SpringBoot启动失败，Bean配置失败

原因：在mybatis-spring-boot-autoconfigure的jar包中有一个类 MybatisAutoConfiguration，在这个类中的registerBeanDefinitions方法告诉了我们

@Override

    public void registerBeanDefinitions(AnnotationMetadata importingClassMetadata, BeanDefinitionRegistry registry) {

      logger.debug("Searching for mappers annotated with @Mapper");

      ClassPathMapperScanner scanner = new ClassPathMapperScanner(registry);

      try {

        if (this.resourceLoader != null) {

          scanner.setResourceLoader(this.resourceLoader);

        }

        List<String> packages = AutoConfigurationPackages.get(this.beanFactory);

        if (logger.isDebugEnabled()) {

          for (String pkg : packages) {

            logger.debug("Using auto-configuration base package '{}'", pkg);

          }

        }

        scanner.setAnnotationClass(Mapper.class);

        scanner.registerFilters();

        scanner.doScan(StringUtils.toStringArray(packages));

      } catch (IllegalStateException ex) {

        logger.debug("Could not determine auto-configuration package, automatic mapper scanning disabled.", ex);

      }

    }

解决方案

1、mapper(Dao层)

添加 @Mapper

2、在启动类

@MapperScan(value = "com.xxxxx.dao")

SpringBootApplication
@MapperScan(value = "com.ptteng.academy.Mapper")
public class HomeWebApplication {
    public static void main(String[] args) {
        SpringApplication.run(HomeWebApplication.class, args);
    }
}