Spring异常: {@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。

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

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4000

@Controller  

@RequestMapping(value = "/user")  

public class UserController {  

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@Service  

public class UserServiceImpl implements UserService{  

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@Repository  

public interface UserDao {  

2.spring-mvc的配置中 是否自动注册了controller类

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<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

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<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

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<bean id="sqlSessionFactory" class="org.mybatis.spring.SqlSessionFactoryBean">  

    <property name="dataSource" ref="dataSource"/>  

    <property name="mapperLocations" value="classpath:mapper/*.xml"/>  

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<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

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<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

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<listener>  

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

</listener>  

我的目录如下