报错：Dependency annotations: {@org.springframework.beans.factory.annotation.Autowired(required=true)}

这两天自己搭spingmvc，总是报错，找不到自动注册的bean

Could not autowire field: private lf.service.UserService lf.controllers.UserController.userService; 
nested exception is org.springframework.beans.factory.NoSuchBeanDefinitionException: 
No qualifying bean of type [lf.service.UserService] 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)}

建一个单元测试，看看能不能跑起来，如果能跑起来，说明是web配置错误，如果不能说明类写的有问题。

类检查方面：1.是否在加了@Controller  @Repository @Service 注解

@Controller
@RequestMapping(value = "/user")
public class UserController {

@Service
public class UserServiceImpl implements UserService{

@Repository
public interface UserDao {

2.spring-mvc的配置中 是否自动注册了controller类

<mvc:annotation-driven />
<context:component-scan base-package="lf.controllers"/>

3.spring的配置中，是否注册了用到的类

<context:annotation-config/>
<context:component-scan base-package="lf">
<context:exclude-filter type="annotation" expression="org.springframework.stereotype.Controller"/>
</context:component-scan>

4.如果用了mybatis，看看配置的路径是否正确

<bean id="sqlSessionFactory" class="org.mybatis.spring.SqlSessionFactoryBean">
<property name="dataSource" ref="dataSource"/>
<property name="mapperLocations" value="classpath:mapper/*.xml"/>

<bean class="org.mybatis.spring.mapper.MapperScannerConfigurer">
<property name="basePackage" value="lf.dao"/>
<!--<property name="sqlSessionFactoryBeanName" value="lazySqlSessionFactory"/>-->
</bean>

 
mapper的namespace是否正确

<mapper namespace="lf.dao.UserDao">
<resultMap id="BaseResultMap" type="lf.model.User">
<id property="id" column="id"/>

如果还跑不起来，就可能是web.xml里面丢了listener

<listener>
<listener-class>org.springframework.web.context.ContextLoaderListener</listener-class>
</listener>

我的目录如下