Code [0] fails with [1]. I am just trying to pesimistically lock an entity in the same transaction where I created it.
Cause is that
1) Entity has SEQUENCE id generator, Hibernate doesn't flush before the find() nor before the lock().
2) With PESSIMISTIC_WRITE Hibernate has to issue SELECT FOR UPDATE.
Because entity is not inserted at the time of the SELECT FOR UPDATE, the find/lock fails....
Currently I workaround this by flushing before acquiring the pessimistic lock.
[0]
{ noformat code:java }
package cz.nguyen;
import java.sql.SQLException;
import javax.persistence.*;
public class Main {
private static EntityManagerFactory emf;
@Entity
public static class Employee {
@Id
@GeneratedValue(strategy = GenerationType.SEQUENCE)
private Long id;
}
public static void main(String[] args) throws SQLException {
emf = Persistence.createEntityManagerFactory("default");
EntityManager em = emf.createEntityManager();
em.getTransaction().begin();
Employee e = new Employee();
em.persist(e);
em.find(Employee.class, 1l, LockModeType.PESSIMISTIC_WRITE);
// Same behavior with:
// em.lock(e, LockModeType.PESSIMISTIC_WRITE);
em.close();
emf.close();
}
}
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[1]
{noformat}
Exception in thread "main" javax.persistence.OptimisticLockException: Row was updated or deleted by another transaction (or unsaved-value mapping was incorrect) : [cz.nguyen.entity.Employee#1]
at org.hibernate.internal.ExceptionConverterImpl.wrapStaleStateException(ExceptionConverterImpl.java:202)
at org.hibernate.internal.ExceptionConverterImpl.convert(ExceptionConverterImpl.java:88)
at org.hibernate.internal.ExceptionConverterImpl.convert(ExceptionConverterImpl.java:176)
at org.hibernate.internal.SessionImpl.find(SessionImpl.java:3431)
at org.hibernate.internal.SessionImpl.find(SessionImpl.java:3381)
at cz.nguyen.Main.main(Main.java:27)
Caused by: org.hibernate.StaleObjectStateException: Row was updated or deleted by another transaction (or unsaved-value mapping was incorrect) : [cz.nguyen.entity.Employee#1]
at org.hibernate.dialect.lock.PessimisticWriteSelectLockingStrategy.lock(PessimisticWriteSelectLockingStrategy.java:76)
at org.hibernate.persister.entity.AbstractEntityPersister.lock(AbstractEntityPersister.java:1802)
at org.hibernate.event.internal.AbstractLockUpgradeEventListener.upgradeLock(AbstractLockUpgradeEventListener.java:82)
at org.hibernate.event.internal.DefaultLoadEventListener.loadFromSessionCache(DefaultLoadEventListener.java:566)
at org.hibernate.event.internal.DefaultLoadEventListener.doLoad(DefaultLoadEventListener.java:441)
at org.hibernate.event.internal.DefaultLoadEventListener.load(DefaultLoadEventListener.java:219)
at org.hibernate.event.internal.DefaultLoadEventListener.lockAndLoad(DefaultLoadEventListener.java:403)
at org.hibernate.event.internal.DefaultLoadEventListener.doOnLoad(DefaultLoadEventListener.java:124)
at org.hibernate.event.internal.DefaultLoadEventListener.onLoad(DefaultLoadEventListener.java:89)
at org.hibernate.internal.SessionImpl.fireLoad(SessionImpl.java:1239)
at org.hibernate.internal.SessionImpl.access$1900(SessionImpl.java:203)
at org.hibernate.internal.SessionImpl$IdentifierLoadAccessImpl.doLoad(SessionImpl.java:2797)
at org.hibernate.internal.SessionImpl$IdentifierLoadAccessImpl.load(SessionImpl.java:2778)
at org.hibernate.internal.SessionImpl.find(SessionImpl.java:3407)
... 2 more
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