HibernateJpaDialect.java 文件源码

@Override
public Object prepareTransaction(EntityManager entityManager, boolean readOnly, String name)
        throws PersistenceException {

    Session session = getSession(entityManager);
    FlushMode flushMode = session.getFlushMode();
    FlushMode previousFlushMode = null;
    if (readOnly) {
        // We should suppress flushing for a read-only transaction.
        session.setFlushMode(FlushMode.MANUAL);
        previousFlushMode = flushMode;
    }
    else {
        // We need AUTO or COMMIT for a non-read-only transaction.
        if (flushMode.lessThan(FlushMode.COMMIT)) {
            session.setFlushMode(FlushMode.AUTO);
            previousFlushMode = flushMode;
        }
    }
    return new SessionTransactionData(session, previousFlushMode);
}