dao在serviceimpl类中始终为null

Question

以下是我的代码。我正在使用远程处理来获取对服务的引用。一旦我得到服务引用并尝试获取event.dao调用我在EventServiceImpl类中获得NPE。当我使用基于xml的配置时，它可以工作，但我希望它是基于注释的。

EventDao.class

public interface EventDao {

    void saveEvent(Event employee);

    List<Event> findAllEvents();

    void deleteEmployeeBySsn(String ssn);

    Event findBySsn(String ssn);

    void updateEvent(Event employee);
}

EventImplDao.class

@Repository
public class EventDaoImpl extends AbstractDao implements EventDao{

    public void saveEvent(Event employee) {
        persist(employee);
    }

    @SuppressWarnings("unchecked")
    public List<Event> findAllEvents() {
        Criteria criteria = getSession().createCriteria(Event.class);
        return (List<Event>) criteria.list();
    }

EventServiceImpl

@Service
@Transactional
public class EventServiceImpl implements EventService{

    private EventDao eventDao;

    public void setEventDao(EventDao eventDao) {
        this.eventDao = eventDao;
    }

    public void saveEvent(Event employee) {
        eventDao.saveEvent(employee);
    }

    public List<Event> findAllEvents() {
        return eventDao.findAllEvents();
    }

EventService

@ServiceInterface
public interface EventService {

    void saveEvent(Event employee);

    List<Event> findAllEvents();

    void deleteEmployeeBySsn(String ssn);

    Event findBySsn(String ssn);

    void updateEvent(Event employee);
}

的AppConfig

@Configuration
@ComponentScan(basePackages = "com.xxx.spring")
public class AppConfig {

    @Bean
    public com.xxx.spring.dao.EventDao EventDao() {
        return new EventDaoImpl();
    }

    @Bean
    public com.xxxx.spring.service.EventService eventService() {
        return new EventServiceImpl();
    }

hibernateconfig类

@Configuration
@EnableTransactionManagement
@ComponentScan({ "com.xxxxx.configuration.hib" })
public class HibernateConfiguration {

    @Bean
    public LocalSessionFactoryBean sessionFactory() {
        LocalSessionFactoryBean sessionFactory = new LocalSessionFactoryBean();
        sessionFactory.setDataSource(dataSource());
        sessionFactory.setPackagesToScan(new String[] { "com.xxxxxx.spring.component" });
        sessionFactory.setHibernateProperties(hibProperties());
        return sessionFactory;
     }

    @Bean
    public DataSource dataSource() {
        FileUtils ft = new FileUtils();
        ft.getProperties();
        DriverManagerDataSource driverManagerDataSource = new DriverManagerDataSource();
        driverManagerDataSource.setDriverClassName(ft.getProperties().getProperty("driver"));
        driverManagerDataSource.setUrl(ft.getProperties().getProperty("url"));
        driverManagerDataSource.setUsername(ft.getProperties().getProperty("username"));
        driverManagerDataSource.setPassword(ft.getProperties().getProperty("password"));
        return driverManagerDataSource;
    }
    private Properties hibProperties() {
        Properties properties = new Properties();
        properties.put(Environment.DIALECT, "org.hibernate.dialect.SQLServer2012Dialect");
        properties.put(Environment.SHOW_SQL, false);
        return properties;
    }

    @Bean
    @Autowired
    public HibernateTransactionManager transactionManager(SessionFactory s) {
       HibernateTransactionManager txManager = new HibernateTransactionManager();
       txManager.setSessionFactory(s);
       return txManager;
    }
}

堆栈跟踪：

HTTP Status 500 - Request processing failed; nested exception is java.lang.NullPointerException

type Exception report

message Request processing failed; nested exception is java.lang.NullPointerException

description The server encountered an internal error that prevented it from fulfilling this request.

exception

org.springframework.web.util.NestedServletException: Request processing failed; nested exception is java.lang.NullPointerException
    org.springframework.web.servlet.FrameworkServlet.processRequest(FrameworkServlet.java:973)
    org.springframework.web.servlet.FrameworkServlet.doGet(FrameworkServlet.java:852)
    javax.servlet.http.HttpServlet.service(HttpServlet.java:620)
    org.springframework.web.servlet.FrameworkServlet.service(FrameworkServlet.java:837)
    javax.servlet.http.HttpServlet.service(HttpServlet.java:727)
    org.apache.tomcat.websocket.server.WsFilter.doFilter(WsFilter.java:52)
    org.springframework.orm.hibernate4.support.OpenSessionInViewFilter.doFilterInternal(OpenSessionInViewFilter.java:152)
    org.springframework.web.filter.OncePerRequestFilter.doFilter(OncePerRequestFilter.java:108)
root cause

java.lang.NullPointerException
    com.xxxx.spring.service.Impl.EventServiceImpl.findAllEvents(EventServiceImpl.java:28)
    sun.reflect.NativeMethodAccessorImpl.invoke0(Native Method)
    sun.reflect.NativeMethodAccessorImpl.invoke(Unknown Source)
    sun.reflect.DelegatingMethodAccessorImpl.invoke(Unknown Source)
    java.lang.reflect.Method.invoke(Unknown Source)
    org.springframework.aop.support.AopUtils.invokeJoinpointUsingReflection(AopUtils.java:317)
    org.springframework.aop.framework.ReflectiveMethodInvocation.invokeJoinpoint(ReflectiveMethodInvocation.java:190)
    org.springframework.aop.framework.ReflectiveMethodInvocation.proceed(ReflectiveMethodInvocation.java:157)
    org.springframework.transaction.interceptor.TransactionInterceptor$1.proceedWithInvocation(TransactionInterceptor.java:98)
    org.springframework.transaction.interceptor.TransactionAspectSupport.invokeWithinTransaction(TransactionAspectSupport.java:262)
    org.springframework.transaction.interceptor.TransactionInterceptor.invoke(TransactionInterceptor.java:95)
    org.springframework.aop.framework.ReflectiveMethodInvocation.proceed(ReflectiveMethodInvocation.java:179)
    org.springframework.aop.framework.JdkDynamicAopProxy.invoke(JdkDynamicAopProxy.java:207)
    com.sun.proxy.$Proxy24.findAllEvents(Unknown Source)
    sun.reflect.NativeMethodAccessorImpl.invoke0(Native Method)
    sun.reflect.NativeMethodAccessorImpl.invoke(Unknown Source)
    sun.reflect.DelegatingMethodAccessorImpl.invoke(Unknown Source)
    java.lang.reflect.Method.invoke(Unknown Source)
    org.springframework.aop.support.AopUtils.invokeJoinpointUsingReflection(AopUtils.java:317)
    org.springframework.aop.framework.ReflectiveMethodInvocation.invokeJoinpoint(ReflectiveMethodInvocation.java:190)
    org.springframework.aop.framework.ReflectiveMethodInvocation.proceed(ReflectiveMethodInvocation.java:157)
    org.springframework.remoting.support.RemoteInvocationTraceInterceptor.invoke(RemoteInvocationTraceInterceptor.java:78)
    org.springframework.aop.framework.ReflectiveMethodInvocation.proceed(ReflectiveMethodInvocation.java:179)
    org.springframework.aop.framework.JdkDynamicAopProxy.invoke(JdkDynamicAopProxy.java:207)
    com.sun.proxy.$Proxy25.findAllEvents(Unknown Source)
    sun.reflect.NativeMethodAccessorImpl.invoke0(Native Method)
    sun.reflect.NativeMethodAccessorImpl.invoke(Unknown Source)
    sun.reflect.DelegatingMethodAccessorImpl.invoke(Unknown Source)
    java.lang.reflect.Method.invoke(Unknown Source)
    org.springframework.remoting.support.RemoteInvocation.invoke(RemoteInvocation.java:212)
    org.springframework.remoting.support.DefaultRemoteInvocationExecutor.invoke(DefaultRemoteInvocationExecutor.java:39)
    org.springframework.remoting.support.RemoteInvocationBasedExporter.invoke(RemoteInvocationBasedExporter.java:78)
    org.springframework.remoting.rmi.RmiBasedExporter.invoke(RmiBasedExporter.java:73)
    org.springframework.remoting.rmi.RmiInvocationWrapper.invoke(RmiInvocationWrapper.java:74)
    sun.reflect.NativeMethodAccessorImpl.invoke0(Native Method)
    sun.reflect.NativeMethodAccessorImpl.invoke(Unknown Source)
    sun.reflect.DelegatingMethodAccessorImpl.invoke(Unknown Source)
    java.lang.reflect.Method.invoke(Unknown Source)
    sun.rmi.server.UnicastServerRef.dispatch(Unknown Source)
    sun.rmi.transport.Transport$1.run(Unknown Source)
    sun.rmi.transport.Transport$1.run(Unknown Source)
    java.security.AccessController.doPrivileged(Native Method)
    sun.rmi.transport.Transport.serviceCall(Unknown Source)
    sun.rmi.transport.tcp.TCPTransport.handleMessages(Unknown Source)
    sun.rmi.transport.tcp.TCPTransport$ConnectionHandler.run0(Unknown Source)
    sun.rmi.transport.tcp.TCPTransport$ConnectionHandler.lambda$run$256(Unknown Source)
    java.security.AccessController.doPrivileged(Native Method)
    sun.rmi.transport.tcp.TCPTransport$ConnectionHandler.run(Unknown Source)
    java.util.concurrent.ThreadPoolExecutor.runWorker(Unknown Source)
    java.util.concurrent.ThreadPoolExecutor$Worker.run(Unknown Source)
    java.lang.Thread.run(Unknown Source)
    org.springframework.remoting.support.RemoteInvocationUtils.fillInClientStackTraceIfPossible(RemoteInvocationUtils.java:45)
    org.springframework.remoting.rmi.RmiClientInterceptor.doInvoke(RmiClientInterceptor.java:353)
    org.springframework.remoting.rmi.RmiClientInterceptor.invoke(RmiClientInterceptor.java:260)
    org.springframework.aop.framework.ReflectiveMethodInvocation.proceed(ReflectiveMethodInvocation.java:179)
    org.springframework.aop.framework.JdkDynamicAopProxy.invoke(JdkDynamicAopProxy.java:207)
    com.sun.proxy.$Proxy30.findAllEvents(Unknown Source)
    com.xxxx.controller.WebController.initiateEventsPage(WebController.java:35)
    sun.reflect.NativeMethodAccessorImpl.invoke0(Native Method)
    sun.reflect.NativeMethodAccessorImpl.invoke(Unknown Source)
    sun.reflect.DelegatingMethodAccessorImpl.invoke(Unknown Source)
    java.lang.reflect.Method.invoke(Unknown Source)
    org.springframework.web.method.support.InvocableHandlerMethod.invoke(InvocableHandlerMethod.java:215)
    org.springframework.web.method.support.InvocableHandlerMethod.invokeForRequest(InvocableHandlerMethod.java:132)
    org.springframework.web.servlet.mvc.method.annotation.ServletInvocableHandlerMethod.invokeAndHandle(ServletInvocableHandlerMethod.java:104)
    org.springframework.web.servlet.mvc.method.annotation.RequestMappingHandlerAdapter.invokeHandleMethod(RequestMappingHandlerAdapter.java:749)
    org.springframework.web.servlet.mvc.method.annotation.RequestMappingHandlerAdapter.handleInternal(RequestMappingHandlerAdapter.java:689)
    org.springframework.web.servlet.mvc.method.AbstractHandlerMethodAdapter.handle(AbstractHandlerMethodAdapter.java:83)
    org.springframework.web.servlet.DispatcherServlet.doDispatch(DispatcherServlet.java:938)
    org.springframework.web.servlet.DispatcherServlet.doService(DispatcherServlet.java:870)
    org.springframework.web.servlet.FrameworkServlet.processRequest(FrameworkServlet.java:961)
    org.springframework.web.servlet.FrameworkServlet.doGet(FrameworkServlet.java:852)
    javax.servlet.http.HttpServlet.service(HttpServlet.java:620)
    org.springframework.web.servlet.FrameworkServlet.service(FrameworkServlet.java:837)
    javax.servlet.http.HttpServlet.service(HttpServlet.java:727)
    org.apache.tomcat.websocket.server.WsFilter.doFilter(WsFilter.java:52)
    org.springframework.orm.hibernate4.support.OpenSessionInViewFilter.doFilterInternal(OpenSessionInViewFilter.java:152)
    org.springframework.web.filter.OncePerRequestFilter.doFilter(OncePerRequestFilter.java:108)
note The full stack trace of the root cause is available in the Apache Tomcat/7.0.57 logs.

现在出现新错误。我认为导致事件导致事件DaoIml附加@Repository。

Caused by: org.springframework.beans.factory.BeanCreationException: Could not autowire field: private com.xxxxx.spring.dao.EventDao com.xxx.spring.service.Impl.EventServiceImpl.eventDao; nested exception is org.springframework.beans.factory.NoUniqueBeanDefinitionException: No qualifying bean of type [com.xxxi.spring.dao.EventDao] is defined: expected single matching bean but found 2: eventDaoImpl,EventDao
    at org.springframework.beans.factory.annotation.AutowiredAnnotationBeanPostProcessor$AutowiredFieldElement.inject(AutowiredAnnotationBeanPostProcessor.java:508)
    at org.springframework.beans.factory.annotation.InjectionMetadata.inject(InjectionMetadata.java:87)
    at org.springframework.beans.factory.annotation.AutowiredAnnotationBeanPostProcessor.postProcessPropertyValues(AutowiredAnnotationBeanPostProcessor.java:289)
    ... 26 more
Caused by: org.springframework.beans.factory.NoUniqueBeanDefinitionException: No qualifying bean of type [comxxx.i.spring.dao.EventDao] is defined: expected single matching bean but found 2: eventDaoImpl,EventDao
    at org.springframework.beans.factory.support.DefaultListableBeanFactory.doResolveDependency(DefaultListableBeanFactory.java:970)
    at org.springframework.beans.factory.support.DefaultListableBeanFactory.resolveDependency(DefaultListableBeanFactory.java:858)
    at org.springframework.beans.factory.annotation.AutowiredAnnotationBeanPostProcessor$AutowiredFieldElement.inject(AutowiredAnnotationBeanPostProcessor.java:480)
    ... 28 more

Answer 1

尝试在dao @Autowired

中使用注释

@Autowired
private EventDao eventDao;