java.lang.IllegalStateException：使用 AOP 的键 [org.hibernate.impl.SessionFactoryImpl] 没有值

Question

每次使用 Hibernate 更新实体时都会出错。 这是我的故事：

我有一个带有 @Transactional 注释的服务，并且正在调用 DAO.update 方法。

@Service
@Transactional
public class FooServiceImpl implements FooService {
    @Inject
    private FooDAO fooDAO;

    @Override
    public Foo update(Foo foo) {
       return fooDAO.update(foo);
    }

    @Override
    public Foo find(int fooId) {
       return fooDAO.findById(fooId);
    }
}

我有一个 AOP，它捕获 DAO.update 以便进行一些操作。

@Aspect
@Order(2)
@Component
public class FooTackerAspect {
   @Inject
   private FooService fooService;

   @Inject
   private SessionFactoryManager sessionFactoryManager;

   @Pointcut("execution(* com.foo.bar.FooService.update(..))")
   public void methodToTrack() {}

   @Around("methodToTrack")
   public Object track(final ProceedingJoinPoint joinPoint) throws Throwable {
      int fooId = fetchIdFromJoinPoint(joinPoint);
      Foo foo = fooService.find(fooId);

      // Do some operations

      // I close the session in order to avoid the exception
      // org.hibernate.NonUniqueObjectException: a different object with
      // the same identifier value was already associated with the session
      sessionFactoryManager.getSessionFactory(DataSource.FOO)
          .getCurrentSession().close();

      Object retVal = joinPoint.proceed();
      return retVal;
   }
}

但是，在更新实体 (fooDAO.update(foo)) 后，我收到以下错误：

2056953 [http-bio-8080-exec-4] ERROR o.s.t.s.TransactionSynchronizationUtils - TransactionSynchronization.beforeCompletion threw exception 
java.lang.IllegalStateException: No value for key [org.hibernate.impl.SessionFactoryImpl@762d6271] bound to thread [http-bio-8080-exec-4]
    at org.springframework.transaction.support.TransactionSynchronizationManager.unbindResource(TransactionSynchronizationManager.java:209) ~[spring-tx-3.2.4.RELEASE.jar:3.2.4.RELEASE]
    at org.springframework.orm.hibernate3.SpringSessionSynchronization.beforeCompletion(SpringSessionSynchronization.java:193) ~[spring-orm-3.2.4.RELEASE.jar:3.2.4.RELEASE]
    at org.springframework.transaction.support.TransactionSynchronizationUtils.triggerBeforeCompletion(TransactionSynchronizationUtils.java:106) ~[spring-tx-3.2.4.RELEASE.jar:3.2.4.RELEASE]
    at org.springframework.transaction.support.AbstractPlatformTransactionManager.triggerBeforeCompletion(AbstractPlatformTransactionManager.java:938) [spring-tx-3.2.4.RELEASE.jar:3.2.4.RELEASE]
    at org.springframework.transaction.support.AbstractPlatformTransactionManager.processCommit(AbstractPlatformTransactionManager.java:739) [spring-tx-3.2.4.RELEASE.jar:3.2.4.RELEASE]
    at org.springframework.transaction.support.AbstractPlatformTransactionManager.commit(AbstractPlatformTransactionManager.java:724) [spring-tx-3.2.4.RELEASE.jar:3.2.4.RELEASE]
    at org.springframework.transaction.interceptor.TransactionAspectSupport.commitTransactionAfterReturning(TransactionAspectSupport.java:475) [spring-tx-3.2.4.RELEASE.jar:3.2.4.RELEASE]
    at org.springframework.transaction.interceptor.TransactionAspectSupport.invokeWithinTransaction(TransactionAspectSupport.java:270) [spring-tx-3.2.4.RELEASE.jar:3.2.4.RELEASE]
    at org.springframework.transaction.interceptor.TransactionInterceptor.invoke(TransactionInterceptor.java:94) [spring-tx-3.2.4.RELEASE.jar:3.2.4.RELEASE]
    at org.springframework.aop.framework.ReflectiveMethodInvocation.proceed(ReflectiveMethodInvocation.java:172) [spring-aop-3.2.4.RELEASE.jar:3.2.4.RELEASE]
    at org.springframework.aop.framework.JdkDynamicAopProxy.invoke(JdkDynamicAopProxy.java:204) [spring-aop-3.2.4.RELEASE.jar:3.2.4.RELEASE]
    at com.sun.proxy.$Proxy112.update(Unknown Source) [$Proxy112.class:na]

此错误未阻塞（更新仍在进行）。但我想纠正这个错误。 你知道我该怎么做吗？

我认为错误来自我关闭会话的事实。但我必须关闭它才能更新实体。

Answer 1

正如@kriegaex 所说，问题在于我使用同一个会话来执行 find 和 update 操作。

鉴于该信息，我使用以下解决方法（可行）：我使用两个单独的会话，一个用于 find，另一个用于 update。

@Repository
public class FooDAOImpl implements FooDAO {
    private FooHibernateDaoSupport hibernateDaoSupport;

    public FooDAOImpl() {
        // Init DaoSupport
    }

    @Override
    public Foo findById(final Serializable fooId) {
        StatelessSession session = hibernateDaoSupport.getSessionFactory().openStatelessSession();
        Foo foo = (Foo) session.get(Foo.class, fooId);
        session.close;
        return foo;
    }

    @Override
    public Foo update(Foo foo) {
        getHibernateTemplate().update(entity);
        return entity;
    }
}

有了这个解决方案，我的建议代码中不再需要关闭会话了。

NB：我正在打开一个无状态会话，因为在我的项目中 FooService.update 还调用 FooService.find 以设置一些属性，所以我不想在我的建议代码中进行修改。