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Posted to user@cayenne.apache.org by Peter <pe...@yahoo.de> on 2006/11/28 23:48:01 UTC
NullPointerException when setting deletion rules
Hallo!
I reduced my application code to the following:
-------------------------------------------------
ArrayList temporaryObjects = new ArrayList();
DataContext context = DataContext.createDataContext();
Room r = (Room) context.createAndRegisterNewObject(Room.class);
r.setName("testRoom");
temporaryObjects.add(r);
TimeInterval ti =
(TimeInterval)context.createAndRegisterNewObject(TimeInterval.class);
temporaryObjects.add(ti);
ti.setToOneTarget("room", r, false);
context.deleteObjects(temporaryObjects);
temporaryObjects.clear();
context.commitChanges();
-------------------------------------------------
where I get a NPE at 'context.deleteObjects':
-------------------------------------------------
Exception in thread "main" java.lang.NullPointerException
at
org.objectstyle.cayenne.CayenneDataObject.removeToManyTarget(CayenneDataObject.java:281)
at
org.objectstyle.cayenne.access.DataContextDeleteAction.processDeleteRules(DataContextDeleteAction.java:239)
at
org.objectstyle.cayenne.access.DataContextDeleteAction.deleteNew(DataContextDeleteAction.java:149)
at
org.objectstyle.cayenne.access.DataContextDeleteAction.performDelete(DataContextDeleteAction.java:131)
at
org.objectstyle.cayenne.access.DataContext.deleteObject(DataContext.java:1043)
at
org.objectstyle.cayenne.access.DataContext.deleteObjects(DataContext.java:1027)
-------------------------------------------------
I don't get this if I do
ti.setToOneTarget("room", r, -->true<--);
But I need both: uni AND bidirectional relationships!
Here the mapping:
-------------------------------------------------
<?xml version="1.0" encoding="utf-8"?>
<data-map project-version="1.1">
<property name="defaultPackage" value="caybug"/>
<db-entity name="ROOM">
<db-attribute name="NAME" type="VARCHAR" length="24"/>
<db-attribute name="R_ID" type="INTEGER" isPrimaryKey="true"
isMandatory="true"/>
</db-entity>
<db-entity name="TIME_INTERVAL">
<db-attribute name="ROOM_FK" type="INTEGER"/>
<db-attribute name="TI_ID" type="INTEGER" isPrimaryKey="true"
isMandatory="true"/>
</db-entity>
<obj-entity name="Room" className="caybug.Room" dbEntityName="ROOM">
<obj-attribute name="name" type="java.lang.String"
db-attribute-path="NAME"/>
</obj-entity>
<obj-entity name="TimeInterval" className="caybug.TimeInterval"
dbEntityName="TIME_INTERVAL">
</obj-entity>
<db-relationship name="TIME_INTERVALS" source="ROOM"
target="TIME_INTERVAL" toMany="true">
<db-attribute-pair source="R_ID" target="ROOM_FK"/>
</db-relationship>
<db-relationship name="ROOM" source="TIME_INTERVAL" target="ROOM"
toMany="false">
<db-attribute-pair source="ROOM_FK" target="R_ID"/>
</db-relationship>
<obj-relationship name="timeIntervals" source="Room"
target="TimeInterval" deleteRule="Nullify"
db-relationship-path="TIME_INTERVALS"/>
<obj-relationship name="room" source="TimeInterval" target="Room"
deleteRule="Nullify" db-relationship-path="ROOM"/>
</data-map>
-------------------------------------------------
What is wrong? I used the default generated Room and TimeInterval classes.
Thank you, Peter.
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Re: NullPointerException when setting deletion rules
Posted by Peter Karich <pe...@yahoo.de>.
Hallo again!
Now the 'real' applications works, too!
A second possible solution (only for the case of my app) is to delete
the timeintervals before the rooms!
Thank you, Peter.
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Re: NullPointerException when setting deletion rules
Posted by Peter Karich <pe...@yahoo.de>.
Hallo!
Thank you Andrus, I will try it out. In my prepared example this fix helps!
> In the meantime you may have to manually break relationship cycles
> before deleting objects. E.g.:
> ti.setToOneTarget("room", null, false);
Puuh, I have a lot of TimeIntervals in my real app :-)
> Hmm... I'd say Cayenne should be smarter about this case.
> Could you please open a bug report?
I have never done before so take a look, please.
Peter.
PS: Michael Gentry, thank you for the link!!
(http://www.stepwise.com/Articles/2005/DBChanges/index.html)
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Re: NullPointerException when setting deletion rules
Posted by Andrus Adamchik <an...@objectstyle.org>.
Hmm... I'd say Cayenne should be smarter about this case. Could you
please open a bug report?
In the meantime you may have to manually break relationship cycles
before deleting objects. E.g.:
ti.setToOneTarget("room", null, false);
Andrus
On Nov 29, 2006, at 1:48 AM, Peter wrote:
> Hallo!
>
> I reduced my application code to the following:
>
> -------------------------------------------------
> ArrayList temporaryObjects = new ArrayList();
> DataContext context = DataContext.createDataContext();
>
> Room r = (Room) context.createAndRegisterNewObject
> (Room.class);
> r.setName("testRoom");
> temporaryObjects.add(r);
>
> TimeInterval ti = (TimeInterval)
> context.createAndRegisterNewObject(TimeInterval.class);
> temporaryObjects.add(ti);
> ti.setToOneTarget("room", r, false);
>
> context.deleteObjects(temporaryObjects);
> temporaryObjects.clear();
>
> context.commitChanges();
> -------------------------------------------------
>
> where I get a NPE at 'context.deleteObjects':
>
> -------------------------------------------------
> Exception in thread "main" java.lang.NullPointerException
> at
> org.objectstyle.cayenne.CayenneDataObject.removeToManyTarget
> (CayenneDataObject.java:281)
> at
> org.objectstyle.cayenne.access.DataContextDeleteAction.processDeleteRu
> les(DataContextDeleteAction.java:239)
> at
> org.objectstyle.cayenne.access.DataContextDeleteAction.deleteNew
> (DataContextDeleteAction.java:149)
> at
> org.objectstyle.cayenne.access.DataContextDeleteAction.performDelete
> (DataContextDeleteAction.java:131)
> at org.objectstyle.cayenne.access.DataContext.deleteObject
> (DataContext.java:1043)
> at org.objectstyle.cayenne.access.DataContext.deleteObjects
> (DataContext.java:1027)
> -------------------------------------------------
>
> I don't get this if I do
> ti.setToOneTarget("room", r, -->true<--);
>
> But I need both: uni AND bidirectional relationships!
> Here the mapping:
>
> -------------------------------------------------
> <?xml version="1.0" encoding="utf-8"?>
> <data-map project-version="1.1">
> <property name="defaultPackage" value="caybug"/>
> <db-entity name="ROOM">
> <db-attribute name="NAME" type="VARCHAR" length="24"/>
> <db-attribute name="R_ID" type="INTEGER" isPrimaryKey="true"
> isMandatory="true"/>
> </db-entity>
> <db-entity name="TIME_INTERVAL">
> <db-attribute name="ROOM_FK" type="INTEGER"/>
> <db-attribute name="TI_ID" type="INTEGER" isPrimaryKey="true"
> isMandatory="true"/>
> </db-entity>
> <obj-entity name="Room" className="caybug.Room" dbEntityName="ROOM">
> <obj-attribute name="name" type="java.lang.String" db-attribute-
> path="NAME"/>
> </obj-entity>
> <obj-entity name="TimeInterval" className="caybug.TimeInterval"
> dbEntityName="TIME_INTERVAL">
> </obj-entity>
> <db-relationship name="TIME_INTERVALS" source="ROOM"
> target="TIME_INTERVAL" toMany="true">
> <db-attribute-pair source="R_ID" target="ROOM_FK"/>
> </db-relationship>
> <db-relationship name="ROOM" source="TIME_INTERVAL" target="ROOM"
> toMany="false">
> <db-attribute-pair source="ROOM_FK" target="R_ID"/>
> </db-relationship>
> <obj-relationship name="timeIntervals" source="Room"
> target="TimeInterval" deleteRule="Nullify" db-relationship-
> path="TIME_INTERVALS"/>
> <obj-relationship name="room" source="TimeInterval" target="Room"
> deleteRule="Nullify" db-relationship-path="ROOM"/>
> </data-map>
> -------------------------------------------------
>
> What is wrong? I used the default generated Room and TimeInterval
> classes.
>
> Thank you, Peter.