Jpa delete PreRemove issue

[Ludocwi]

Hi,
I have a ManyToOne relation issue ... (to be original)
I have 2 entities, Original and Copy, and a ManyToOne relation between
Copy and Original.
A Copy can live independently from a Original.
So when I want to delete a Original, I want to keep the Copy(s).
So There is my code :

@Entity
public class Original extends Model {
...

@PreRemove
public void preRemove() {
for (Copy copy : Copy.findAll()) {
copy.original = null;
copy.save();
}
}
}

@Entity
public class Copy extends Model {
...

@ManyToOne
public Original original;
}

It works but the Hibernate doc says it is forbidden to flush during
@PreRemove.
So how can I do this without calling .save() ? Have I to use
@PreRemove ?

Thx
Ludo

[Guillaume Bort]

Perhaps you can try PostRemove?

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[Ludocwi]

Actually, I can't use .save() in any callback methods as it is said
here : "A callback method must not invoke EntityManager or Query
methods!"
http://docs.jboss.org/hibernate/stable/entitymanager/reference/en/html/listeners.html
(table 6.1)

When I delete a Original entity, I could remove Original reference
from Copy in my controllers before, but I think it is not suitable.
And when I keep calling .save() in @PreRemove, and there is a Cascade
Delete which deletes Original I get a HibernateException : "Flush
during cascade is Dangerous"

> Guillaume Bort,http://guillaume.bort.fr

>
> For anything work-related, use g...@zenexity.fr; for everything else,

> write guillaume.b...@gmail.com

[Julien Tournay]

Can't you simply force hibernate to NOT cascade on delete, so that when you delete an an Original, copy is not deleted ?

jto.

Real Programmers don't need comments-- the code is obvious.

[Ludocwi]

I don't cascade on deleting Original Entity (because I want to keep
Copy) but I cascade on delete Library entity which contains
Original(s) :

@Entity
public class Library extends Model {
...

@OneToMany(mappedBy = "library", cascade = CascadeType.REMOVE )
public Set<Original> originals;

}

So when I delete a Library, I get the HibernateException "Flush
during cascade is Dangerous"...

I don't know if I am understandable ... :s

On 1 oct, 14:14, Julien Tournay <boudhe...@gmail.com> wrote:
> Can't you simply force hibernate to NOT cascade on delete, so that when you
> delete an an Original, copy is not deleted ?
>
> jto.
>
>
>
> On Fri, Oct 1, 2010 at 2:02 PM, Ludocwi <ludoch...@gmail.com> wrote:
> > Actually, I can't use .save() in any callback methods as it is said
> > here : "A callback method must not invoke EntityManager or Query
> > methods!"
>

> >http://docs.jboss.org/hibernate/stable/entitymanager/reference/en/htm...

> > play-framewor...@googlegroups.com<play-framework%2Bunsu...@googlegroups.com>
> > .

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>
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>
> > > For anything work-related, use g...@zenexity.fr; for everything else,
> > > write guillaume.b...@gmail.com
>
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[Julien Tournay]

Unless I'm missing something (which is likely),

if Hibernate deletes the Copies when an Original is deleted, it means that for some reason, the delete is cascaded.

It's confusing because I don't think Hibernate is supposed to do that by default.
Could you share a minimal Play! app with the problem?

jto

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[Ludocwi]

No no, Hibernate does not delete the Copies when an Original is
deleted. (I want to keep the Copies)
When I delete a Original I just want to do Copy.Original = null before
deleting Original, if not I get the Exception below because Copy is
still pointing to Original : (that's why I try to

for (Copy copy : Copy.findAll()) {
copy.original = null;
copy.save();
}

in a @PreRemove)
Ok I'll try to provide you a Play app

15:49:49,171 ERROR ~ failed batch
15:49:49,172 ERROR ~ Could not synchronize database state with session
org.hibernate.exception.GenericJDBCException: Could not execute JDBC
batch update
at
org.hibernate.exception.SQLStateConverter.handledNonSpecificException(SQLStateConverter.java:
140)
at
org.hibernate.exception.SQLStateConverter.convert(SQLStateConverter.java:
128)
at
org.hibernate.exception.JDBCExceptionHelper.convert(JDBCExceptionHelper.java:
66)
at
org.hibernate.jdbc.AbstractBatcher.executeBatch(AbstractBatcher.java:
275)
at org.hibernate.engine.ActionQueue.executeActions(ActionQueue.java:
262)
at org.hibernate.engine.ActionQueue.executeActions(ActionQueue.java:
183)
at
org.hibernate.event.def.AbstractFlushingEventListener.performExecutions(AbstractFlushingEventListener.java:
324)
at
org.hibernate.event.def.DefaultFlushEventListener.onFlush(DefaultFlushEventListener.java:
51)
at org.hibernate.impl.SessionImpl.flush(SessionImpl.java:1206)
at
org.hibernate.ejb.AbstractEntityManagerImpl.flush(AbstractEntityManagerImpl.java:
791)
at play.db.jpa.JPABase._delete(JPABase.java:73)
at play.db.jpa.GenericModel.delete(GenericModel.java:197)
at models.FormulaTest.deleteTest(FormulaTest.java:14)
at sun.reflect.NativeMethodAccessorImpl.invoke0(Native Method)
at
sun.reflect.NativeMethodAccessorImpl.invoke(NativeMethodAccessorImpl.java:
39)
at
sun.reflect.DelegatingMethodAccessorImpl.invoke(DelegatingMethodAccessorImpl.java:
25)
at java.lang.reflect.Method.invoke(Method.java:597)
at org.junit.runners.model.FrameworkMethod
$1.runReflectiveCall(FrameworkMethod.java:44)
at
org.junit.internal.runners.model.ReflectiveCallable.run(ReflectiveCallable.java:
15)
at
org.junit.runners.model.FrameworkMethod.invokeExplosively(FrameworkMethod.java:
41)
at
org.junit.internal.runners.statements.InvokeMethod.evaluate(InvokeMethod.java:
20)
at
org.junit.internal.runners.statements.RunBefores.evaluate(RunBefores.java:
28)
at
org.junit.runners.BlockJUnit4ClassRunner.runChild(BlockJUnit4ClassRunner.java:
76)
at
org.junit.runners.BlockJUnit4ClassRunner.runChild(BlockJUnit4ClassRunner.java:
50)
at org.junit.runners.ParentRunner$3.run(ParentRunner.java:193)
at org.junit.runners.ParentRunner$1.schedule(ParentRunner.java:52)
at org.junit.runners.ParentRunner.runChildren(ParentRunner.java:191)
at org.junit.runners.ParentRunner.access$000(ParentRunner.java:42)
at org.junit.runners.ParentRunner$2.evaluate(ParentRunner.java:184)
at org.junit.runners.ParentRunner.run(ParentRunner.java:236)
at org.junit.runners.Suite.runChild(Suite.java:128)
at org.junit.runners.Suite.runChild(Suite.java:24)
at org.junit.runners.ParentRunner$3.run(ParentRunner.java:193)
at org.junit.runners.ParentRunner$1.schedule(ParentRunner.java:52)
at org.junit.runners.ParentRunner.runChildren(ParentRunner.java:191)
at org.junit.runners.ParentRunner.access$000(ParentRunner.java:42)
at org.junit.runners.ParentRunner$2.evaluate(ParentRunner.java:184)
at org.junit.runners.ParentRunner.run(ParentRunner.java:236)
at org.junit.runner.JUnitCore.run(JUnitCore.java:157)
at org.junit.runner.JUnitCore.run(JUnitCore.java:136)
at org.junit.runner.JUnitCore.run(JUnitCore.java:117)
at play.test.TestEngine.run(TestEngine.java:124)
at controllers.TestRunner.run(TestRunner.java:66)
at sun.reflect.NativeMethodAccessorImpl.invoke0(Native Method)
at
sun.reflect.NativeMethodAccessorImpl.invoke(NativeMethodAccessorImpl.java:
39)
at
sun.reflect.DelegatingMethodAccessorImpl.invoke(DelegatingMethodAccessorImpl.java:
25)
at java.lang.reflect.Method.invoke(Method.java:597)
at play.mvc.ActionInvoker.invokeControllerMethod(ActionInvoker.java:
408)
at play.mvc.ActionInvoker.invokeControllerMethod(ActionInvoker.java:
403)
at play.mvc.ActionInvoker.invoke(ActionInvoker.java:176)
at play.server.PlayHandler$NettyInvocation.execute(PlayHandler.java:
162)
at play.Invoker$Invocation.run(Invoker.java:187)
at play.server.PlayHandler$NettyInvocation.run(PlayHandler.java:142)
at java.util.concurrent.Executors$RunnableAdapter.call(Executors.java:
441)
at java.util.concurrent.FutureTask$Sync.innerRun(FutureTask.java:303)
at java.util.concurrent.FutureTask.run(FutureTask.java:138)
at java.util.concurrent.ScheduledThreadPoolExecutor
$ScheduledFutureTask.access$301(ScheduledThreadPoolExecutor.java:98)
at java.util.concurrent.ScheduledThreadPoolExecutor
$ScheduledFutureTask.run(ScheduledThreadPoolExecutor.java:207)
at java.util.concurrent.ThreadPoolExecutor
$Worker.runTask(ThreadPoolExecutor.java:886)
at java.util.concurrent.ThreadPoolExecutor
$Worker.run(ThreadPoolExecutor.java:908)
at java.lang.Thread.run(Thread.java:619)
Caused by: java.sql.BatchUpdateException: failed batch
at org.hsqldb.jdbc.jdbcStatement.executeBatch(Unknown Source)
at org.hsqldb.jdbc.jdbcPreparedStatement.executeBatch(Unknown Source)
at
com.mchange.v2.c3p0.impl.NewProxyPreparedStatement.executeBatch(NewProxyPreparedStatement.java:
1723)
at
org.hibernate.jdbc.BatchingBatcher.doExecuteBatch(BatchingBatcher.java:
70)
at
org.hibernate.jdbc.AbstractBatcher.executeBatch(AbstractBatcher.java:
268)
... 57 more

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>
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[Julien Tournay]

Oh ok, sorry, I just misunderstood the whole problem ;)

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[Ludocwi]

I uploaded a play app here : git://github.com/ludochane/Play-jpatest-issue.git
In this app, I created entities which uses @PreRemove or not, and 2
tests.

Thank you

On 1 oct, 16:15, Julien Tournay <boudhe...@gmail.com> wrote:
> Oh ok, sorry, I just misunderstood the whole problem ;)
>

> ...
>
> plus de détails »

[Guillaume Bort]

You should override delete() directly.

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--
Guillaume Bort, http://guillaume.bort.fr

For anything work-related, use g...@zenexity.fr; for everything else,

write guillau...@gmail.com

[Ludocwi]

If I override delete(), It does not cascade well. I will look into
that more deeply.
Thx for the help

On 1 oct, 17:51, Guillaume Bort <guillaume.b...@gmail.com> wrote:
> You should override delete() directly.
>

> ...
>
> plus de détails »

[Preslav Rachev]

Amazing! Almost four years later, I ended up having exactly the same problem. Now, I am struggling to find a solution. Have you figured something out in the meantime?

Thanks,

Preslav

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>
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> > > write guillaume.b...@gmail.com
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