Hibernate session fails to query after ConstraintViolationException leading to AssertionFailure

Question

I'm doing a batch processing of records from file in to MySQL through Hibernate. I'm trying to iterate over the records and save them, up on ConstraintViolationException i'm trying to update the record in catch clause. Some how this fails with AssertionFailure Exception.

I'm bounded to use Sessions rather than StatelessSessions.

try {
  System.out.println("Inserting "+key);
  session.save(mud);
} catch(HibernateException cve) {
    cve.printStackTrace();
    //log.error("Failed insert, record already exists: "+key);
    System.out.println("Failed insert, record already exists: "+key);
    List res = session.createQuery("from UserData as ud where ud.taskId = "+taskId+" and ud.userId= "+userId)
        .list();
    System.out.println("Query successfull");
    if (!res.isEmpty()) {
          mud.setId( ((UserData) res.get(0)).getId() );
          session.save(mud);
          continue;
}

}

Here's the StackTrace:

Inserting 463531145008722
org.hibernate.exception.ConstraintViolationException: could not insert: [com.test.www.UserData]
at org.hibernate.exception.SQLStateConverter.convert(SQLStateConverter.java:96)
at org.hibernate.exception.JDBCExceptionHelper.convert(JDBCExceptionHelper.java:66)
at org.hibernate.id.insert.AbstractReturningDelegate.performInsert(AbstractReturningDelegate.java:64)
at org.hibernate.persister.entity.AbstractEntityPersister.insert(AbstractEntityPersister.java:2345)
at org.hibernate.persister.entity.AbstractEntityPersister.insert(AbstractEntityPersister.java:2852)
at org.hibernate.action.EntityIdentityInsertAction.execute(EntityIdentityInsertAction.java:71)
at org.hibernate.engine.ActionQueue.execute(ActionQueue.java:273)
at org.hibernate.event.def.AbstractSaveEventListener.performSaveOrReplicate(AbstractSaveEventListener.java:320)
at org.hibernate.event.def.AbstractSaveEventListener.performSave(AbstractSaveEventListener.java:203)
at org.hibernate.event.def.AbstractSaveEventListener.saveWithGeneratedId(AbstractSaveEventListener.java:129)
at org.hibernate.event.def.DefaultSaveOrUpdateEventListener.saveWithGeneratedOrRequestedId(DefaultSaveOrUpdateEventListener.java:210)
at org.hibernate.event.def.DefaultSaveEventListener.saveWithGeneratedOrRequestedId(DefaultSaveEventListener.java:56)
at org.hibernate.event.def.DefaultSaveOrUpdateEventListener.entityIsTransient(DefaultSaveOrUpdateEventListener.java:195)
at org.hibernate.event.def.DefaultSaveEventListener.performSaveOrUpdate(DefaultSaveEventListener.java:50)
at org.hibernate.event.def.DefaultSaveOrUpdateEventListener.onSaveOrUpdate(DefaultSaveOrUpdateEventListener.java:93)
at org.hibernate.impl.SessionImpl.fireSave(SessionImpl.java:713)
at org.hibernate.impl.SessionImpl.save(SessionImpl.java:701)
at org.hibernate.impl.SessionImpl.save(SessionImpl.java:697)
at com.test.www.CSVToDB.LoadCSVToDB_statelessNoTransaction(CSVToDB.java:92)
at com.test.www.CSVToDB.run(CSVToDB.java:52)
at com.test.www.CSVToDB.main(CSVToDB.java:175)
Caused by: com.mysql.jdbc.exceptions.jdbc4.MySQLIntegrityConstraintViolationException: Duplicate entry '463531-145008722' for key 'taskId'
at sun.reflect.NativeConstructorAccessorImpl.newInstance0(Native Method)
at sun.reflect.NativeConstructorAccessorImpl.newInstance(NativeConstructorAccessorImpl.java:39)
at sun.reflect.DelegatingConstructorAccessorImpl.newInstance(DelegatingConstructorAccessorImpl.java:27)
at java.lang.reflect.Constructor.newInstance(Constructor.java:513)
at com.mysql.jdbc.Util.handleNewInstance(Util.java:411)
at com.mysql.jdbc.Util.getInstance(Util.java:386)
at com.mysql.jdbc.SQLError.createSQLException(SQLError.java:1041)
at com.mysql.jdbc.MysqlIO.checkErrorPacket(MysqlIO.java:4190)
at com.mysql.jdbc.MysqlIO.checkErrorPacket(MysqlIO.java:4122)
at com.mysql.jdbc.MysqlIO.sendCommand(MysqlIO.java:2570)
at com.mysql.jdbc.MysqlIO.sqlQueryDirect(MysqlIO.java:2731)
at com.mysql.jdbc.ConnectionImpl.execSQL(ConnectionImpl.java:2818)
at com.mysql.jdbc.PreparedStatement.executeInternal(PreparedStatement.java:2157)
at com.mysql.jdbc.PreparedStatement.executeUpdate(PreparedStatement.java:2460)
at com.mysql.jdbc.PreparedStatement.executeUpdate(PreparedStatement.java:2377)
at com.mysql.jdbc.PreparedStatement.executeUpdate(PreparedStatement.java:2361)
at org.hibernate.id.IdentityGenerator$GetGeneratedKeysDelegate.executeAndExtract(IdentityGenerator.java:94)
at org.hibernate.id.insert.AbstractReturningDelegate.performInsert(AbstractReturningDelegate.java:57)
... 18 more
Failed insert, record already exists: 463531145008722
org.hibernate.AssertionFailure: null id in com.test.www.UserData entry (don't flush the Session after an exception occurs)
at org.hibernate.event.def.DefaultFlushEntityEventListener.checkId(DefaultFlushEntityEventListener.java:82)
at org.hibernate.event.def.DefaultFlushEntityEventListener.getValues(DefaultFlushEntityEventListener.java:190)
at org.hibernate.event.def.DefaultFlushEntityEventListener.onFlushEntity(DefaultFlushEntityEventListener.java:147)
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:50)
at org.hibernate.impl.SessionImpl.flush(SessionImpl.java:1216)
at com.test.www.CSVToDB.LoadCSVToDB_statelessNoTransaction(CSVToDB.java:98)
at com.test.www.CSVToDB.run(CSVToDB.java:52)
at com.test.www.CSVToDB.main(CSVToDB.java:175)

Answer 1

Looking better (and checking Hibernate code) seems a problem during query.list() (in stacktrace Query successfull is missing) and automatic flush running before query execution. Try change flushMode to COMMIT or do a session.flush() before query.

Do you look at spring-batch for this kind of job?