Hi Armin,
I did see the more detailed error from OJB. The error happened on
a different set of classes this time.
[try to set 'object value' in 'target object'
target obj class: com.cisco.ipce.engine.datamodel.CUEUserGroup
target field name: lnkCUEPrivilege*
target field type: class com.cisco.ipce.engine.datamodel.CUEPrivilege
*target field declared in: com.cisco.ipce.engine.datamodel.CUEUserGroup
*object value class: com.cisco.ipce.engine.datamodel.CUEUserGroup
*object value: [EMAIL PROTECTED]
]
After a lot of debugging the root cause seems to be a corrupted
cache caused by a duplicate OID for a class in the same hierarchy.
In the above example, CUEUserGroup holds a reference to CUEPrivilege and
both are instances of the same base class.
During insertion of the CUEUserGroup, the SequenceManager allocates a
primary key id to CUEUserGroup but needs a trip to the OJB_HL_SEQ to get
an ID for the CUEPrivilege.
Due to the way our application is designed, we end up removing the OJB_HL_SEQ
from the database before this operation. OJB hence calculates the new
highest primary key value by searching across all extent classes in
the database.
SequenceManagerHelper.getMaxForExtent
does not take into account the ID allocated to the CUEUserGroup since
it only searches in the database for the maximum primary key allocated
so far. It hence ends up allocating the same ID to the CUEPrivilege
inserted next.
This finally causes the cache to pick up a CUEUserGroup class instead
of the CUEPrivilege while setting the linkCUEPrivilege data member on
CUEUserGroup and leads to the exception from Java.
I would think that either the OJB documentation should warn against
deletion of the OJB_HL_SEQ entry OR ensure that this corner case is handled.
Pls let me know what you feel.
Rgds,
Rajesh
Hi Rajesh,
Rajesh T V wrote:
Hi Armin,
Thanks for your reply.Reply inline.
-Rajesh
does OJB log a more detailed error message?
no
Please search for this message in your log file again. If you use OJB
1.0.3 or higher OJB will log a detailed error message before the
exception was thrown.
For 1.0.3 it begins with "try to set 'object value' in 'target
object..." or something similar.
Please post the whole stack trace with the logging messages before the
exception occur.
regards,
Armin
On 4/27/06, Rajesh T V <[EMAIL PROTECTED]> wrote:
Hi,
We are hitting an intermittent issue with db-ojb-1.0.3.
At random times we hit the following exception while ojb
tries to create an object from a Derby db.
org.apache.ojb.broker.PersistenceBrokerException:
org.apache.ojb.broker.metadata.MetadataException: IllegalAccess error
setting field:userAccount in
object:com.cisco.ipce.engine.datamodel.EndUser
at org.apache.ojb.broker.core.QueryReferenceBroker.getCollectionByQuery
(Unknown
Source)
at org.apache.ojb.broker.core.QueryReferenceBroker.getCollectionByQuery
(Unknown
Source)
at org.apache.ojb.broker.core.PersistenceBrokerImpl.getCollectionByQuery
(Unknown
Source)
at
org.apache.ojb.broker.core.DelegatingPersistenceBroker.getCollectionByQuery
(Unknown
Source)
at
org.apache.ojb.broker.core.DelegatingPersistenceBroker.getCollectionByQuery
(Unknown
Source)
at com.cisco.ipce.engine.sal.dataaccess.DBDAO.get(DBDAO.java:367)
The root cause being a
Caused by: java.lang.IllegalArgumentException at
sun.reflect.UnsafeObjectFieldAccessorImpl.set(
UnsafeObjectFieldAccessorImpl.java:63)
at java.lang.reflect.Field.set(Field.java:656)
... 59 more
The error occurs on different classes at different times. Once we hit
the error, it does
not go away no matter what we do (tomcat restart etc). Once the
problem stops happening
(sometimes on pc restart) it never happens again for a long time.
Our repository_user.xml for all classes are similar.
<class-descriptor class="com.cisco.ipce.engine.datamodel.EndUser"
table="UserBase">
<field-descriptor column="OID" jdbc-type="INTEGER" name="OID"
autoincrement="true" primarykey="true"/>
<field-descriptor column="userAccountId" jdbc-type="INTEGER"
name="userAccountId"/>
<reference-descriptor name="userAccount"
class-ref="com.cisco.ipce.engine.datamodel.IPCEUserAccount"
auto-retrieve="true" auto-update="object" auto-delete="object" >
<foreignkey field-ref="userAccountId"/>
</reference-descriptor>
<field-descriptor column="type" jdbc-type="INTEGER" name="type"/>
public class EndUser extends UserBase {
...
...
}
public abstract class UserBase extends IPCEObject{
...
....
protected UserAccount userAccount;
...
}
I am not sure what we are doing wrong and even if we are why is the
error intermittent ?
All classes where the error occurs have the same pattern where a
protected attribute
of the super-class is being set via the sub-class repository_user.xml
entry. The attribute
is always an auto-retrieve=true; auto-update="object" and
auto-delete="object" class to
which the offending class holds a foreign key.
Any help appreciated.
Thanks,
Rajesh
