Hi.

I recently migrated an API service of mine from Hibernate 3.6.7 to Hibernate 4.1.7.
Now, I get the following exception very frequently
org.hibernate.TransactionException: nested transactions not supported
at org.hibernate.engine.transaction.spi.AbstractTransactionImpl.begin(AbstractTransactionImpl.java:152)
at org.hibernate.internal.SessionImpl.beginTransaction(SessionImpl.java:1392)

The exception happens randomly on some APIs but doesn't get reproduced every time. The exception is intermittent.

I made sure to use one single transaction for a function and not creating a nested transaction anywhere in my code. Following is a sample code snippet where the exception happens sometimes :

@Override
public ApiResponse<BaseModel> getLanguages() {
List<BaseModel> result = null;
Integer total;
Transaction trans = null;
try {
trans = dictionaryDao.beginTransaction();
total = dictionaryDao.getLanguagesCount().intValue();
List<LanguageMaster> languageDOList = dictionaryDao.getLanguages();
result = new ArrayList<BaseModel>();
result = format(languageDOList);
trans.commit();
} catch (RuntimeException e) {
if (trans != null)
trans.rollback();
throw e;
}
return getResponse(result);
}

The function dictionaryDao.begintransaction is defined as below :

public Transaction beginTransaction() {
getCurrentSession().setFlushMode(FlushMode.COMMIT);
Transaction t = getCurrentSession().beginTransaction();
return t;
}

The exception occurs while beginning the transaction in dictionaryDao.begintransaction at Transaction t = getCurrentSession().beginTransaction();.

We are using BoneCP as the connection pool provider.

Can someone provide any help on how to get around this random error ?

Thanks,
Rajat