springboot出现错误：No qualifying bean of type ’xxx‘ available

在使用springboot对持久层的方法进行单元测试时，出现错误。

错误一的错误代码如下：

org.springframework.beans.factory.UnsatisfiedDependencyException: 
Error creating bean with name 'cn.tedu.storeExec.StoreExecApplicationTests': 
Unsatisfied dependency expressed through field 'userMapper'; 
nested exception is org.springframework.beans.factory.NoSuchBeanDefinitionException: 
No qualifying bean of type 'cn.tedu.storeExec.mapper.UserMapper' available: 
expected at least 1 bean which qualifies as autowire candidate. 
Dependency annotations: {@org.springframework.beans.factory.annotation.Autowired(required=true)}

Caused by: org.springframework.beans.factory.NoSuchBeanDefinitionException: 
No qualifying bean of type 'cn.tedu.storeExec.mapper.UserMapper' available: 
expected at least 1 bean which qualifies as autowire candidate. 
Dependency annotations: {@org.springframework.beans.factory.annotation.Autowired(required=true)}

上面的错误代码：No qualifying bean of type 'cn.tedu.storeExec.mapper.UserMapper' available，中文意思是说：没有符合的bean可以使用。就是说UserMapper不能被使用。

我的错误原因是没有添加组件扫描而导致的，在springboot的含有main方法的类中添加组件扫描的注解，如下：

添加完成之后，再次启动，进行单元测试，结果成功插入数据到数据库中: