DetachedStageManager misere

[Mark Struberg <st...@yahoo.de>]

Hi folks!

I just get grey hairs with the DetachedStateManager

my situation:

.) with default detach strategy
  -> error in @PostLoad see OPENJPA-1873
  -> error in storing Null Values at em.merge()

.) with detach strategy fetch-groups
  -> ElementCollections don't get stored

.) with fgs(DetachedStateField=true)
  -> funny crash with improper cast when the entity gets serialized:
java.lang.ClassCastException: org.apache.openjpa.kernel.StateManagerImpl cannot be cast to org.apache.openjpa.kernel.DetachedStateManager
	at org.apache.openjpa.util.Proxies.writeReplace(Proxies.java:147)
	at org.apache.openjpa.util.java$util$Date$proxy.writeReplace(Unknown Source)
	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 java.io.ObjectStreamClass.invokeWriteReplace(ObjectStreamClass.java:1032)
	at java.io.ObjectOutputStream.writeObject0(ObjectOutputStream.java:1107)
	at java.io.ObjectOutputStream.writeObject(ObjectOutputStream.java:326)
	at org.apache.openjpa.kernel.SingleFieldManager.serialize(SingleFieldManager.java:540)
	at org.apache.openjpa.kernel.StateManagerImpl.writeDetached(StateManagerImpl.java:1478)
	at at.ac.tuwien.tiss.education.be.entities.ExamDate.writeExternal(ExamDate.java)
	at java.io.ObjectOutputStream.writeExternalData(ObjectOutputStream.java:1421)
	at java.io.ObjectOutputStream.writeOrdinaryObject(ObjectOutputStream.java:1390)
	at java.io.ObjectOutputStream.writeObject0(ObjectOutputStream.java:1150)
	at java.io.ObjectOutputStream.writeObject(ObjectOutputStream.java:326)
	at java.util.ArrayList.writeObject(ArrayList.java:570)


So what to do? I'm willing to spend a reasonable amount of time to create unit tests for those scenarios to help improve OpenJPA. I also already have a medium profound knowledge of OpenJPA internals to help fixing those issues. But I most probably need a few hints to get the right initial direction. 

So my first question would be: which detach strategy is the way to go for a standard JSF application which uses the entitymanager-per-request pattern? The default one (loaded)? 

txs and LieGrue,
strub