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From "Eric Floehr" <Eric.Flo...@3x.com>
Subject RE: NullPointerException in Derby driver (from at least 10.2.2.0)
Date Wed, 13 Feb 2008 22:23:01 GMT
Jim,

Yes, I would say that is a reasonable work-around.  In our case, we
built the networking code, so we saw where the interrupt was being
handled but the flag not reset, so we were able to fix it at the source.
But barring that, resetting it prior to a derby write/commit should
work.

Regards,
Eric


> -----Original Message-----
> From: Jim Newsham [mailto:jnewsham@referentia.com]
> Sent: Wednesday, February 13, 2008 4:54 PM
> To: 'Derby Discussion'
> Subject: RE: NullPointerException in Derby driver (from at least
> 10.2.2.0)
> 
> 
> Thanks for the advice Eric.  It seems from DERBY-151 that calling
> Thread.interrupted() before calling commit() is a reasonable
workaround
> until the problem is fixed.  Is this your assessment?
> 
> Might also be desirable to save the result and re-interrupt afterwards
> if
> interrupt status must be preserved (which it generally should).
Though
> perhaps the same problem might be manifested in other parts of the
> driver.
> 
> Thanks,
> Jim
> 
> > -----Original Message-----
> > From: Eric Floehr [mailto:Eric.Floehr@3x.com]
> > Sent: Wednesday, February 13, 2008 11:39 AM
> > To: Derby Discussion
> > Subject: RE: NullPointerException in Derby driver (from at least
> 10.2.2.0)
> >
> > Jim,
> >
> > That's definitely what we are seeing, and our only option was to
> restart
> > the app as well.  You should really check the interrupt, because it
> > wasn't so much that InterruptedException was thrown at your code in
> the
> > thread for us.  What was happening is the interrupt flag was getting
> set
> > down in the network layer, the interrupt was successfully handled
> there,
> > but the interrupt flag was not getting cleared.  So then, next time
> > there was a commit on the database (in a totally separate part of
the
> > code) on that thread, we had the problem.
> >
> > -Eric
> >
> > > -----Original Message-----
> > > From: Jim Newsham [mailto:jnewsham@referentia.com]
> > > Sent: Wednesday, February 13, 2008 2:30 PM
> > > To: 'Derby Discussion'
> > > Subject: RE: NullPointerException in Derby driver (from at least
> > > 10.2.2.0)
> > >
> > >
> > > I have been seeing this same problem (very) intermittently as
> well...
> > > just
> > > have been way too busy with other things at the time to look into
> it.
> > > When
> > > it occurs, I generally see a NullPointerException on commit, and
> > > subsequent
> > > usage of the (statement? connection? data source? not sure
exactly)
> > > gives
> > > "No current connection" errors.  Our application needs to be
> restarted
> > > to
> > > recover, so I think the data source is no longer usable.
> > >
> > > This is with embedded 10.3.2.1.  Not sure if the thread is being
> > > interrupted
> > > in this case.  I think not, but could be wrong.
> > >
> > > Jim
> > >
> > > > -----Original Message-----
> > > > From: Daniel Noll [mailto:daniel@nuix.com]
> > > > Sent: Tuesday, February 05, 2008 6:17 PM
> > > > To: Derby Discussion
> > > > Subject: Re: NullPointerException in Derby driver (from at least
> > > 10.2.2.0)
> > > >
> > > > On Wednesday 06 February 2008 04:00:26 Eric Floehr wrote:
> > > > > All,
> > > > > I'm experiencing a NullPointerException (somewhat random)
> > > apparently
> > > > > within the Derby JDBC driver (stack trace below), and am
> wondering
> > > if
> > > > > anyone has any suggestions on finding the root cause.  I am
> using
> > > Derby
> > > > > 10.3.2.1 (though the problem also occurred on 10.2.2.0) with
an
> > > IBATIS
> > > > > front-end (version 2.3.1.700, though it also occurred with
> 2.2),
> > > using
> > > > > Derby in single-user mode (direct not via server).
> > > >
> > > > Interesting, I found exactly the same problem.  I'm not sure
> whether
> > > I
> > > > posted
> > > > about it to the list or whether I stayed quiet.
> > > >
> > > > Do you have another warning earlier in the log about the
> connection
> > > having
> > > > been closed?  The few times I've seen this, the connection has
> > > "closed
> > > > itself" (despite being embedded, and thus having no good reason
> > > to...) and
> > > > then I've seen these errors for all operations directly
> afterwards.
> > > >
> > > > Daniel
> > >
> > >
> >
> 
> 


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