使用 Flex 客户端时出现 Spring+Hibernate+Blazeds null 错误

Question

我的问题很简单，当我从独立应用程序运行 EventService 中的方法时（通过在 main() 中使用 ClassPathXmlApplicationContext ），一切正常。

@Service
@Transactional(readOnly = true)
public class EventService {
    Logger log = Logger.getLogger(EventService.class);
    @Autowired private EventDao eventDao;

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

    public List<Event> getAllContainsResource(int resourceId) {
        return eventDao.getAllWithResource(resourceId);
    }

    public String getName() {
        return "simpleName";
    }
}

当我在 tomcat（STS 上的内置服务器）上运行时，容器正确启动，但是当我将请求（通过 AMF 的 Flex 应用程序）发送到 getAll() 方法或 getAllContainsResource(int) *NullPointerException* 出现。它表明eventDao 为空。我不知道可能是什么原因，所以请帮忙。这是我的 applicationContext ：

<?xml version="1.0" encoding="UTF-8"?>
<beans>

    <!-- database connection -->
    <bean id="dataSource" class="org.apache.commons.dbcp.BasicDataSource" destroy-method="close">
        <property name="driverClassName" value="com.mysql.jdbc.Driver" />
        <property name="url" value="jdbc:mysql://localhost:3306/rapla" />
        <property name="username" value="root" />
        <property name="password" value="admin" />
    </bean>

    <bean id="sessionFactory" class="org.springframework.orm.hibernate3.LocalSessionFactoryBean">
        <property name="dataSource" ref="dataSource" />
        <property name="hibernateProperties">
            <value>
                hibernate.dialect=org.hibernate.dialect.MySQLInnoDBDialect
                hibernate.c3p0.min_size=5
                hibernate.c3p0.max_size=20
                hibernate.c3p0.timeout=1800
                hibernate.c3p0.max_statements=50
                hibernate.show_sql=true
                hibernate.format_sql=true
                hibernate.use_sql_comments=true
        </value>
        </property>
        <property name="configLocation">
            <value>classpath:hibernate.cfg.xml</value>
        </property>
        <property name="configurationClass">
            <value>org.hibernate.cfg.AnnotationConfiguration</value>
        </property>
    </bean>


    <bean id="txManager"
        class="org.springframework.orm.hibernate3.HibernateTransactionManager">
        <property name="sessionFactory" ref="sessionFactory" />
    </bean>

    <tx:annotation-driven transaction-manager="txManager" />

    <context:annotation-config />
    <context:component-scan base-package="org.pwsz.dao.hibernate" />
    <context:component-scan base-package="org.pwsz.services" />

    <flex:message-broker />

</beans>

独立应用程序的 XML 是相同的，当然没有

<flex:message-broker />

EventDaoImpl ：

@Repository
public class EventDaoImpl implements EventDao {

    Logger log = Logger.getLogger(EventDaoImpl.class);
    @Autowired private SessionFactory sessionFactory;

    public Event getById(int id) {
        return (Event) sessionFactory.getCurrentSession().get(Event.class, id);
    }

    public List<Event> getAll() {
        return sessionFactory.getCurrentSession().createCriteria(Event.class).list();
    }

    public List<Event> getAllWithResource(Integer id) {
        List<Event> resulu = sessionFactory.getCurrentSession()
            .createCriteria(Event.class)
            .createCriteria("appointments.teachers")
            .add(Restrictions.eq("resourceId", id))
            .list();

        return resulu;
    }
}

Spring-flex 连接工作正常，我可以使用 Flex 远程对象请求 getName 但发送其他两个请求会生成 null 异常。

我检查了

---

WebApp 中的问题（使用 spring mvc），一切正常。我发现这个问题会生成 Hibernate，当请求来自 Flex（使用 AMF 协议）时，它会为 DAO（它们是 @autowired）返回 null sessionFactory。

flex.messaging.MessageException: java.lang.NullPointerException : null
    at flex.messaging.services.remoting.adapters.JavaAdapter.invoke(JavaAdapter.java:444)
    at flex.messaging.services.RemotingService.serviceMessage(RemotingService.java:183)
    at flex.messaging.MessageBroker.routeMessageToService(MessageBroker.java:1400)
    at flex.messaging.endpoints.AbstractEndpoint.serviceMessage(AbstractEndpoint.java:1005)
    at flex.messaging.endpoints.AbstractEndpoint$$FastClassByCGLIB$$1a3ef066.invoke(<generated>)
    at net.sf.cglib.proxy.MethodProxy.invoke(MethodProxy.java:149)
    at org.springframework.aop.framework.Cglib2AopProxy$CglibMethodInvocation.invokeJoinpoint(Cglib2AopProxy.java:688)
    at org.springframework.aop.framework.ReflectiveMethodInvocation.proceed(ReflectiveMethodInvocation.java:150)
    at org.springframework.flex.core.MessageInterceptionAdvice.invoke(MessageInterceptionAdvice.java:66)
    at org.springframework.aop.framework.ReflectiveMethodInvocation.proceed(ReflectiveMethodInvocation.java:172)
    at org.springframework.aop.framework.adapter.ThrowsAdviceInterceptor.invoke(ThrowsAdviceInterceptor.java:124)
    at org.springframework.aop.framework.ReflectiveMethodInvocation.proceed(ReflectiveMethodInvocation.java:172)
    at org.springframework.aop.framework.Cglib2AopProxy$FixedChainStaticTargetInterceptor.intercept(Cglib2AopProxy.java:572)
    at flex.messaging.endpoints.AMFEndpoint$$EnhancerByCGLIB$$247a330d.serviceMessage(<generated>)
    at flex.messaging.endpoints.amf.MessageBrokerFilter.invoke(MessageBrokerFilter.java:103)
    at flex.messaging.endpoints.amf.LegacyFilter.invoke(LegacyFilter.java:158)
    at flex.messaging.endpoints.amf.SessionFilter.invoke(SessionFilter.java:44)
    at flex.messaging.endpoints.amf.BatchProcessFilter.invoke(BatchProcessFilter.java:67)
    at flex.messaging.endpoints.amf.SerializationFilter.invoke(SerializationFilter.java:166)
    at flex.messaging.endpoints.BaseHTTPEndpoint.service(BaseHTTPEndpoint.java:291)
    at flex.messaging.endpoints.AMFEndpoint$$EnhancerByCGLIB$$247a330d.service(<generated>)
    at org.springframework.flex.servlet.MessageBrokerHandlerAdapter.handle(MessageBrokerHandlerAdapter.java:109)
    at org.springframework.web.servlet.DispatcherServlet.doDispatch(DispatcherServlet.java:790)
    at org.springframework.web.servlet.DispatcherServlet.doService(DispatcherServlet.java:719)
    at org.springframework.web.servlet.FrameworkServlet.processRequest(FrameworkServlet.java:669)
    at org.springframework.web.servlet.FrameworkServlet.doPost(FrameworkServlet.java:585)
    at javax.servlet.http.HttpServlet.service(HttpServlet.java:637)
    at javax.servlet.http.HttpServlet.service(HttpServlet.java:717)
    at org.apache.catalina.core.ApplicationFilterChain.internalDoFilter(ApplicationFilterChain.java:290)
    at org.apache.catalina.core.ApplicationFilterChain.doFilter(ApplicationFilterChain.java:206)
    at org.springframework.orm.hibernate3.support.OpenSessionInViewFilter.doFilterInternal(OpenSessionInViewFilter.java:198)
    at org.springframework.web.filter.OncePerRequestFilter.doFilter(OncePerRequestFilter.java:76)
    at org.apache.catalina.core.ApplicationFilterChain.internalDoFilter(ApplicationFilterChain.java:235)
    at org.apache.catalina.core.ApplicationFilterChain.doFilter(ApplicationFilterChain.java:206)
    at org.apache.catalina.core.StandardWrapperValve.invoke(StandardWrapperValve.java:233)
    at org.apache.catalina.core.StandardContextValve.invoke(StandardContextValve.java:191)
    at org.apache.catalina.core.StandardHostValve.invoke(StandardHostValve.java:127)
    at org.apache.catalina.valves.ErrorReportValve.invoke(ErrorReportValve.java:102)
    at org.apache.catalina.core.StandardEngineValve.invoke(StandardEngineValve.java:109)
    at com.springsource.insight.collection.tcserver.request.HttpRequestOperationCollectionValve.traceNextValve(HttpRequestOperationCollectionValve.java:92)
    at com.springsource.insight.collection.tcserver.request.HttpRequestOperationCollectionValve.invoke(HttpRequestOperationCollectionValve.java:74)
    at org.apache.catalina.connector.CoyoteAdapter.service(CoyoteAdapter.java:298)
    at org.apache.coyote.http11.Http11Processor.process(Http11Processor.java:857)
    at org.apache.coyote.http11.Http11Protocol$Http11ConnectionHandler.process(Http11Protocol.java:588)
    at org.apache.tomcat.util.net.JIoEndpoint$SocketProcessor.run(JIoEndpoint.java:409)
    at java.util.concurrent.ThreadPoolExecutor$Worker.runTask(Unknown Source)
    at java.util.concurrent.ThreadPoolExecutor$Worker.run(Unknown Source)
    at java.lang.Thread.run(Unknown Source)
Caused by: java.lang.NullPointerException
    at org.pwsz.services.EventService.getAll(EventService.java:19)
    at sun.reflect.NativeMethodAccessorImpl.invoke0(Native Method)
    at sun.reflect.NativeMethodAccessorImpl.invoke(Unknown Source)
    at sun.reflect.DelegatingMethodAccessorImpl.invoke(Unknown Source)
    at java.lang.reflect.Method.invoke(Unknown Source)
    at flex.messaging.services.remoting.adapters.JavaAdapter.invoke(JavaAdapter.java:418)
    ... 47 more

那么问题仍然没有解决，有人可以帮忙吗？提前感谢最终

---

我解决了我替换 blazeds services-config.xml 的问题：

<services-config>
    <services>
        <service id="remoting-service" class="flex.messaging.services.RemotingService">
            <default-channels>
                <channel ref="my-amf" />
            </default-channels>

            <adapters>
                <adapter-definition id="java-object"
                    class="flex.messaging.services.remoting.adapters.JavaAdapter"
                    default="true" />
            </adapters>

            <destination id="myService" channels="my-amf">
                <properties>
                    <source>org.abc.services.EventService</source>
                </properties>
            </destination>
        </service>
    </services>

    <channels>
        <channel-definition id="my-amf"
            class="mx.messaging.channels.AMFChannel">
            <endpoint
                url="http://{server.name}:{server.port}/{context.root}/messagebroker/amf"
                class="flex.messaging.endpoints.AMFEndpoint" />
        </channel-definition>
    </channels>

</services-config>

通过 org.abc.services.EventService 中的注释

@RemotingDestination(value="myService",channels={"my-amf"})

我也尝试了 appContext.xml 中的定义，它也有效：

<flex:remoting-destination destination-id="myService"  ref="eventService"/>

但我仍然不明白为什么配置services-config 不起作用，主要问题是对于每个 AMF 请求，Spring 都会生成新的 eventService 对象（没有自动装配 dao），请注意，不需要 Dao 的功能可以正常工作。

---

我的 web.xml

<context-param>
    <param-name>log4jConfigLocation</param-name>
    <param-value>classpath:log4j.properties</param-value>
</context-param>

<listener>
    <listener-class>org.springframework.web.util.Log4jConfigListener</listener-class>
</listener>

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

<servlet>
    <servlet-name>rws</servlet-name>
    <servlet-class>org.springframework.web.servlet.DispatcherServlet</servlet-class>
    <load-on-startup>1</load-on-startup>
</servlet>

<servlet-mapping>
    <servlet-name>rws</servlet-name>
    <url-pattern>/</url-pattern>
</servlet-mapping>

<welcome-file-list>
    <welcome-file>
        index.jsp
    </welcome-file>
</welcome-file-list>

Answer 1

如果您不使用注释@RemotingDestination，或者如果您没有在appContext.xml（或Spring使用的另一个xml）中声明组件，Spring框架将无法管理您的bean（又名inhect属性等），这就是为什么DAO 对象为空。对于“经典”BlazeDS 配置文件中声明的所有组件都是如此。