Question

I am getting this strange error sometimes while my thread executes. What could this be related to?

2011-Jun-25 09:05:22,339 ERROR AssertionFailure:45 - an assertion failure occured (this             may indicate a bug in Hibernate, but is more likely due to unsafe use of the session)
org.hibernate.AssertionFailure: null id in com.inrev.bm.bean.IRKeyWordTweet entry (don't flush the Session after an exception occurs)
    at         org.hibernate.event.def.DefaultFlushEntityEventListener.checkId(DefaultFlushEntityEventListener.java:78)
at org.hibernate.event.def.DefaultFlushEntityEventListener.getValues(DefaultFlushEntityEventListener.java:187)
at org.hibernate.event.def.DefaultFlushEntityEventListener.onFlushEntity(DefaultFlushEntityEventListener.java:143)
at org.hibernate.event.def.AbstractFlushingEventListener.flushEntities(AbstractFlushingEventListener.java:219)
at org.hibernate.event.def.AbstractFlushingEventListener.flushEverythingToExecutions(AbstractFlushingEventListener.java:99)
at org.hibernate.event.def.DefaultFlushEventListener.onFlush(DefaultFlushEventListener.java:49)
at org.hibernate.impl.SessionImpl.flush(SessionImpl.java:1028)
at org.hibernate.impl.SessionImpl.managedFlush(SessionImpl.java:366)
at org.hibernate.transaction.JDBCTransaction.commit(JDBCTransaction.java:137)
at com.inrev.bm.streaming.IRKeyWordStreaminThread.run(IRKeyWordStreaminThread.java:119)

My code for inserting,

    Transaction tx = null;
    Session session = sessionFactory.openSession();
    tx = session.beginTransaction();

    int count = 0;
    try
    {
        for (Iterator itrList = statusToInsert.iterator(); itrList.hasNext();) 
        {
            try 
            {
                IRecord record = (IRecord) itrList.next();
                session.save(record);
                count++;
                if ( count % 10 == 0 ) 
                { 
                    session.flush();
                    session.clear();
                    tx.commit();
                    tx = session.beginTransaction();
                }

            }
            catch (Exception e) 
            {
                tx.commit();
                session.close();
                session = sessionFactory.openSession();
                tx = session.beginTransaction();
                StringWriter sw = new StringWriter(); 
                PrintWriter pw = new PrintWriter(sw); 
                e.printStackTrace(pw); 
                log.error(sw.toString());
            }
        }
    }
    catch (Exception e) {
        StringWriter sw = new StringWriter(); 
        PrintWriter pw = new PrintWriter(sw); 
        e.printStackTrace(pw); 
        log.error(sw.toString());
    }
    finally {
        tx.commit();
        session.close();
    }

Regards,

Rohit

Answer 1

The problem is that your code is handling an Exception, which is a bad, bad thing to do in 99.9% of the cases, and the following is happening:

One of the interactions with the session fails in the try block, and throws an exception. When this happens, the session is invalidated and cannot be used for absolutely anything as it’s in an inconsistent state. But your code interacts with the session in the catch block, which triggers the assertion.

The only safe thing to do after an exception with the session, is to rollback the transaction and close it. Any other type of interaction will probably generate another exception (in this case an assertion exception).