java - Spring依赖注入(inject)失败

Question

我想使用 spring 依赖注入(inject)在我的 Web 应用程序中注入(inject)一些对象。

在 EtudiantServiceImpl 类(具有 @Service 注释)中，我有:

@Autowired
private IEtudiantDao etudiantDao;

在 EtudiantAction 类(具有 @Service 注释)中，我有:

@Autowired
private EtudiantServiceImpl etudiantService;
@Autowired
public Etudiant etudiant;

但是当我运行我的应用程序时，我收到此错误消息:

2015-01-02 06:14:38,741 ERROR (org.apache.struts2.dispatcher.Dispatcher:38) - Exception occurred during processing request: Unable to instantiate Action, tp.ihm.gestionEtudiants.web.EtudiantAction,  defined for 'etudiants' in namespace '/'Error creating bean with name 'tp.ihm.gestionEtudiants.web.EtudiantAction': Injection of autowired dependencies failed; nested exception is org.springframework.beans.factory.BeanCreationException: Could not autowire field: private tp.ihm.gestionEtudiants.service.EtudiantServiceImpl tp.ihm.gestionEtudiants.web.EtudiantAction.etudiantService; nested exception is org.springframework.beans.factory.NoSuchBeanDefinitionException: No matching bean of type [tp.ihm.gestionEtudiants.service.EtudiantServiceImpl] 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)}
Unable to instantiate Action, tp.ihm.gestionEtudiants.web.EtudiantAction,  defined for 'etudiants' in namespace '/'Error creating bean with name 'tp.ihm.gestionEtudiants.web.EtudiantAction': Injection of autowired dependencies failed; nested exception is org.springframework.beans.factory.BeanCreationException: Could not autowire field: private tp.ihm.gestionEtudiants.service.EtudiantServiceImpl tp.ihm.gestionEtudiants.web.EtudiantAction.etudiantService; nested exception is org.springframework.beans.factory.NoSuchBeanDefinitionException: No matching bean of type [tp.ihm.gestionEtudiants.service.EtudiantServiceImpl] 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)}
    at com.opensymphony.xwork2.DefaultActionInvocation.createAction(DefaultActionInvocation.java:316)
    at com.opensymphony.xwork2.DefaultActionInvocation.init(DefaultActionInvocation.java:397)
    at com.opensymphony.xwork2.DefaultActionProxy.prepare(DefaultActionProxy.java:194)
    at org.apache.struts2.impl.StrutsActionProxy.prepare(StrutsActionProxy.java:63)
    at org.apache.struts2.impl.StrutsActionProxyFactory.createActionProxy(StrutsActionProxyFactory.java:37)
    at com.opensymphony.xwork2.DefaultActionProxyFactory.createActionProxy(DefaultActionProxyFactory.java:58)
    at org.apache.struts2.dispatcher.Dispatcher.serviceAction(Dispatcher.java:552)
    at org.apache.struts2.dispatcher.ng.ExecuteOperations.executeAction(ExecuteOperations.java:77)
    at org.apache.struts2.dispatcher.ng.filter.StrutsPrepareAndExecuteFilter.doFilter(StrutsPrepareAndExecuteFilter.java:99)
    at org.apache.catalina.core.ApplicationFilterChain.internalDoFilter(ApplicationFilterChain.java:239)
    at org.apache.catalina.core.ApplicationFilterChain.doFilter(ApplicationFilterChain.java:206)
    at org.apache.catalina.core.StandardWrapperValve.invoke(StandardWrapperValve.java:219)
    at org.apache.catalina.core.StandardContextValve.invoke(StandardContextValve.java:106)
    at org.apache.catalina.authenticator.AuthenticatorBase.invoke(AuthenticatorBase.java:501)
    at org.apache.catalina.core.StandardHostValve.invoke(StandardHostValve.java:142)
    at org.apache.catalina.valves.ErrorReportValve.invoke(ErrorReportValve.java:79)
    at org.apache.catalina.valves.AbstractAccessLogValve.invoke(AbstractAccessLogValve.java:610)
    at org.apache.catalina.core.StandardEngineValve.invoke(StandardEngineValve.java:88)
    at org.apache.catalina.connector.CoyoteAdapter.service(CoyoteAdapter.java:537)
    at org.apache.coyote.http11.AbstractHttp11Processor.process(AbstractHttp11Processor.java:1085)
    at org.apache.coyote.AbstractProtocol$AbstractConnectionHandler.process(AbstractProtocol.java:658)
    at org.apache.coyote.http11.Http11NioProtocol$Http11ConnectionHandler.process(Http11NioProtocol.java:222)
    at org.apache.tomcat.util.net.NioEndpoint$SocketProcessor.doRun(NioEndpoint.java:1556)
    at org.apache.tomcat.util.net.NioEndpoint$SocketProcessor.run(NioEndpoint.java:1513)
    at java.util.concurrent.ThreadPoolExecutor.runWorker(ThreadPoolExecutor.java:1142)
    at java.util.concurrent.ThreadPoolExecutor$Worker.run(ThreadPoolExecutor.java:617)
    at org.apache.tomcat.util.threads.TaskThread$WrappingRunnable.run(TaskThread.java:61)
    at java.lang.Thread.run(Thread.java:745)
Caused by: org.springframework.beans.factory.BeanCreationException: Error creating bean with name 'tp.ihm.gestionEtudiants.web.EtudiantAction': Injection of autowired dependencies failed; nested exception is org.springframework.beans.factory.BeanCreationException: Could not autowire field: private tp.ihm.gestionEtudiants.service.EtudiantServiceImpl tp.ihm.gestionEtudiants.web.EtudiantAction.etudiantService; nested exception is org.springframework.beans.factory.NoSuchBeanDefinitionException: No matching bean of type [tp.ihm.gestionEtudiants.service.EtudiantServiceImpl] 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)}
    at org.springframework.beans.factory.annotation.AutowiredAnnotationBeanPostProcessor.postProcessPropertyValues(AutowiredAnnotationBeanPostProcessor.java:287)
    at org.springframework.beans.factory.support.AbstractAutowireCapableBeanFactory.populateBean(AbstractAutowireCapableBeanFactory.java:1073)
    at org.springframework.beans.factory.support.AbstractAutowireCapableBeanFactory.autowireBeanProperties(AbstractAutowireCapableBeanFactory.java:373)
    at com.opensymphony.xwork2.spring.SpringObjectFactory.autoWireBean(SpringObjectFactory.java:203)
    at com.opensymphony.xwork2.spring.SpringObjectFactory.buildBean(SpringObjectFactory.java:183)
    at com.opensymphony.xwork2.spring.SpringObjectFactory.buildBean(SpringObjectFactory.java:154)
    at com.opensymphony.xwork2.ObjectFactory.buildBean(ObjectFactory.java:171)
    at com.opensymphony.xwork2.factory.DefaultActionFactory.buildAction(DefaultActionFactory.java:22)
    at com.opensymphony.xwork2.ObjectFactory.buildAction(ObjectFactory.java:141)
    at com.opensymphony.xwork2.DefaultActionInvocation.createAction(DefaultActionInvocation.java:297)
    ... 27 more
Caused by: org.springframework.beans.factory.BeanCreationException: Could not autowire field: private tp.ihm.gestionEtudiants.service.EtudiantServiceImpl tp.ihm.gestionEtudiants.web.EtudiantAction.etudiantService; nested exception is org.springframework.beans.factory.NoSuchBeanDefinitionException: No matching bean of type [tp.ihm.gestionEtudiants.service.EtudiantServiceImpl] 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)}
    at org.springframework.beans.factory.annotation.AutowiredAnnotationBeanPostProcessor$AutowiredFieldElement.inject(AutowiredAnnotationBeanPostProcessor.java:506)
    at org.springframework.beans.factory.annotation.InjectionMetadata.inject(InjectionMetadata.java:84)
    at org.springframework.beans.factory.annotation.AutowiredAnnotationBeanPostProcessor.postProcessPropertyValues(AutowiredAnnotationBeanPostProcessor.java:284)
    ... 36 more
Caused by: org.springframework.beans.factory.NoSuchBeanDefinitionException: No matching bean of type [tp.ihm.gestionEtudiants.service.EtudiantServiceImpl] found for dependency: expected at least 1 bean which qualifies as autowire candidate for this dependency. Dependency annotations: {@org.springframework.beans.factory.annotation.Autowired(required=true)}
    at org.springframework.beans.factory.support.DefaultListableBeanFactory.raiseNoSuchBeanDefinitionException(DefaultListableBeanFactory.java:924)
    at org.springframework.beans.factory.support.DefaultListableBeanFactory.doResolveDependency(DefaultListableBeanFactory.java:793)
    at org.springframework.beans.factory.support.DefaultListableBeanFactory.resolveDependency(DefaultListableBeanFactory.java:707)
    at org.springframework.beans.factory.annotation.AutowiredAnnotationBeanPostProcessor$AutowiredFieldElement.inject(AutowiredAnnotationBeanPostProcessor.java:478)
    ... 38 more

这是应用程序上下文文件:

<!-- Configure jdbc.properties -->
    <bean id="propertyConfigurer"
        class="org.springframework.beans.factory.config.PropertyPlaceholderConfigurer"
        p:location="/WEB-INF/jdbc.properties" />

    <!-- Data Source configuration -->
    <bean id="dataSource"
        class="org.springframework.jdbc.datasource.DriverManagerDataSource">

        <property name="driverClassName">
            <value>${jdbc.driverClassName}</value>
        </property>
        <property name="url">
            <value>${jdbc.databaseurl}</value>
        </property>
        <property name="username">
            <value>${jdbc.username}</value>
        </property>
        <property name="password">
            <value>${jdbc.password}</value>
        </property>
   </bean>

    <!-- Configure hibernate session factory -->    
    <bean id="sessionFactory"
        class="org.springframework.orm.hibernate3.LocalSessionFactoryBean">
        <property name="dataSource" ref="dataSource" />
        <property name="configLocation">
            <value>classpath:hibernate.cfg.xml</value>
        </property>
        <property name="configurationClass">            
            <value>org.hibernate.cfg.AnnotationConfiguration</value>        
        </property>
        <property name="hibernateProperties">
            <props>
                <prop key="hibernate.dialect">${jdbc.dialect}</prop>
                <prop key="hibernate.show_sql">true</prop>
            </props>
        </property>
    </bean>
    <!-- Run SQL queries in transactions -->
    <tx:annotation-driven />
    <context:annotation-config></context:annotation-config>
    <bean id="transactionManager"
        class="org.springframework.orm.hibernate3.HibernateTransactionManager">
        <property name="sessionFactory" ref="sessionFactory" />
    </bean>

</beans>

编辑1:

将这一行添加到我的 spring 配置文件后:

<context:component-scan base-package="/" />

它解决了这个问题，但现在我收到另一条错误消息:

org.springframework.beans.factory.BeanCreationException: Error creating bean with name 'genericDaoImpl' defined in file [C:\Users\Aimad\workspace\.metadata\.plugins\org.eclipse.wst.server.core\tmp0\wtpwebapps\TP_WEB_GestionEtudiants\WEB-INF\classes\tp\generic\dao\GenericDaoImpl.class]: Invocation of init method failed; nested exception is java.lang.IllegalArgumentException: 'sessionFactory' or 'hibernateTemplate' is required
    at org.springframework.beans.factory.support.AbstractAutowireCapableBeanFactory.initializeBean(AbstractAutowireCapableBeanFactory.java:1422)
    at org.springframework.beans.factory.support.AbstractAutowireCapableBeanFactory.doCreateBean(AbstractAutowireCapableBeanFactory.java:518)
    at org.springframework.beans.factory.support.AbstractAutowireCapableBeanFactory.createBean(AbstractAutowireCapableBeanFactory.java:455)
    at org.springframework.beans.factory.support.AbstractBeanFactory$1.getObject(AbstractBeanFactory.java:293)
    at org.springframework.beans.factory.support.DefaultSingletonBeanRegistry.getSingleton(DefaultSingletonBeanRegistry.java:222)
    at org.springframework.beans.factory.support.AbstractBeanFactory.doGetBean(AbstractBeanFactory.java:290)
    at org.springframework.beans.factory.support.AbstractBeanFactory.getBean(AbstractBeanFactory.java:192)
    at org.springframework.beans.factory.support.DefaultListableBeanFactory.preInstantiateSingletons(DefaultListableBeanFactory.java:585)
    at org.springframework.context.support.AbstractApplicationContext.finishBeanFactoryInitialization(AbstractApplicationContext.java:895)
    at org.springframework.context.support.AbstractApplicationContext.refresh(AbstractApplicationContext.java:425)
    at org.springframework.web.context.ContextLoader.createWebApplicationContext(ContextLoader.java:282)
    at org.springframework.web.context.ContextLoader.initWebApplicationContext(ContextLoader.java:204)
    at org.springframework.web.context.ContextLoaderListener.contextInitialized(ContextLoaderListener.java:47)
    at org.apache.catalina.core.StandardContext.listenerStart(StandardContext.java:4772)
    at org.apache.catalina.core.StandardContext.startInternal(StandardContext.java:5196)
    at org.apache.catalina.util.LifecycleBase.start(LifecycleBase.java:150)
    at org.apache.catalina.core.ContainerBase$StartChild.call(ContainerBase.java:1409)
    at org.apache.catalina.core.ContainerBase$StartChild.call(ContainerBase.java:1399)
    at java.util.concurrent.FutureTask.run(FutureTask.java:266)
    at java.util.concurrent.ThreadPoolExecutor.runWorker(ThreadPoolExecutor.java:1142)
    at java.util.concurrent.ThreadPoolExecutor$Worker.run(ThreadPoolExecutor.java:617)
    at java.lang.Thread.run(Thread.java:745)
Caused by: java.lang.IllegalArgumentException: 'sessionFactory' or 'hibernateTemplate' is required
    at org.springframework.orm.hibernate3.support.HibernateDaoSupport.checkDaoConfig(HibernateDaoSupport.java:118)
    at org.springframework.dao.support.DaoSupport.afterPropertiesSet(DaoSupport.java:44)
    at org.springframework.beans.factory.support.AbstractAutowireCapableBeanFactory.invokeInitMethods(AbstractAutowireCapableBeanFactory.java:1479)
    at org.springframework.beans.factory.support.AbstractAutowireCapableBeanFactory.initializeBean(AbstractAutowireCapableBeanFactory.java:1419)
    ... 21 more

这是 GenericDaoImpl 类:

@Repository
public class GenericDaoImpl<T, PK extends Serializable> extends HibernateDaoSupport implements GenericDao<T,PK> {

    private Class<T> entityClass;

    public GenericDaoImpl(){
    }

    public GenericDaoImpl(final Class<T> entityClass){
        this.entityClass = entityClass;
    }

    public T getEntity(PK id) {
        return (T) getHibernateTemplate().get(entityClass, id);
    }

    public List<T> getAll(){
        return getHibernateTemplate().loadAll(entityClass);
    }

    public PK save(T entity) {
        return (PK) getHibernateTemplate().save(entity);
    }

    public void delete(PK id) {
        if(getEntity(id) != null)
            getHibernateTemplate().delete(getEntity(id));
    }

    public void update(T entity) {
        getHibernateTemplate().update(entity);

    }

Answer 1

您必须提到自动扫描所有 bean。

请在 Spring 配置 xml 文件中指定以下配置:

<context:component-scan base-package="com.x.y.z" />

Tutorial

Here是以编程方式配置自动扫描。