间歇性错误org.hibernate.PersistentObjectException:传递给persist的分离实体

Question

我收到异常org.hibernate.PersistentObjectException:传递给persist的分离实体.从本论坛和其他地方的众多帖子中,我了解到这种情况发生在两种情况下(不考虑One-One注释等),

1. 超出范围的交易存在问题
2. 将id设置为应自动生成的位置.

我看到这些都没有发生在我的代码中.我无法重现错误,因为我没有最初触发它的数据.在其他数据上,它运行得很好.我在下面提供了一个SCCE:

public class MyProcessor {
    private MyImportEJB myEJB = MyImportEJB.getInstance();
    private List<MyClass> saveQueue = new ArrayList<MyClass>();
    public void process() {
        List<X> rawData = getListOfX();
        for(X x:rawData) {
             processX();
         }
         saveFoos(saveQueue);   
     }

     public void saveOrUpdateFoos(List<Foo> foos) {

        for(MyClass foo:foos) {
              MyClass existingFoo = myEJB.getFoosForWidAndDates(foo.getWid(), foo.getEffBeginDt(),foo.getEffEndDt());
              if(existingFoo == null) saveQueue.add(foo);
              else {
                   existingFoo.updateIfDifferent(foo);
                   saveQueue.add(existingFoo);
              }
         }

         if(saveQueue.size() > 5000) {
             myEJB.saveObjects(saveQueue);
             saveQueue.clear();
         }
     }

     public void processX() {
          ArrayList<MyClass> foos = new ArrayList<MyClass>();

          if(x.reportPeriod != null && x.gravity != null){
              MyClass foo = new MyClass();
              foo.setId(null);
              foo.setWId(x.getWid());
              foo.setEffBeginDt(x.reportPeriod);
              foo.setEffEndDt(addOneMonth(x.reportPeriod));
              foo.setGravity(x.gravity);

              foos.add(foo);
          }
          saveOrUpdateFoos(foos);

     }
 }

MyImportEJB.java:

@Stateless
@EJB(name = "MyImportEJB", beanInterface = MyImportEJB.class)
@TransactionAttribute(TransactionAttributeType.SUPPORTS)
@PermitAll
public class MyImportEJB{
    @Override
    @TransactionAttribute(TransactionAttributeType.REQUIRED)
    public void saveObjects(List<? extends P> mappedObjects) 
    {
        for (P mappedObject : mappedObjects)
        {
            this.saveObject(mappedObject);
        }
    }


    @Override
    @TransactionAttribute(TransactionAttributeType.REQUIRED)
    public void saveObject(P mappedObject) 
    {
        EntityManager entityManager = this.getEntityManager();

        Object identifier = this.getEntityManagerFactory().getPersistenceUnitUtil().getIdentifier(mappedObject);
        if (identifier != null) {
            Object existingObject = entityManager.find(mappedObject.getClass(), identifier);

            if (existingObject != null) {
                entityManager.merge(mappedObject);
                return;
            }
         }

         entityManager.persist(mappedObject);
    }

    public MyClass getFoosForWidAndDates(Integer wid, Calendar effBeginDt, Calendar effEndDt) {
         try {
            return (MyClass)((this.entityManager
        .createQuery("select M from MyClass M where wid = :wid and effBeginDt = :effBeginDt and effEndDt = :effEndDt ", MyClass.class)
        .setParameter("wid",wid)
        .setParameter("effBeginDt", effBeginDt)
        .setParameter("effEndDt", effEndDt)).getSingleResult());
         } catch(NoResultException | NonUniqueResultException e) {
            return null;
        }
    }
 }

MyClass.java

public MyClass{

      @Id
      @GeneratedValue(strategy=GenerationType.IDENTITY)
      @Column(name = "Id")
      private Integer id;

      @Column(name = "wid")
      private Integer wId;

      @Column(name = "eff_begin_dt")
      private Calendar effBeginDt;

      @Column(name = "eff_end_dt")
      private Calendar effEndDt;

      @Column(name = "gravity")
      private Double gravity;

      private Integer dataDownloadId;

      public void updateIfDifferent(MyClass other) {
          if(other.gravity != null && other.gravity != this.gravity) this.gravity = other.gravity;
          //same for effBeginDt andeffEndDt

      }

 }

persistence.xml中

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

 <persistence xmlns="http://java.sun.com/xml/ns/persistence"
xmlns:xsi="http://www.w3.org/2001/XMLSchema-instance"
xsi:schemaLocation="http://java.sun.com/xml/ns/persistence
http://java.sun.com/xml/ns/persistence/persistence_2_0.xsd"
version="2.0">
    <persistence-unit name="ProdData">
        <description>ProdData Database Persistence Unit</description>
        <provider>org.hibernate.ejb.HibernatePersistence</provider>
        <jta-data-source>java:jboss/ProdDataJNDI</jta-data-source>
        <class>path.to.MyClass</class>
        <class>path.to.X</class>
        <exclude-unlisted-classes>true</exclude-unlisted-classes>

        <properties>
            <property name="hibernate.show_sql" value="false" />
         </properties>
    </persistence-unit>
 </persistence>

调用entityManager.persist(mappedObject)< - MyImportEJB.saveObject <-MyImportEJB.saveObjects时抛出异常.我没有行号

我尝试编写一个示例程序,从数据库中获取一个existingFoo对象,更新并保存它,因为这是最可能的错误来源.但我无法重现错误.请帮忙.

编辑:以下是getListofX()的详细信息

来自MyProcessor.java:

public List<X> getListOfX() {
    return myImportEJB.getUnprocessedIds(X.class, 30495);
}

从文件MyImportEJB.java:

@TransactionAttribute(TransactionAttributeType.SUPPORTS)
public List<Integer> getUnprocessedIds(Class<? extends ProductionRawData> clazz, Integer dataDownloadId) {
    String canonicalName = clazz.getCanonicalName();

    String queryStr = "select id from " + canonicalName + " where datadownloadId = :dataDownloadId and isProcessed != 1";

    TypedQuery<Integer> query = this.entityManager.createQuery(queryStr, Integer.class)
        .setParameter("dataDownloadId", dataDownloadId);
    try {
        return query.getResultList();
    } catch(NoResultException nre) {
         return new ArrayList<T>();
    }
}

编辑:还添加了getFoosForWidAndDates()的详细信息.有人告诉我,在将新Foo的id添加到保存队列之前,我将其设置为null.我想知道是否有可能将Hibernate的"引擎盖"设置为不可接受的值

Answer 1

我再次在生产服务器上运行代码，并在分离实体异常之前收到 TransactionRollbackException。我认为这可能是我观察到的异常的实际原因。

由于我试图保存大量对象，事务超时并被回滚，这导致 Foo 对象分离。不知何故，TransactionRollbackException 第一次没有出现在日志中，可能是因为它恰好发生在世界标准时间上午 12:00。为了支持这一理论，在我将批量大小减少到 ~1000 后，程序到目前为止还没有崩溃

对于那些感兴趣的人来说， TransactionRollbackException 确实会导致实体分离：entityManager.getTransaction().rollback() 分离实体？

发生这种情况时有多种方法可以处理，但为了简单起见，我选择不实施它们