Question

我需要在实体监听器中持久保存新的实体对象，但它只在第一次通话时工作正常。

请参阅以下代码：

    public class SomeListener{
         @PreUpdate
         public void preUpdate(SomeEntity o){
             EntityManager em= EntityManagerUtils.getEntityManager();
             em.persist(new OtherObj());
         }
    }
    public class EntityManagerUtils {
        protected static EntityManager getEntityManager() throws Exception {
            Object sb = new InitialContext().lookup(JNDI_EntityLisenterSB);
            Method method = sb.getClass().getMethod("getEntityManager");
            return (EntityManager) method.invoke(sb);
    }}

在第二次通话后低于错误日志：

ARJUNA012125: TwoPhaseCoordinator.beforeCompletion - failed for SynchronizationImple< 0:ffffac19b619:7c4a5bbb:56cfb972:19e, org.eclipse.persistence.transaction.JTASynchronizationListener@7bece143 >: java.lang.NullPointerException

...

javax.ejb.EJBTransactionRolledbackException: Transaction rolled back

...

Caused by: javax.transaction.RollbackException: ARJUNA016053: Could not commit transaction.

但新对象已保存到数据库

at com.arjuna.ats.internal.jta.transaction.arjunacore.TransactionImple.commitAndDisassociate(TransactionImple.java:1177)

at com.arjuna.ats.internal.jta.transaction.arjunacore.BaseTransaction.commit(BaseTransaction.java:126)
at com.arjuna.ats.jbossatx.BaseTransactionManagerDelegate.commit(BaseTransactionManagerDelegate.java:75)
at org.jboss.as.ejb3.tx.CMTTxInterceptor.endTransaction(CMTTxInterceptor.java:92) [jboss-as-ejb3-7.3.0.Final-redhat-14.jar:7.3.0.Final-redhat-14]
... 94 more
Caused by: java.lang.NullPointerException
    at org.eclipse.persistence.internal.queries.DatabaseQueryMechanism.updateObjectForWriteWithChangeSet(DatabaseQueryMechanism.java:1005)

任何人都可以提供帮助吗？非常感谢。

工作环境

jboss eap6.2
Oracle11g的
eclipselink 2.4.1

Answer 1

提交实体后，该实体将分离。通过第一次调用persist()执行提交，导致您的实体分离。您可以做的是在再次呼叫另一个persist()之前再次开始交易。

getTransaction().begin();

如果实体监听器中的实体管理器不能调用persist

1 个答案: