Hello, Rick: Thank you for your prompt response. I'm currently using Derby 10.8.2.2. Should I use the same version or upgrade?
Can you please also advise which debug jars I can use? Thx, Pavel. -----Original Message----- From: Rick Hillegas [mailto:rick.hille...@oracle.com] Sent: Monday, December 10, 2012 1:05 PM To: derby-user@db.apache.org Subject: Re: NPE Hi Pavel, Can you reproduce this problem with the debug version of Derby? That would give us line numbers in the stack trace. Thanks, -Rick On 12/10/12 9:23 AM, Pavel Bortnovskiy wrote: > > Hello: > > While testing my application, which uses Derby in memory-only mode, I > get NPE inside Derby under "mysterious" circumstances. > > At this point, I can't even figure out what's triggering it and where > this could happen, but let me preempt my troubleshooting with some > stack traces. Perhaps someone, with good knowledge of Derby's code, > may offer some explanation. Here are some stack traces: > > Mon Dec 10 12:12:36 EST 2012 Thread[DatabasePublisher[WRITER],5,main] > (XID = 235), (SESSIONID = 5), (DATABASE = memory:test), (DRDAID = > null), Failed Statement is: select * from READER > > java.lang.NullPointerException > > at > org.apache.derby.impl.store.access.conglomerate.GenericScanController. > reopenAfterEndTransaction(Unknown > Source) > > at > org.apache.derby.impl.store.access.conglomerate.GenericScanController. > fetchRows(Unknown > Source) > > at > org.apache.derby.impl.store.access.heap.HeapScan.fetchNextGroup(Unknow > n Source) > > at > org.apache.derby.impl.sql.execute.BulkTableScanResultSet.reloadArray(U > nknown > Source) > > at > org.apache.derby.impl.sql.execute.BulkTableScanResultSet.getNextRowCor > e(Unknown > Source) > > at > org.apache.derby.impl.sql.execute.ProjectRestrictResultSet.getNextRowC > ore(Unknown > Source) > > at > org.apache.derby.impl.sql.execute.ScrollInsensitiveResultSet.getNextRo > wFromSource(Unknown > Source) > > at > org.apache.derby.impl.sql.execute.ScrollInsensitiveResultSet.getNextRo > wCore(Unknown > Source) > > at > org.apache.derby.impl.sql.execute.BasicNoPutResultSetImpl.getNextRow(U > nknown > Source) > > at org.apache.derby.impl.jdbc.EmbedResultSet.movePosition(Unknown > Source) > > at org.apache.derby.impl.jdbc.EmbedResultSet.next(Unknown Source) > > at QueryResults$1.hasNext(QueryResults.java:268) > > at DatabasePublisher.process(DatabasePublisher.java:318) > > at java.lang.Thread.run(Thread.java:662) > > or > > 2012-12-10 12:12:36,537 [DatabasePublisher[WRITER]] ERROR QueryResults > - Unable to execute ResultSet.next() for Statement ""select * from > READER" [DERBY]" > > java.sql.SQLException: Java exception: ': java.lang.NullPointerException'. > > at > org.apache.derby.impl.jdbc.SQLExceptionFactory40.getSQLException(Unkno > wn > Source) > > at org.apache.derby.impl.jdbc.Util.newEmbedSQLException(Unknown > Source) > > at org.apache.derby.impl.jdbc.Util.javaException(Unknown Source) > > at > org.apache.derby.impl.jdbc.TransactionResourceImpl.wrapInSQLException( > Unknown > Source) > > at > org.apache.derby.impl.jdbc.TransactionResourceImpl.handleException(Unk > nown > Source) > > at org.apache.derby.impl.jdbc.EmbedConnection.handleException(Unknown > Source) > > at org.apache.derby.impl.jdbc.ConnectionChild.handleException(Unknown > Source) > > at > org.apache.derby.impl.jdbc.EmbedResultSet.closeOnTransactionError(Unkn > own > Source) > > at org.apache.derby.impl.jdbc.EmbedResultSet.movePosition(Unknown > Source) > > at org.apache.derby.impl.jdbc.EmbedResultSet.next(Unknown Source) > > at QueryResults$1.hasNext(QueryResults.java:268) > > at DatabasePublisher.process(DatabasePublisher.java:318) > > at java.lang.Thread.run(Thread.java:662) > > Caused by: java.sql.SQLException: Java exception: ': > java.lang.NullPointerException'. > > at > org.apache.derby.impl.jdbc.SQLExceptionFactory.getSQLException(Unknown > Source) > > at > org.apache.derby.impl.jdbc.SQLExceptionFactory40.wrapArgsForTransportA > crossDRDA(Unknown > Source) > > ... 14 more > > Caused by: java.lang.NullPointerException > > at > org.apache.derby.impl.store.access.conglomerate.GenericScanController. > reopenAfterEndTransaction(Unknown > Source) > > at > org.apache.derby.impl.store.access.conglomerate.GenericScanController. > fetchRows(Unknown > Source) > > at > org.apache.derby.impl.store.access.heap.HeapScan.fetchNextGroup(Unknow > n Source) > > at > org.apache.derby.impl.sql.execute.BulkTableScanResultSet.reloadArray(U > nknown > Source) > > at > org.apache.derby.impl.sql.execute.BulkTableScanResultSet.getNextRowCor > e(Unknown > Source) > > at > org.apache.derby.impl.sql.execute.ProjectRestrictResultSet.getNextRowC > ore(Unknown > Source) > > at > org.apache.derby.impl.sql.execute.ScrollInsensitiveResultSet.getNextRo > wFromSource(Unknown > Source) > > at > org.apache.derby.impl.sql.execute.ScrollInsensitiveResultSet.getNextRo > wCore(Unknown > Source) > > at > org.apache.derby.impl.sql.execute.BasicNoPutResultSetImpl.getNextRow(U > nknown > Source) > > ... 6 more > > One more thing I can share is that this seems to also be a timing > problem - if the code is executed slowly, line-by-line in the > debugger, then this problem doesn't occur. But if run at full speed, > then these exceptions are thrown. The problem is not intermittent and > easily reproduced 100% of the time on my end. > > Any thoughts would be greatly appreciated. > > Pavel. > > > > Jefferies archives and monitors outgoing and incoming > e-mail. The contents of this email, including any > attachments, are confidential to the ordinary user of the > email address to which it was addressed. If you are not > the addressee of this email you may not copy, forward, > disclose or otherwise use it or any part of it in any form > whatsoever. This email may be produced at the request of > regulators or in connection with civil litigation. > Jefferies accepts no liability for any errors or omissions > arising as a result of transmission. Use by other than > intended recipients is prohibited. 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