Unsatisfied dependency expressed through field ‘userMapper‘问题解决

SSM框架练手，mapper层@Autowire创建bean怎么也不成功，报错：

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

搞了一天，终于发现有两处错误：

web.xml文件中缺少一段代码

 org.springframework.web.context.ContextLoaderListener 

这一段代码的功能是注册Spring框架，启动spring容器，我的理解是spring容器没有启动成功，所以注解@Autowire出错了

还有就是，在applicationContext_service.xml文件中 ，该段代码

其中ref="dataResources"  写成了value="dataResources"，一不小心就错了

改了这两处之后，错误消失了