寻找方向，有的人会说我用@Autowired之类的种种，但没扫到，好吧~

解决方法：

1. 在相应的mapper类中加@Mapper标注让springboot根据标注去将mapper注入

@Mapper
public interface ChapterMapper {
    ......
}

1. 启动类加@MapperScan(value = "cn.yixue.video.dao") value 后的包一定要对应到mapper类对应的地方，比如我的mapper在dao下，就是cn.yixue.video.dao

@SpringBootApplication
@MapperScan(value = "cn.yixue.video.dao")
@EnableDiscoveryClient
public class YixueVideoApplication {

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

}

以下大佬给我很大的启发，灰常感谢

https://www.cnblogs.com/cxylff/p/10969375.html