Hi Jan,
In any event I would advise against using "unregisterObjects", unless
you are sure there are no remaining cached objects that point to
unregistered objects via a relationship.
So if you are using "unregisterObjects" to save memory, I suggest
simply throwing away the DataContext and replacing it with a new one
(or use Cayenne 3.0M1 that would clean up unused registered objects
for you).
Andrus
P.S. So could you tell whether the problem described in the previous
thread is also caused by unregistering?
On Aug 14, 2007, at 11:35 AM, Jan Lendholt wrote:
Hey Folks,
me again with yet another problem which in my opinion seems to me
as a bag in cayenne.
Ok, the situation:
Create a dataset A, save (commit) and close the application. Then
open the application and create a dataset B - do NOT save (commit)
Changes and delete dataset A and dataset B.
Dataset A ist deleted by using context.deleteObject(objA) and
dataset B ist deleted by unregisterObjects(temp) where temp is a
collection withe objB in it.
Now on the commit of the changes we get an exception:
17:22:09.208 WARN!! Exception for /ams?serviceId=Echo.Synchronize
java.lang.NullPointerException: Attempt to add null target DataObject.
at org.apache.cayenne.CayenneDataObject.addToManyTarget
(CayenneDataObject.java:263)
at org.apache.cayenne.access.ChildDiffLoader.arcCreated
(ChildDiffLoader.java:111)
at org.apache.cayenne.access.ObjectDiff$ArcOperation.apply
(ObjectDiff.java:428)
at org.apache.cayenne.graph.CompoundDiff.apply(CompoundDiff.java:97)
at org.apache.cayenne.access.ObjectStoreGraphDiff.apply
(ObjectStoreGraphDiff.java:136)
at org.apache.cayenne.access.DataContext.onContextFlush
(DataContext.java:1180)
at org.apache.cayenne.access.DataContext.onSync(DataContext.java:
1159)
at org.apache.cayenne.access.DataContext.flushToParent
(DataContext.java:1226)
at org.apache.cayenne.access.DataContext.commitChanges
(DataContext.java:1130)
at ams.lieferanten.LieferantenCreateWindowPane.actionSave
(LieferantenCreateWindowPane.java:280)
at ams.lieferanten.LieferantenCreateWindowPane.access$4
(LieferantenCreateWindowPane.java:236)
at ams.lieferanten.LieferantenCreateWindowPane$7.actionPerformed
(LieferantenCreateWindowPane.java:489)
at nextapp.echo2.app.button.AbstractButton.fireActionPerformed
(AbstractButton.java:135)
at echopointng.ButtonEx$1.actionPerformed(ButtonEx.java:120)
at nextapp.echo2.app.button.DefaultButtonModel.fireActionPerformed
(DefaultButtonModel.java:70)
at echopointng.model.DefaultButtonModelEx.doAction
(DefaultButtonModelEx.java:51)
at echopointng.ButtonEx.processInput(ButtonEx.java:203)
at nextapp.echo2.app.update.ClientUpdateManager.process
(ClientUpdateManager.java:116)
at nextapp.echo2.app.update.UpdateManager.processClientUpdates
(UpdateManager.java:89)
at
nextapp.echo2.webcontainer.ContainerSynchronizeService.renderUpdate
(ContainerSynchronizeService.java:472)
at nextapp.echo2.webrender.service.SynchronizeService.service
(SynchronizeService.java:279)
at nextapp.echo2.webrender.WebRenderServlet.process
(WebRenderServlet.java:273)
at nextapp.echo2.webrender.WebRenderServlet.doPost
(WebRenderServlet.java:189)
at javax.servlet.http.HttpServlet.service(HttpServlet.java:760)
at javax.servlet.http.HttpServlet.service(HttpServlet.java:853)
at org.mortbay.jetty.servlet.ServletHolder.handle
(ServletHolder.java:356)
at org.mortbay.jetty.servlet.WebApplicationHandler$Chain.doFilter
(WebApplicationHandler.java:342)
at org.apache.cayenne.conf.WebApplicationContextFilter.doFilter
(WebApplicationContextFilter.java:91)
at org.mortbay.jetty.servlet.WebApplicationHandler$Chain.doFilter
(WebApplicationHandler.java:334)
at org.mortbay.jetty.servlet.WebApplicationHandler.dispatch
(WebApplicationHandler.java:286)
at org.mortbay.jetty.servlet.ServletHandler.handle
(ServletHandler.java:567)
at org.mortbay.http.HttpContext.handle(HttpContext.java:1776)
at org.mortbay.jetty.servlet.WebApplicationContext.handle
(WebApplicationContext.java:514)
at org.mortbay.http.HttpContext.handle(HttpContext.java:1726)
at org.mortbay.http.HttpServer.service(HttpServer.java:879)
at org.mortbay.http.HttpConnection.service(HttpConnection.java:790)
at org.mortbay.http.HttpConnection.handleNext(HttpConnection.java:
952)
at org.mortbay.http.HttpConnection.handle(HttpConnection.java:807)
at org.mortbay.http.SocketListener.handleConnection
(SocketListener.java:196)
at org.mortbay.util.ThreadedServer.handle(ThreadedServer.java:289)
at org.mortbay.util.ThreadPool$PoolThread.run(ThreadPool.java:487)
I tried to track it back and found out, that on unregisterObjects
the objects are being thrown out of the objectStore. Therefore we
get a Null value when searching for the object on commit.
Now we tried the "deleteObject" method to delete the objB which has
the state NEW. Neither dataset (objA, objB) is deleted. I am
wondering why.
We are just holding some objects temporarily in the samte context
with alread saved data in the database.
Is it a bug?
Thanks in advance!
Jan
