Spring+Hibernate+Blazeds null error when using Flex client

Question

My problem is simple, when i run methods from my EventService from standalone app (by using ClassPathXmlApplicationContext in main() ) everything works fine.

@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";
    }
}

When i run on tomcat (built-in server on STS), container starts correctly but when i send request (Flex app thru AMF) to getAll() method or getAllContainsResource(int) *NullPointerException* comes up. It shows that eventDao is null. I don't know what can be the reason so please help. Here is my 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>

XML for standalone application is same, ofcourse without

<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 connection works fine, i can request getName using Flex Remote Object but sending request for the other two generates null exception.

Regards

I checked problem in WebApp (using spring mvc) and everything works fine. I found that problem generates Hibernate which return null sessionFactory for DAOs (they are @autowired) when request comes from Flex (using AMF protocol).

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

So problem is still not solved, can anybody help ? thanks in advance

Finnaly i solved the problem i replaced blazeds services-config.xml :

<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>

by annotation in org.abc.services.EventService

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

i tried also definition in appContext.xml and it works too :

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

but i still don't get why configuration in services-config didn't work, the main problem was that for every AMF request Spring was generating new eventService object (without autowiring dao), notice that functions that don't needed Dao worked fine.

my 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>

is there a web.xml that you would like to share? or wherever you're loading your spring bean config file from. — Saket
@Saket web.xml is pretty standard i partly-solved problem and updated my post. Thanks for your concern — Kohegen

Cornel Creanga Cornel Creanga · Accepted Answer · 2011-09-26T17:25:34

If you do not use the annotation @RemotingDestination or if you don't declare the component in appContext.xml (or another xml used by Spring) the Spring framework will not be able to manage your bean (aka inhect properties etc), that's why the DAO object is null. That's true for all the components declared in the "classic" BlazeDS config files.

Spring+Hibernate+Blazeds null error when using Flex client

1 Answers