Problem with StatelessSession

kamleshkoringa · **Posted:** Tue Jan 20, 2009 1:21 am

I am using StatelessSession for update/insert large number of data ( more than 100000). In between I am getting Nullpointer exception.

My sample code.

Code:

Session session = sessionFactory.openStatelessSession();
Transaction tx = session.beginTransaction();
ScrollableResults itemCursor =
session.createQuery("from Item").scroll();
while ( itemCursor.next() ) {
   Item item = (Item) itemCursor.get(0);
   Detail details = new Details();
   session.insert(details);
   modifyItem(item);
   session.update(item);
   count++;
   if(count % 100  == 0)
   {
         tx.commit();
         tx = session.beginTransaction();
   }
}
tx.commit();
session.close();

Here I have found that error is in session.insert(details); line.
When I have print error trace it is simple one line

Code:

java.lang.NullPointerException

Here my Hibernate Version is 3.0
Oracle 10g

Please Help..

nordborg · **Posted:** Tue Jan 20, 2009 3:37 am

So what is the complete stacktrace?

It may not be related but... doesn't the call to 'tx.commit()' inside the 'if' statement destroy/closes the itemCursor? I think it would if the cursor lives on the server side but maybe not if the complete results already has been loaded by the client.

kamleshkoringa · **Posted:** Tue Jan 20, 2009 3:49 am

Thanks for reply

Here i have print stack trace. It is noly one line trace. no other information printed in log

Code:

java.lang.NullPointerException

I dont think tx.commit() will close/destroy itemCursor because it is perfactly working with normal session. and I have found error in session.insert(details);

Thanks

nordborg · **Posted:** Tue Jan 20, 2009 3:57 am

Quote:

Here i have print stack trace. It is noly one line trace

This is not a stacktrace. A stacktrace will list the all classes/methods/line number that have been called to reach the code were the error happens. You can print the stacktrace by calling the Exception.printStackTrace() method.

kamleshkoringa · **Posted:** Tue Jan 20, 2009 5:13 am

Thanks for reply

My exception handling code is

Code:

try
{
      // Main code
}
catch (Exception e) 
{
   logger.error("Exception in verify Orders ::",e);
   e.printStackTrace();
   session.getTransaction().rollback();
   throw e; 
}

and i got out put log is

Code:

Exception in verify Orders :: java.lang.NullPointerException

It is strange but I am getting one line stacktrace.

nordborg · **Posted:** Tue Jan 20, 2009 5:54 am

e.printStackTrace() prints to stderr so you have to figure out where this ends up. I don't know which logging implementation you are using. Maybe it can be configured to print the entire stacktrace.

kamleshkoringa · **Posted:** Tue Jan 20, 2009 6:03 am

Thanks for your reply

But I have check stderr.log file in my tomcat and there is one line stacktrace which I have print.

Here I am using log4j and it is printing all stacktrace for other errors.
In this case it is printing one line trace.

Thanks

mmerder · **Posted:** Tue Jan 20, 2009 6:08 am

Do you know, when exactly your error happens? For example after inserting 100 rows?

kamleshkoringa · **Posted:** Tue Jan 20, 2009 6:23 am

Hi
It is totally random and only happen when i am trying to process more than 100000 records. Same error generated after some time from process starts. In my last run error generated after 8512 record processed. I have checked that error is not generated on particular record.

This code is working fine for date when records are 185

Is this any bug of hibernate??

Thanks

nordborg · **Posted:** Tue Jan 20, 2009 7:05 am

Hmmm.... Can this be some memory-related problem? Sometimes when you run out of memory there is not even enough room to create a stack trace and the output will end with a simple one-line error message. I have only seen this as a 'java.lang.OutOfMemoryError'. But maybe it can also take the form of a NullPointerException.

Have you tried to increase the memory? Or decrease it to see if it happens earlier.
You may also want to display some debugging info about the memory usage at regular intervals.

Madan_Prabhu · **Posted:** Tue Jan 20, 2009 7:52 am

hello friend
i think u may go with batch processing.

kamleshkoringa · **Posted:** Tue Jan 20, 2009 8:28 am

HI
Yes I want to do batch processing. I have successfully run this code with normal session. Now I am trying with StatelessSession and wants to compare both performance.

Can any body tell me which way is good for my code.

Thanks

kamleshkoringa · **Posted:** Thu Jan 22, 2009 1:36 am

HI

I have run same code with websphere 6.0 and there is no error. So this error only occurs in Tomcat server.

Here my tomcat configuration.

Tomcat 4.1
JDK 1.4
Hibernate 3.0

Any one have idea why this is not working with TOMCAT.

I have also found that StatelessSession take more time than Normal session with batch processing.

Thanks