Consider defining a bean of type 'app.mapper.UserMapper' in your configuration.

bug具体内容：

Description: Parameter 0 of constructor in app.controller.IndexControllerMaYi required a bean of type 'app.mapper.UserMapper' that could not be found. Action: Consider defining a bean of type 'app.mapper.UserMapper' in your configuration.

解决方法

在main方法中加入

@MapperScan({"app.mapper","app.test01.dao","app.test02.dao"})

//我的程序******* package app; import org.mybatis.spring.annotation.MapperScan; import org.springframework.boot.SpringApplication; import org.springframework.boot.autoconfigure.SpringBootApplication; import org.springframework.context.annotation.ComponentScan; @ComponentScan(basePackages = "app") @MapperScan({"app.mapper","app.test01.dao","app.test02.dao"}) @SpringBootApplication //开启组件扫描和自动配置 public class BooklistApplication {//不只是启动引导类，还是配置类 public static void main(String[] args) { SpringApplication.run(BooklistApplication.class, args);//负责启动引导应用程序 System.out.println("main..."); } }

总结：

@SpringBootApplicatoin=@Configuration+@EnableAutoConfiguration+@ComponentScan

@SpringBootApplicatoin是用的@ComponentScan扫描的，扫描的是Component，包括@Component, @Controller, @Service, @Repository等

在对Mybatis自动扫描配置中，使用注解配置时，我们只要在@MapperScan中配置我们需要扫描的Mapper位置，大部分情况下是满足需求的。