java - Hibernate collection is not associated with any session

Question

I have found several questions and answers with regard to this issue on SO, but they all seem to cover one major cause of the problem: fetching a collection outside of a transaction or within another transaction. But in my case, I am fetching within the same transaction when fetching a parent object and collection.

@Service
@Transactional
public class IntegrationServiceImpl implements IntegrationService {
@Override
    public Integration getIntegrationByIdFetchBackendParameters(Long integrationId) {
        Integration integration = integrationDao.get(integrationId);
        //not all integrations have to have backend.
        if (integration.getBackend() != null) {
            Hibernate.initialize(integration.getBackend().getBackendParameters());
        }
        return integration;
    }
...

But when it comes to Hibernate.initialize this branch in org.hibernate.collection.internal.AbstractPersistentCollection is executed

if ( session == null ) {
                throw new HibernateException( "collection is not associated with any session" );
            }

I cant see why session is null. Would someone explain this and suggest a solution?

EDIT 1 - Full stack trace

org.hibernate.HibernateException: collection is not associated with any session
        at org.hibernate.collection.internal.AbstractPersistentCollection.forceInitialization(AbstractPersistentCollection.java:676)
        at org.hibernate.Hibernate.initialize(Hibernate.java:77)
        at com.dhl.finFw.service.IntegrationServiceImpl.getIntegrationByIdFetchBackendParameters(IntegrationServiceImpl.java:169)
        at com.dhl.finFw.web.integration.IntegrationOverviewManagedBean.loadIntegration(IntegrationOverviewManagedBean.java:59)
        at com.dhl.finFw.web.integration.AbstractIntegrationManagedBean.initCommonFields(AbstractIntegrationManagedBean.java:69)
        at sun.reflect.NativeMethodAccessorImpl.invoke0(Native Method)
        at sun.reflect.NativeMethodAccessorImpl.invoke(NativeMethodAccessorImpl.java:57)
        at sun.reflect.DelegatingMethodAccessorImpl.invoke(DelegatingMethodAccessorImpl.java:43)
        at java.lang.reflect.Method.invoke(Method.java:606)
        at org.springframework.beans.factory.annotation.InitDestroyAnnotationBeanPostProcessor$LifecycleElement.invoke(InitDestroyAnnotationBeanPostProcessor.java:344)
        at org.springframework.beans.factory.annotation.InitDestroyAnnotationBeanPostProcessor$LifecycleMetadata.invokeInitMethods(InitDestroyAnnotationBeanPostProcessor.java:295)
        at org.springframework.beans.factory.annotation.InitDestroyAnnotationBeanPostProcessor.postProcessBeforeInitialization(InitDestroyAnnotationBeanPostProcessor.java:130)
        at org.springframework.beans.factory.support.AbstractAutowireCapableBeanFactory.applyBeanPostProcessorsBeforeInitialization(AbstractAutowireCapableBeanFactory.java:399)
        at org.springframework.beans.factory.support.AbstractAutowireCapableBeanFactory.initializeBean(AbstractAutowireCapableBeanFactory.java:1481)
        at org.springframework.beans.factory.support.AbstractAutowireCapableBeanFactory.doCreateBean(AbstractAutowireCapableBeanFactory.java:524)
        at org.springframework.beans.factory.support.AbstractAutowireCapableBeanFactory.createBean(AbstractAutowireCapableBeanFactory.java:461)
        at org.springframework.beans.factory.support.AbstractBeanFactory$2.getObject(AbstractBeanFactory.java:333)
        at com.dhl.finFw.spring.scope.ViewScope.get(ViewScope.java:30)
        at org.springframework.beans.factory.support.AbstractBeanFactory.doGetBean(AbstractBeanFactory.java:329)
        at org.springframework.beans.factory.support.AbstractBeanFactory.getBean(AbstractBeanFactory.java:194)
        at org.springframework.context.support.AbstractApplicationContext.getBean(AbstractApplicationContext.java:1117)
        at org.springframework.beans.factory.access.el.SpringBeanELResolver.getValue(SpringBeanELResolver.java:56)
        at com.sun.faces.el.DemuxCompositeELResolver._getValue(DemuxCompositeELResolver.java:176)
        at com.sun.faces.el.DemuxCompositeELResolver.getValue(DemuxCompositeELResolver.java:203)
        at org.apache.el.parser.AstIdentifier.getValue(AstIdentifier.java:72)
        at org.apache.el.ValueExpressionImpl.getValue(ValueExpressionImpl.java:185)
        at com.sun.faces.facelets.el.TagValueExpression.getValue(TagValueExpression.java:109)
        at org.apache.el.parser.AstIdentifier.getValue(AstIdentifier.java:68)
        at org.apache.el.parser.AstValue.getValue(AstValue.java:161)
        at org.apache.el.ValueExpressionImpl.getValue(ValueExpressionImpl.java:185)
        at com.sun.faces.facelets.el.TagValueExpression.getValue(TagValueExpression.java:109)
        at com.sun.faces.facelets.tag.jstl.core.ForEachHandler.apply(ForEachHandler.java:161)
        at javax.faces.view.facelets.CompositeFaceletHandler.apply(CompositeFaceletHandler.java:95)
        at com.sun.faces.facelets.tag.ui.CompositionHandler.apply(CompositionHandler.java:166)
        at com.sun.faces.facelets.compiler.NamespaceHandler.apply(NamespaceHandler.java:93)
        at com.sun.faces.facelets.compiler.EncodingHandler.apply(EncodingHandler.java:87)
        at com.sun.faces.facelets.impl.DefaultFacelet.include(DefaultFacelet.java:320)
        at com.sun.faces.facelets.impl.DefaultFacelet.include(DefaultFacelet.java:379)
        at com.sun.faces.facelets.impl.DefaultFacelet.include(DefaultFacelet.java:358)
        at com.sun.faces.facelets.impl.DefaultFaceletContext.includeFacelet(DefaultFaceletContext.java:199)
        at com.sun.faces.facelets.tag.ui.IncludeHandler.apply(IncludeHandler.java:120)
        at javax.faces.view.facelets.CompositeFaceletHandler.apply(CompositeFaceletHandler.java:95)
        at com.sun.faces.facelets.tag.ui.DefineHandler.applyDefinition(DefineHandler.java:106)
        at com.sun.faces.facelets.tag.ui.CompositionHandler.apply(CompositionHandler.java:178)
        at com.sun.faces.facelets.impl.DefaultFaceletContext$TemplateManager.apply(DefaultFaceletContext.java:395)
        at com.sun.faces.facelets.impl.DefaultFaceletContext.includeDefinition(DefaultFaceletContext.java:366)
        at com.sun.faces.facelets.tag.ui.InsertHandler.apply(InsertHandler.java:111)
        at javax.faces.view.facelets.CompositeFaceletHandler.apply(CompositeFaceletHandler.java:95)
        at javax.faces.view.facelets.DelegatingMetaTagHandler.applyNextHandler(DelegatingMetaTagHandler.java:137)
        at com.sun.faces.facelets.tag.jsf.ComponentTagHandlerDelegateImpl.apply(ComponentTagHandlerDelegateImpl.java:187)
        at javax.faces.view.facelets.DelegatingMetaTagHandler.apply(DelegatingMetaTagHandler.java:120)
        at javax.faces.view.facelets.CompositeFaceletHandler.apply(CompositeFaceletHandler.java:95)
        at com.sun.faces.facelets.tag.jsf.core.ViewHandler.apply(ViewHandler.java:179)
        at javax.faces.view.facelets.CompositeFaceletHandler.apply(CompositeFaceletHandler.java:95)
        at com.sun.faces.facelets.compiler.NamespaceHandler.apply(NamespaceHandler.java:93)
        at com.sun.faces.facelets.compiler.EncodingHandler.apply(EncodingHandler.java:87)
        at com.sun.faces.facelets.impl.DefaultFacelet.include(DefaultFacelet.java:320)
        at com.sun.faces.facelets.impl.DefaultFacelet.include(DefaultFacelet.java:379)
        at com.sun.faces.facelets.impl.DefaultFacelet.include(DefaultFacelet.java:358)
        at com.sun.faces.facelets.impl.DefaultFaceletContext.includeFacelet(DefaultFaceletContext.java:199)
        at com.sun.faces.facelets.tag.ui.CompositionHandler.apply(CompositionHandler.java:155)
        at com.sun.faces.facelets.compiler.NamespaceHandler.apply(NamespaceHandler.java:93)
        at com.sun.faces.facelets.compiler.EncodingHandler.apply(EncodingHandler.java:87)
        at com.sun.faces.facelets.impl.DefaultFacelet.apply(DefaultFacelet.java:164)
        at com.sun.faces.application.view.FaceletViewHandlingStrategy.buildView(FaceletViewHandlingStrategy.java:870)
        at com.sun.faces.lifecycle.RenderResponsePhase.execute(RenderResponsePhase.java:99)
        at com.sun.faces.lifecycle.Phase.doPhase(Phase.java:101)
        at com.sun.faces.lifecycle.LifecycleImpl.render(LifecycleImpl.java:139)
        at javax.faces.webapp.FacesServlet.service(FacesServlet.java:594)
        at org.apache.catalina.core.ApplicationFilterChain.internalDoFilter(ApplicationFilterChain.java:305)
        at org.apache.catalina.core.ApplicationFilterChain.doFilter(ApplicationFilterChain.java:210)
        at org.primefaces.webapp.filter.FileUploadFilter.doFilter(FileUploadFilter.java:79)
        at org.apache.catalina.core.ApplicationFilterChain.internalDoFilter(ApplicationFilterChain.java:243)
        at org.apache.catalina.core.ApplicationFilterChain.doFilter(ApplicationFilterChain.java:210)
        at com.dhl.finFw.web.filter.FileNotFoundFilter.doFilter(FileNotFoundFilter.java:40)
        at com.dhl.finFw.web.filter.FileNotFoundFilter.doFilter(FileNotFoundFilter.java:35)
        at org.apache.catalina.core.ApplicationFilterChain.internalDoFilter(ApplicationFilterChain.java:243)
        at org.apache.catalina.core.ApplicationFilterChain.doFilter(ApplicationFilterChain.java:210)
        at org.springframework.web.filter.CharacterEncodingFilter.doFilterInternal(CharacterEncodingFilter.java:88)
        at org.springframework.web.filter.OncePerRequestFilter.doFilter(OncePerRequestFilter.java:107)
        at org.apache.catalina.core.ApplicationFilterChain.internalDoFilter(ApplicationFilterChain.java:243)
        at org.apache.catalina.core.ApplicationFilterChain.doFilter(ApplicationFilterChain.java:210)
        at org.springframework.security.web.FilterChainProxy$VirtualFilterChain.doFilter(FilterChainProxy.java:330)
        at org.springframework.security.web.access.intercept.FilterSecurityInterceptor.invoke(FilterSecurityInterceptor.java:118)
        at org.springframework.security.web.access.intercept.FilterSecurityInterceptor.doFilter(FilterSecurityInterceptor.java:84)
        at org.springframework.security.web.FilterChainProxy$VirtualFilterChain.doFilter(FilterChainProxy.java:342)
        at org.springframework.security.web.access.ExceptionTranslationFilter.doFilter(ExceptionTranslationFilter.java:113)
        at org.springframework.security.web.FilterChainProxy$VirtualFilterChain.doFilter(FilterChainProxy.java:342)
        at org.springframework.security.web.session.SessionManagementFilter.doFilter(SessionManagementFilter.java:64)
        at org.springframework.security.web.FilterChainProxy$VirtualFilterChain.doFilter(FilterChainProxy.java:342)
        at org.springframework.security.web.session.SessionManagementFilter.doFilter(SessionManagementFilter.java:103)
        at org.springframework.security.web.FilterChainProxy$VirtualFilterChain.doFilter(FilterChainProxy.java:342)
        at org.springframework.security.web.authentication.AnonymousAuthenticationFilter.doFilter(AnonymousAuthenticationFilter.java:113)
        at org.springframework.security.web.FilterChainProxy$VirtualFilterChain.doFilter(FilterChainProxy.java:342)
        at org.springframework.security.web.servletapi.SecurityContextHolderAwareRequestFilter.doFilter(SecurityContextHolderAwareRequestFilter.java:54)
        at org.springframework.security.web.FilterChainProxy$VirtualFilterChain.doFilter(FilterChainProxy.java:342)
        at org.springframework.security.web.savedrequest.RequestCacheAwareFilter.doFilter(RequestCacheAwareFilter.java:45)
        at org.springframework.security.web.FilterChainProxy$VirtualFilterChain.doFilter(FilterChainProxy.java:342)
        at org.springframework.security.web.authentication.AbstractAuthenticationProcess

Answer 1

I fixed this issue just putting @Transactional at top of the method.