Re: NullPointerException only after first call to batchFetchRelationship

Sorry, I'd gotten mixed up on which list this was from.

On Monday, Dec 15, 2003, at 20:49 America/New_York, Lenny Marks wrote:

> I had tracked it down in my case, see if this helps you any.
>
> http://www.omnigroup.com/mailman/archive/eof/2003-August/003393.html

Of course the EOObjectStoreCoordinator should be manually locked and  
unlocked in the code from that posting. (As originally pointed out by  
Chuck if I remember correctly)

-lenny

EOObjectStoreCoordinator osc =  
(EOObjectStoreCoordinator)ec.rootObjectStore();

osc.lock();
try {
     EODatabaseContext dbContext = (EODatabaseContext)
             osc.objectStoreForObject(this);

     EOEntity correspondenceEntity =
             EOUtilities.entityNamed(ec, "CorrespondenceEvent");

     EORelationship corrRelationship =
             correspondenceEntity.relationshipNamed("correspondence");

      dbContext.batchFetchRelationship
             (corrRelationship, correspondenceEvents, ec);
} finally {
    osc.unlock();
}

>
> On Sunday, Dec 14, 2003, at 12:08 America/New_York, Kaj Hejer wrote:
>
>> At 08:57 -0400 17-08-03, Lenny Marks wrote:
>>> I have a direct action to render all information for a specified
>>> 'Manuscript' in our database. The rendering of this page traces deep  
>>> into
>>> the manuscript's relationships and was slow so I was attempting to  
>>> use
>>> EODatabaseContext.batchFetchRelationship to limit the hits to the
>>> database. I added a method batchFetchManuscriptEvents(the root of  
>>> the deep
>>> relationships) to my Manuscript EOEnterpriseObject class. I was  
>>> hoping
>>> that the application could call this in anticipation of its  
>>> particular
>>> display needs. The method would batchFetch all the relationships so  
>>> that
>>> by the time the WOComponent was generating its response, all the
>>> relationships would have already been faulted. This actually worked,  
>>> but
>>> only the first time the method is invoked on a Manuscript instance  
>>> within
>>> a single EOF stack. The first time I access the direct action for a
>>> manuscript, it works, but if I hit reload I get the exception below.
>>>
>>> Any clues would be greatly appreciated!
>>>
>>> -Lenny Marks
>>>
>>> <ManView>[2003-08-17 07:49:16 EDT] <Thread-6>
>>> java.lang.NullPointerException
>>>         at
>>> com.webobjects.eocontrol._EOMutableKnownKeyDictionary.<init>(_EOMutab 
>>> leKnownKeyDictionary.java:90)
>>>         at
>>> com.webobjects.eoaccess.EORelationship._foreignKeyForSourceRow(EORela 
>>> tionship.java:1094)
>>
>>
>>
>>
>> Hi!
>>
>> I now saw the same exception when using prefetching.
>>
>> The stacktrace and the method where I get this exception can be found  
>> at http://folk.uio.no/kajh/tmp/wo20031214.txt
>>
>> Has anybody else here seen this?
>>
>> The ec I use here is a childEC of session.defaulteditingContext and  
>> this childEC has been locked.
>>
>> I have only managed to reproduced this issue two times while testing  
>> this application for about an hour, so it seems that it does not  
>> appear so very often.
>>
>>
>> -Kaj :)
>
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