Field studentsMapper in site.longkui.app.service.StudentsService required a bean of type ‘site.longkui.app.mapper.StudentsMapper’ that could not be found.

原文链接：Field studentsMapper in site.longkui.app.service.StudentsService required a bean of type ‘site.longkui.app.mapper.StudentsMapper’ that could not be found. – 每天进步一点点

 

某日新创建spring boot项目后启动项目报错：

Description:

Field studentsMapper in site.longkui.app.service.StudentsService required a bean of type 'site.longkui.app.mapper.StudentsMapper' 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 'site.longkui.app.mapper.StudentsMapper' in your configuration.

这个错误是因为我们没有加上MapperScan注解。

我们找到启动类，在前面加上@MapperScan注解，并加入需要扫描是包路径。比如下面这样：

@SpringBootApplication
@MapperScan("site.longkui.**.mapper")
public class AppApplication {

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

}

其中，**表示模糊匹配，方便后期项目进行扩展。然后重新启动项目就正常了。