java - NullPointerEx 位于 org.hibernate.engine.StatefulPersistenceContext 第 1401 行

Question

我在 Hibernate 论坛上问这个问题已经一周了，没有得到任何答复 - https://forum.hibernate.org/viewtopic.php?f=1&t=1011634 。我真的被困在这里，希望能在这里得到帮助。我从 org.hibernate.engine.StatefulPersistenceContext 得到 NullPointerException。

我的 hibernate 依赖如下:组织 hibernate Hibernate实体管理器3.5.6-最终

异常堆栈如下:

        2011-07-04 07:06:38,691 DEBUG [http-8080-2] mobi.esca.mobile.remoting.HttpInvokerServiceExporter (HttpInvokerServiceExporter.java:168) - java.lang.NullPointerException
java.lang.NullPointerException
at org.hibernate.engine.StatefulPersistenceContext.replaceDelayedEntityIdentityInsertKeys(StatefulPersistenceContext.java:1401)
at org.hibernate.action.EntityIdentityInsertAction.postInsert(EntityIdentityInsertAction.java:117)
at org.hibernate.action.EntityIdentityInsertAction.execute(EntityIdentityInsertAction.java:89)
at org.hibernate.engine.ActionQueue.execute(ActionQueue.java:267)
at org.hibernate.engine.ActionQueue.executeActions(ActionQueue.java:259)
at org.hibernate.engine.ActionQueue.executeInserts(ActionQueue.java:169)
at org.hibernate.event.def.AbstractSaveEventListener.performSaveOrReplicate(AbstractSaveEventListener.java:287)
at org.hibernate.event.def.AbstractSaveEventListener.performSave(AbstractSaveEventListener.java:204)
at org.hibernate.event.def.AbstractSaveEventListener.saveWithGeneratedId(AbstractSaveEventListener.java:130)
at org.hibernate.ejb.event.EJB3PersistEventListener.saveWithGeneratedId(EJB3PersistEventListener.java:69)
at org.hibernate.event.def.DefaultPersistEventListener.entityIsTransient(DefaultPersistEventListener.java:179)
at org.hibernate.event.def.DefaultPersistEventListener.onPersist(DefaultPersistEventListener.java:135)
at org.hibernate.event.def.DefaultPersistEventListener.onPersist(DefaultPersistEventListener.java:61)
at org.hibernate.impl.SessionImpl.firePersist(SessionImpl.java:800)
at org.hibernate.impl.SessionImpl.persist(SessionImpl.java:774)
at org.hibernate.impl.SessionImpl.persist(SessionImpl.java:778)
at org.hibernate.ejb.AbstractEntityManagerImpl.persist(AbstractEntityManagerImpl.java:668)
at sun.reflect.NativeMethodAccessorImpl.invoke0(Native Method)
at sun.reflect.NativeMethodAccessorImpl.invoke(NativeMethodAccessorImpl.java:39)
at sun.reflect.DelegatingMethodAccessorImpl.invoke(DelegatingMethodAccessorImpl.java:25)
at java.lang.reflect.Method.invoke(Method.java:597)
at org.springframework.orm.jpa.ExtendedEntityManagerCreator$ExtendedEntityManagerInvocationHandler.invoke(ExtendedEntityManagerCreator.java:365)
at $Proxy138.persist(Unknown Source)
at sun.reflect.NativeMethodAccessorImpl.invoke0(Native Method)
at sun.reflect.NativeMethodAccessorImpl.invoke(NativeMethodAccessorImpl.java:39)
at sun.reflect.DelegatingMethodAccessorImpl.invoke(DelegatingMethodAccessorImpl.java:25)
at java.lang.reflect.Method.invoke(Method.java:597)
at org.springframework.orm.jpa.SharedEntityManagerCreator$SharedEntityManagerInvocationHandler.invoke(SharedEntityManagerCreator.java:240)
at $Proxy59.persist(Unknown Source)
at org.springframework.orm.jpa.JpaTemplate$5.doInJpa(JpaTemplate.java:264)
at org.springframework.orm.jpa.JpaTemplate.execute(JpaTemplate.java:183)
at org.springframework.orm.jpa.JpaTemplate.persist(JpaTemplate.java:262)
at mobi.esca.persistence.GenericJPARepository.persist(GenericJPARepository.java:153)
at mobi.esca.persistence.GenericJPARepository.persistAll(GenericJPARepository.java:161)
at mobi.esca.mars.application.UsageManager.logUsageStats(UsageManager.java:43)
at mobi.esca.mars.interfaces.mobile.EndUserController.reportStats(EndUserController.java:259)
at sun.reflect.NativeMethodAccessorImpl.invoke0(Native Method)
at sun.reflect.NativeMethodAccessorImpl.invoke(NativeMethodAccessorImpl.java:39)
at sun.reflect.DelegatingMethodAccessorImpl.invoke(DelegatingMethodAccessorImpl.java:25)
at java.lang.reflect.Method.invoke(Method.java:597)
at org.springframework.aop.support.AopUtils.invokeJoinpointUsingReflection(AopUtils.java:309)
at org.springframework.aop.framework.JdkDynamicAopProxy.invoke(JdkDynamicAopProxy.java:196)
at $Proxy137.reportStats(Unknown Source)
at sun.reflect.NativeMethodAccessorImpl.invoke0(Native Method)
at sun.reflect.NativeMethodAccessorImpl.invoke(NativeMethodAccessorImpl.java:39)
at sun.reflect.DelegatingMethodAccessorImpl.invoke(DelegatingMethodAccessorImpl.java:25)
at java.lang.reflect.Method.invoke(Method.java:597)
at mobi.esca.mobile.remoting.RemoteInvocationAdaptor.invoke(RemoteInvocationAdaptor.java:89)
at mobi.esca.mobile.remoting.RemoteInvocationAdaptor.proceed(RemoteInvocationAdaptor.java:54)
at mobi.esca.mobile.remoting.FilterChain.doFilter(FilterChain.java:59)
at mobi.esca.mobile.remoting.MethodInvocationRateFromUserProtection.doFilter(MethodInvocationRateFromUserProtection.java:56)
at mobi.esca.mobile.remoting.FilterChain.doFilter(FilterChain.java:56)
at mobi.esca.mobile.remoting.MethodInvocationRateFromIpProtection.doFilter(MethodInvocationRateFromIpProtection.java:57)
at mobi.esca.mobile.remoting.FilterChain.doFilter(FilterChain.java:56)
at mobi.esca.mars.interfaces.mobile.ClientVersionChecker.doFilter(ClientVersionChecker.java:41)
at mobi.esca.mobile.remoting.FilterChain.doFilter(FilterChain.java:56)
at mobi.esca.mobile.remoting.AuthenticationFilter.doFilter(AuthenticationFilter.java:37)
at mobi.esca.mobile.remoting.FilterChain.doFilter(FilterChain.java:56)
at mobi.esca.mobile.remoting.HttpInvokerServiceExporter.invokeAndCreateResult(HttpInvokerServiceExporter.java:201)
at mobi.esca.mobile.remoting.HttpInvokerServiceExporter.handleRequestInternal(HttpInvokerServiceExporter.java:128)
at mobi.esca.mobile.remoting.HttpInvokerServiceExporter.handleRequest(HttpInvokerServiceExporter.java:102)
at org.springframework.web.servlet.mvc.HttpRequestHandlerAdapter.handle(HttpRequestHandlerAdapter.java:49)
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:644)
at org.springframework.web.servlet.FrameworkServlet.doPost(FrameworkServlet.java:560)
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.web.filter.CharacterEncodingFilter.doFilterInternal(CharacterEncodingFilter.java:88)
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.springframework.orm.jpa.support.OpenEntityManagerInViewFilter.doFilterInternal(OpenEntityManagerInViewFilter.java:113)
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:219)
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 org.apache.catalina.connector.CoyoteAdapter.service(CoyoteAdapter.java:298)
at org.apache.coyote.http11.Http11Processor.process(Http11Processor.java:852)
at org.apache.coyote.http11.Http11Protocol$Http11ConnectionHandler.process(Http11Protocol.java:588)
at org.apache.tomcat.util.net.JIoEndpoint$Worker.run(JIoEndpoint.java:489)

我正在查看 StatefulPersistenceContext.java 文件的第 1401 行:

1396   public void replaceDelayedEntityIdentityInsertKeys(EntityKey oldKey, Serializable generatedId) {
1397      Object entity = entitiesByKey.remove( oldKey );
1398      EntityEntry oldEntry = ( EntityEntry ) entityEntries.remove( entity );
1399      parentsByChild.clear();
1400
1401      EntityKey newKey = new EntityKey( generatedId, oldEntry.getPersister(), getSession().getEntityMode() );
1402      addEntity( newKey, entity );

所以这里可能的空对象可能是oldEntry，对吗？谁能告诉我oldEntry什么时候可以变成空？我可以做什么来解决这个问题？

我们将非常感谢您的帮助。

非常感谢，程伟

<小时/>

嗨，莫，

感谢您的回复。现在，异常在我们系统中的各种方法中随机发生，我无法通过单元测试重新创建它。我将给出一个方法中最简单的代码。

@Controller
public class EndUserController implements EndUserService, InvocationContextRequired
{
    @Override
    public void reportStats(UsageStatsDTO usageStatsDTO) throws ClientVersionOutOfDateException
    {
        log.debug("enter UsageReportController.reportStats()");
        UsageStats usageStats = usageStatsDTO.asUsageStats(getEndUser());
        usageManager.logUsageStats(usageStats);
        if(usageStats.hasAppStartEvent())
        {
            endUserManager.updateClientVersion(getEndUser(), getClientVersion());
        }
        log.debug("exit UsageReportController.reportStats()");
    }
    ......
}

@Service
public class UsageManager
{
    @Autowired
    private CallEventRepository callEventRepository;
    @Autowired
    private AppStartEventRepository appStartEventRepository;
    @Autowired
    private InviteEventRepository inviteEventRepository;

    @Transactional
    public void logUsageStats(UsageStats usageStats)
    {
        if (usageStats.hasCallEvent())
        {
            callEventRepository.persistAll(usageStats.getCallEvents());
        }
        if (usageStats.hasAppStartEvent())
        {
            appStartEventRepository.persistAll(usageStats.getAppStartEvents());
        }
        if (usageStats.hasInviteEvent())
        {
            inviteEventRepository.persistAll(usageStats.getInviteEvents());
        }
    }
    ......
}

public class GenericJPARepository<T, ID extends Serializable>
    implements GenericRepository<T, ID>
{
    @Override
    public T persist(T entity)
    {
        getJpaTemplate().persist(entity);
        return entity;
    }
    @Override
    public void persistAll(Collection<T> entities)
    {
        for(T entity : entities)
        {
            persist(entity);
        }
    }
    ......
}

所有 RepositoryImpl 类都是 GenericJPARepository 的子类(CallEventRepository、AppStartEventRepository、InviteEventRepository)。

非常感谢，程伟

<小时/>

问题可能是由我分离实体引起的吗？ endUserRepository.detach(detachedEndUser);但要持久化的对象UsageStats并没有引用detatchedEndUser。

<小时/>

感谢 Moe 和 Maurice，感谢您的帮助。我终于找到问题所在了。以下代码导致了问题:

EndUser toBePersistedEndUser = endUserRepository.persist(new EndUser(remoteEndUser));
endUserRepository.detach(toBePersistedEndUser );
return toBePersistedEndUser;

另外，我想我在这里揭示了一个 hibernate 错误。

问题已解决，非常感谢，程伟

Answer 1

好吧，要么 oldEntry 为 null，要么 getSession() 返回 null。显然，如果entityEntries不包含从entitiesByKey中删除的条目，oldEntry将为null。如果 EntityEntry 的 equals() 方法未正确实现，也可能会发生这种情况。