EntityManager throws OptimisticLockException when trying to delete a locked object in one transaction
Here is my code:
EntityManager em = JPAUtil.createEntityManager();
try {
EntityTransaction tx = em.getTransaction();
try {
//do some stuff here
tx.begin();
List es = em.createNamedQuery("getMyEntities", MyEntity.class).getResultList();
for (MyEntity e : es) {
em.lock(e, LockModeType.OPTIMISTIC);
}
if (es.size() != 0) {
em.remove(es.get(0));
}
tx.commit
} finally {
if (tx.isActive()) {
tx.rollback();
}
}
} finally {
em.close();
}
When I execute this code I get:
...
..........
Caused by: javax.persistence.OptimisticLockException: Newer version [null] of entity [[MyEntity#63]] found in database
at org.hibernate.ejb.AbstractEntityManagerImpl.wrapLockException(AbstractEntityManagerImpl.java:1427)
at org.hibernate.ejb.AbstractEntityManagerImpl.convert(AbstractEntityManagerImpl.java:1324)
at org.hibernate.ejb.AbstractEntityManagerImpl.convert(AbstractEntityManagerImpl.java:1300)
at org.hibernate.ejb.TransactionImpl.commit(TransactionImpl.java:80)
... 23 more
Can someone explain to me why this is?
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I assume that you added the @Version
-annotated column after you already have some records in the database, so some null values were generated for the already existing records. Now hibernate cannot compare versions.
I would try to set the version column to 1 for all objects with a zero version.
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I think this error is due to the fact that I am trying to delete a record that has a lock on it. When trying to delete this line, install the version null
, but the version in the database is still the same. It seems that the hibernate kernel perceives the value null
as unreliable for this kind of operation.
If I need to perform such an operation, I must first lock the lock on this entity.
Anyone who knows better about this should clarify this issue.
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