spring 注入失敗報錯
阿新 • • 發佈：2018-11-22
報錯程式碼片段：
Error creating bean with name 'itemServiceImpl': Injection of autowired dependencies failed; nested exception is org.springframework.beans.factory.BeanCreationException: Could not autowire field: private com.taotao.search.mapper.ItemMapper com.taotao.search.service.ItemServiceImpl.itemMapper; nested exception is org.springframework.beans.factory.NoSuchBeanDefinitionException: No qualifying bean of type [com.taotao.search.mapper.ItemMapper] 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)}
網上的方法都試過了，註解加了，mapper.xml的namespace什麼的也檢查了好幾遍，都找不到錯。
因為專案裡放了一個*.*.mapper包和*.*.dao包，一度以為這兩個包可能有衝突，仔細想想應該也不是這個原因。
經過再三的檢查，偶然發現applicationContext-dao的配置檔案裡沒有掃描mapper的包。添上之後問題解決。
附上工程目錄和配置檔案：
applicationContext-dao.xml
<?xml version="1.0" encoding="UTF-8"?> <beans xmlns="http://www.springframework.org/schema/beans" xmlns:context="http://www.springframework.org/schema/context" xmlns:p="http://www.springframework.org/schema/p" xmlns:aop="http://www.springframework.org/schema/aop" xmlns:tx="http://www.springframework.org/schema/tx" xmlns:xsi="http://www.w3.org/2001/XMLSchema-instance" xsi:schemaLocation="http://www.springframework.org/schema/beans http://www.springframework.org/schema/beans/spring-beans-4.0.xsd http://www.springframework.org/schema/context http://www.springframework.org/schema/context/spring-context-4.0.xsd http://www.springframework.org/schema/aop http://www.springframework.org/schema/aop/spring-aop-4.0.xsd http://www.springframework.org/schema/tx http://www.springframework.org/schema/tx/spring-tx-4.0.xsd http://www.springframework.org/schema/util http://www.springframework.org/schema/util/spring-util-4.0.xsd"> <!-- 資料庫連線池 --> <!-- 載入配置檔案 --> <context:property-placeholder location="classpath:properties/*.properties" /> <!-- 資料庫連線池 --> <bean id="dataSource" class="com.alibaba.druid.pool.DruidDataSource" destroy-method="close"> <property name="url" value="${jdbc.url}" /> <property name="username" value="${jdbc.username}" /> <property name="password" value="${jdbc.password}" /> <property name="driverClassName" value="${jdbc.driver}" /> <property name="maxActive" value="10" /> <property name="minIdle" value="5" /> </bean> <!-- 讓spring管理sqlsessionfactory 使用mybatis和spring整合包中的 --> <bean id="sqlSessionFactory" class="org.mybatis.spring.SqlSessionFactoryBean"> <!-- 資料庫連線池 --> <property name="dataSource" ref="dataSource" /> <!-- 載入mybatis的全域性配置檔案 --> <property name="configLocation" value="classpath:mybatis/SqlMapConfig.xml" /> </bean> <bean class="org.mybatis.spring.mapper.MapperScannerConfigurer"> <!-- 給出需要掃描Dao介面包 --> <property name="basePackage" value="com.taotao.dao,com.taotao.search.dao,com.taotao.search.mapper" /> </bean> </beans>
注意配置檔案裡的最後一個<bean>,裡面配置上掃描dao包和mapper包
<bean class="org.mybatis.spring.mapper.MapperScannerConfigurer">
<!-- 給出需要掃描Dao介面包 -->
<property name="basePackage" value="com.taotao.dao,com.taotao.search.dao,com.taotao.search.mapper" />
</bean>
applicationContent-service.xml
<?xml version="1.0" encoding="UTF-8"?>
<beans xmlns="http://www.springframework.org/schema/beans"
xmlns:context="http://www.springframework.org/schema/context" xmlns:p="http://www.springframework.org/schema/p"
xmlns:aop="http://www.springframework.org/schema/aop" xmlns:tx="http://www.springframework.org/schema/tx"
xmlns:xsi="http://www.w3.org/2001/XMLSchema-instance"
xsi:schemaLocation="http://www.springframework.org/schema/beans http://www.springframework.org/schema/beans/spring-beans-4.0.xsd
http://www.springframework.org/schema/context http://www.springframework.org/schema/context/spring-context-4.0.xsd
http://www.springframework.org/schema/aop http://www.springframework.org/schema/aop/spring-aop-4.0.xsd http://www.springframework.org/schema/tx http://www.springframework.org/schema/tx/spring-tx-4.0.xsd
http://www.springframework.org/schema/util http://www.springframework.org/schema/util/spring-util-4.0.xsd">
<!-- 包掃描器，掃描帶@Service註解的類,此處加逗號分開，寫成com.taotao.search.*會把controller掃描進來，引發父子容器問題 -->
<context:component-scan base-package="com.taotao.search.service"></context:component-scan>
<!-- 單機版solr客戶端 , 在這配置完成後就可以直接讓spring注入了 SolrServer是個抽象類，httpSolrServerhe clientSolrServer是其子類，一個是單機版，一個是叢集版-->
<bean id="httpSolrServer" class="org.apache.solr.client.solrj.impl.HttpSolrServer">
<constructor-arg name="baseURL" value="http://144.34.134.37:8080/solr"></constructor-arg>
</bean>
</beans>
注意配置檔案裡包掃描器中掃描service包。
<!-- 包掃描器，掃描帶@Service註解的類,此處加逗號分開，寫成com.taotao.search.*會把controller掃描進來，引發父子容器問題 -->
<context:component-scan base-package="com.taotao.search.service"></context:component-scan>
springmvc.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:p="http://www.springframework.org/schema/p"
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/mvc http://www.springframework.org/schema/mvc/spring-mvc-4.0.xsd
http://www.springframework.org/schema/context http://www.springframework.org/schema/context/spring-context.xsd">
<!-- 配置包掃描器 -->
<context:component-scan base-package="com.taotao.search.controller"></context:component-scan>
<!-- 配置註解驅動 -->
<mvc:annotation-driven/>
</beans>
這個配置檔案是配置controller包的掃描，因為父子容器的關係，controller包的掃描要和dao包、service包的掃描分開。
web.xml
最後是web.xml。配置spring掃描上面dao包、service包的配置檔案。配置springmvc掃描上面controller包的配置檔案。
<?xml version="1.0" encoding="UTF-8"?>
<web-app xmlns:xsi="http://www.w3.org/2001/XMLSchema-instance"
xmlns="http://java.sun.com/xml/ns/javaee" xmlns:web="http://java.sun.com/xml/ns/javaee/web-app_2_5.xsd"
xsi:schemaLocation="http://java.sun.com/xml/ns/javaee http://java.sun.com/xml/ns/javaee/web-app_2_5.xsd"
id="taotao" version="2.5">
<display-name>taotao-search</display-name>
<welcome-file-list>
<welcome-file>index.html</welcome-file>
<welcome-file>index.htm</welcome-file>
<welcome-file>index.jsp</welcome-file>
<welcome-file>default.html</welcome-file>
<welcome-file>default.htm</welcome-file>
<welcome-file>default.jsp</welcome-file>
</welcome-file-list>
<!-- 載入spring容器 -->
<context-param>
<param-name>contextConfigLocation</param-name>
<param-value>classpath:spring/applicationContext-*.xml</param-value>
</context-param>
<listener>
<listener-class>org.springframework.web.context.ContextLoaderListener</listener-class>
</listener>
<!-- 解決post亂碼 -->
<filter>
<filter-name>CharacterEncodingFilter</filter-name>
<filter-class>org.springframework.web.filter.CharacterEncodingFilter</filter-class>
<init-param>
<param-name>encoding</param-name>
<param-value>utf-8</param-value>
</init-param>
<!-- <init-param>
<param-name>forceEncoding</param-name>
<param-value>true</param-value>
</init-param> -->
</filter>
<filter-mapping>
<filter-name>CharacterEncodingFilter</filter-name>
<url-pattern>*</url-pattern>
</filter-mapping>
<!-- springmvc的前端控制器 -->
<servlet>
<servlet-name>taotao-search</servlet-name>
<servlet-class>org.springframework.web.servlet.DispatcherServlet</servlet-class>
<!-- contextConfigLocation不是必須的， 如果不配置contextConfigLocation， springmvc的配置檔案預設在：WEB-INF/servlet的name+"-servlet.xml" -->
<init-param>
<param-name>contextConfigLocation</param-name>
<param-value>classpath:spring/springmvc.xml</param-value>
</init-param>
<load-on-startup>1</load-on-startup>
</servlet>
<servlet-mapping>
<servlet-name>taotao-search</servlet-name>
<url-pattern>/search/*</url-pattern>
</servlet-mapping>
<!-- log4j配置檔案位置 -->
<context-param>
<param-name>log4jConfigLocation</param-name>
<param-value>classpath:log4j.properties</param-value>
</context-param>
<!-- 利用spring來使用log4j -->
<listener>
<listener-class>org.springframework.web.util.Log4jConfigListener</listener-class>
</listener>
</web-app>總結：
*dao.xml檔案配置資料庫連線層的包掃描。一般是*.*.dao或*.*.mapper，多個包時用“，”分隔。
*service.xml檔案配置服務層的包的掃描。一般是*.*.service包，多個時用“，”分隔。
springmvc.xml檔案配置檢視層的包的掃描。一般是*.*.controller包。
springmvc.xml為什麼不用*.controller命名？
可能是因為springmvc.xml屬於springmvc容器，dao.xml和service.xml屬於spring容器吧！
web.xml檔案則配置spring和springmvc分別掃描哪些配置檔案