spring+mybatis使用注解形式出现注入失败可能原因

出现类似以下错误：

严重: Exception sending context initialized event to listener instance of class org.springframework.web.context.ContextLoaderListener
org.springframework.beans.factory.BeanCreationException: Error creating bean with name 'userServiceImpl': Injection of autowired dependencies failed; nested exception is org.springframework.beans.factory.BeanCreationException: Could not autowire field: private cn.springmvc.dao.UserDAO cn.springmvc.service.impl.UserServiceImpl.userDAO; nested exception is org.springframework.beans.factory.NoSuchBeanDefinitionException: No qualifying bean of type [cn.springmvc.dao.UserDAO] found for dependency: expected at least 1 bean which qualifies as autowire candidate for this dependency. Dependency annotations: {@org.springframework.beans.factory.annotation.Autowired(required=true)}
at org.springframework.beans.factory.annotation.AutowiredAnnotationBeanPostProcessor.postProcessPropertyValues(AutowiredAnnotationBeanPostProcessor.java:288)
at org.springframework.beans.factory.support.AbstractAutowireCapableBeanFactory.populateBean(AbstractAutowireCapableBeanFactory.java:1116)

at org.springframework.beans.factory.support.AbstractAutowireCapableBeanFactory.doCreateBean(AbstractAutowireCapableBeanFactory.java:519)

可能原因：

1、是否在dao、service、controller分别加注解

@Repository

@Service("xxxService")

@Controller("xxxController")
以及
@Resource(name = "xxxService")
private XxxService xxxService;

2、在spring配置文件中是否配置以下组件

<!-- 开启注解处理器 -->
<context:annotation-config/>

<!-- 启用spring mvc 注解, 默认的注解映射的支持 -->
<mvc:annotation-driven/>
<context:component-scan base-package="com.xxx.xxx.dao,com.xxx.xxx.service,com.xxx.xxx.controller">
</context:component-scan>

3、检查web.xml文件是否加载spring和mybatis配置文件

4、检查注解名是否一致

5、检查spring配置文件扫描mapper与dao接口是否配置正确

这些细节可能会忽视，虽然都是平常开发常见的配置，但是若是漏掉了，会发生错误，一时想不到这些