Spring Autowiring Service在我的控制器中不起作用
问题内容:
我在自动连接控制器中的服务时遇到问题。我有这个错误:
org.springframework.beans.factory.BeanCreationException: Error creating bean with name 'myController': Injection of autowired dependencies failed; nested exception is org.springframework.beans.factory.BeanCreationException: Could not autowire field: private es.unican.meteo.service.UserService es.unican.meteo.controller.MyController.userService; nested exception is org.springframework.beans.factory.NoSuchBeanDefinitionException: No matching bean of type [es.unican.meteo.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)}
似乎未注册userService,因此,控制器无法获取Bean。我认为我的配置还可以,因为它可以与测试一起使用。在测试中我有这个:
ClassPathXmlApplicationContext("/WEB-INF/app-config.xml");
我可以从ApplicationContext.xml中获取Bean
我的程序包结构如下:
es.unican.meteo.controller
| ---- MyController.java
es.unican.meteo.service
| ---- UserService.java
es.unican.meteo.service.impl
| ---- UserServiceImpl.java
.....
网站内容/ WEB-INF
| ---- MyDispatcherServlet-servlet.xml
| ---- app-config.xml
| ---- web.xml
.....
的分类:
== UserServiceImpl.java ==
@Service
public class UserServiceImpl implements UserService{
@Autowired
private UserMapper userMapper;
public void setUserMapper(UserMapper userMapper) {
this.userMapper = userMapper;
}
== MyController.java ==
@Controller
public class MyController {
@Autowired
private UserService userService;
@RequestMapping(method=RequestMethod.GET, value="/home")
public String handleRequest(){
return "welcome";
}
@RequestMapping(method=RequestMethod.GET, value="/getUsers")
public @ResponseBody List<User> getUsersInJSON(){
return userService.getUsers();
}
}
== web.xml ==
<display-name>Spring MVC</display-name>
<servlet>
<servlet-name>MyDispatcherServlet</servlet-name>
<servlet-class>org.springframework.web.servlet.DispatcherServlet</servlet-class>
</servlet>
<servlet-mapping>
<servlet-name>MyDispatcherServlet</servlet-name>
<url-pattern>*.go</url-pattern>
</servlet-mapping>
</web-app>
== app-config.xml ===
<?xml version="1.0" encoding="UTF-8"?>
<beans xmlns="http://www.springframework.org/schema/beans"
xmlns:xsi="http://www.w3.org/2001/XMLSchema-instance"
xmlns:context="http://www.springframework.org/schema/context"
xmlns:p="http://www.springframework.org/schema/p"
xmlns:mvc="http://www.springframework.org/schema/mvc"
xsi:schemaLocation="http://www.springframework.org/schema/beans http://www.springframework.org/schema/beans/spring-beans-3.1.xsd
http://www.springframework.org/schema/context http://www.springframework.org/schema/context/spring-context-3.1.xsd
http://www.springframework.org/schema/mvc http://www.springframework.org/schema/mvc/spring-mvc-3.1.xsd">
<!-- Scans the classpath of this application for @Components to deploy as beans -->
<context:component-scan base-package="es.unican.meteo" />
<!-- Configures the @Controller programming model -->
<mvc:annotation-driven/>
<bean id="dataSource" class="org.springframework.jdbc.datasource.DriverManagerDataSource"
p:driverClassName="org.apache.derby.jdbc.EmbeddedDriver"
p:url="jdbc:derby:C:\tools\derbydb"
p:connectionProperties=""
p:username="APP"
p:password="" />
<bean id="transactionManager" class="org.springframework.jdbc.datasource.DataSourceTransactionManager">
<property name="dataSource" ref="dataSource"/>
</bean>
<bean id="sqlSessionFactory" class="org.mybatis.spring.SqlSessionFactoryBean">
<property name="dataSource" ref="dataSource" />
<property name="configLocation" value="/mybatis-config.xml" />
</bean>
<bean id="usersMapper" class="org.mybatis.spring.mapper.MapperFactoryBean">
<property name="mapperInterface" value="es.unican.meteo.dao.UserMapper" />
<property name="sqlSessionFactory" ref="sqlSessionFactory" />
</bean>
<bean id="rolesMapper" class="org.mybatis.spring.mapper.MapperFactoryBean">
<property name="mapperInterface" value="es.unican.meteo.dao.RoleMapper" />
<property name="sqlSessionFactory" ref="sqlSessionFactory" />
</bean>
</beans>
== MyDispatcherServlet.xml ==
<?xml version="1.0" encoding="UTF-8"?>
<beans xmlns="http://www.springframework.org/schema/beans"
xmlns:xsi="http://www.w3.org/2001/XMLSchema-instance"
xmlns:context="http://www.springframework.org/schema/context"
xmlns:mvc="http://www.springframework.org/schema/mvc"
xsi:schemaLocation="http://www.springframework.org/schema/beans http://www.springframework.org/schema/beans/spring-beans.xsd
http://www.springframework.org/schema/context http://www.springframework.org/schema/context/spring-context-3.1.xsd
http://www.springframework.org/schema/mvc http://www.springframework.org/schema/mvc/spring-mvc-3.1.xsd">
<!-- Enabling Spring beans auto-discovery -->
<context:component-scan base-package="es.unican.meteo.controller" />
<!-- Enabling Spring MVC configuration through annotations -->
<mvc:annotation-driven />
<!-- Defining which view resolver to use -->
<bean class= "org.springframework.web.servlet.view.InternalResourceViewResolver" >
<property name="prefix" value="/WEB-INF/views/" />
<property name="suffix" value=".jsp" />
</bean>
Spring MVC记录器跟踪:
19:38:54,119 DEBUG http-8080-1 support.DefaultListableBeanFactory:430 - Creating instance of bean 'myController'
19:38:54,170 DEBUG http-8080-1 annotation.InjectionMetadata:60 - Found injected element on class [es.unican.meteo.controller.MyController]: AutowiredFieldElement for private es.unican.meteo.service.UserService es.unican.meteo.controller.MyController.userService
19:38:54,174 DEBUG http-8080-1 support.DefaultListableBeanFactory:504 - Eagerly caching bean 'myController' to allow for resolving potential circular references
19:38:54,206 DEBUG http-8080-1 annotation.InjectionMetadata:85 - Processing injected method of bean 'myController': AutowiredFieldElement for private es.unican.meteo.service.UserService es.unican.meteo.controller.MyController.userService
19:38:54,224 DEBUG http-8080-1 support.DefaultListableBeanFactory:217 - Creating shared instance of singleton bean 'userServiceImpl'
19:38:54,226 DEBUG http-8080-1 support.DefaultListableBeanFactory:430 - Creating instance of bean 'userServiceImpl'
19:38:54,234 DEBUG http-8080-1 annotation.InjectionMetadata:60 - Found injected element on class [es.unican.meteo.service.impl.UserServiceImpl]: AutowiredFieldElement for private es.unican.meteo.dao.UserMapper es.unican.meteo.service.impl.UserServiceImpl.userMapper
19:38:54,237 DEBUG http-8080-1 support.DefaultListableBeanFactory:504 - Eagerly caching bean 'userServiceImpl' to allow for resolving potential circular references
19:38:54,256 DEBUG http-8080-1 annotation.InjectionMetadata:85 - Processing injected method of bean 'userServiceImpl': AutowiredFieldElement for private es.unican.meteo.dao.UserMapper es.unican.meteo.service.impl.UserServiceImpl.userMapper
19:38:54,268 INFO http-8080-1 support.DefaultListableBeanFactory:433 - Destroying singletons in org.springframework.beans.factory.support.DefaultListableBeanFactory@56088b29: defining beans [myController,roleService,userServiceImpl,org.springframework.context.annotation.internalConfigurationAnnotationProcessor,org.springframework.context.annotation.internalAutowiredAnnotationProcessor,org.springframework.context.annotation.internalRequiredAnnotationProcessor,org.springframework.context.annotation.internalCommonAnnotationProcessor,org.springframework.web.servlet.mvc.method.annotation.RequestMappingHandlerMapping#0,org.springframework.format.support.FormattingConversionServiceFactoryBean#0,org.springframework.web.servlet.mvc.method.annotation.RequestMappingHandlerAdapter#0,org.springframework.web.servlet.handler.MappedInterceptor#0,org.springframework.web.servlet.mvc.method.annotation.ExceptionHandlerExceptionResolver#0,org.springframework.web.servlet.mvc.annotation.ResponseStatusExceptionResolver#0,org.springframework.web.servlet.mvc.support.DefaultHandlerExceptionResolver#0,org.springframework.web.servlet.handler.BeanNameUrlHandlerMapping,org.springframework.web.servlet.mvc.HttpRequestHandlerAdapter,org.springframework.web.servlet.mvc.SimpleControllerHandlerAdapter,org.springframework.web.servlet.view.InternalResourceViewResolver#0,org.springframework.context.annotation.ConfigurationClassPostProcessor$ImportAwareBeanPostProcessor#0]; root of factory hierarchy
19:38:54,279 ERROR http-8080-1 servlet.DispatcherServlet:457 - Context initialization failed
我已经审查了有关此主题的一些问题,但没有找到解决问题的方法。也许我正在跳过某些内容,但我不确定。我试图更改组件扫描,但没有结果。
当我尝试访问/SPRING-MVC/getUsers.go时,出现这些错误。
我不知道这些bean是否必须放置在app-config(applicationContext)或servlet.xml中,因为这有点令人困惑…
谢谢
问题答案:
您的配置很奇怪…
首先排除明显
我在您的中看不到根Web应用程序上下文配置web.xml
。可能是您忘记添加这段代码了吗?
<context-param>
<param-name>contextConfigLocation</param-name>
<param-value>
WEB-INF/app-config.xml
</param-value>
</context-param>
<listener>
<listener-class>org.springframework.web.context.ContextLoaderListener</listener-class>
</listener>
现在有点理论
Spring理论的一点-Spring使用Web应用程序的应用程序上下文层次结构:
- 顶级Web应用程序上下文由加载
ContextLoaderListener
- 然后每个
DispatcherServlet
实例都有单独的上下文
当实例化一个新bean时,它可以从定义它的上下文中或从父上下文中获取依赖关系。这样就可以在根上下文(服务,DAO等)中定义公共bean,并在servlet应用程序上下文中具有请求处理bean,因为每个servlet可以具有自己的一组控制器,视图处理程序,…。
最后但并非最不重要的-您的错误
您正在根上下文中配置MVC。那是错误的。<mvc:
从那里删除上下文。
您还可以通过<context:component- scan>
基本软件包中的在根上下文中注册控制器。使组件仅在services
软件包上进行扫描,或者将您的类分为两个顶级软件包core
(对于root
bean)和servlet
(对于servlet bean)。