Spring + Hibernate - when the transaction is really committed? - spring

Question

I'm facing a singular problem...
I need to update an entity, but i don't know when it is really updated
My method is
#Override
#Transactional(isolation = Isolation.SERIALIZABLE)
public void lightOn(int idInterruttore) {
Interruttore interruttore = dao.findById(idInterruttore);
String inputPin = interruttore.getInputPin();
String pinName = interruttore.getRelePin();
GpioController gpio = interruttore.getGpio();
GpioPinDigitalOutput rele = gpio.provisionDigitalOutputPin(RaspiPin.getPinByName(pinName));
try {
DateTime date = new DateTime();
Date now = date.toDate();
int i = 1;
while (getInput(inputPin, gpio) != 1) {
if(i > 1){
logger.debug(String.format("Try n %s", i));
}
pushButton(rele);
Thread.sleep(1000);
i++;
}
dao.updateInterruttore(idInterruttore, now, true);
} catch (GpioPinExistsException | InterruptedException gpe) {
logger.error("GPIO già esistente", gpe);
} finally {
gpio.unprovisionPin(rele);
}
logger.debug(String.format("After the update status should be true and it's %s",
interruttore.isStato()));
}
updateInterruttore is (i used this form to be sure to call the commit after the update... I have the lock Option because multiple call can be done to this method but only the first must update
#Override
public void updateInterruttore(int idInterruttore, Date dateTime, boolean stato) {
Session session = getSession();
Transaction tx = session.beginTransaction();
String update = "update Interruttore i set i.dateTime = :dateTime, i.stato = :stato where idInterruttore = :idInterruttore";
session.createQuery(update).setTimestamp("dateTime", dateTime).setBoolean("stato", stato)
.setInteger("idInterruttore", idInterruttore).setLockOptions(LockOptions.UPGRADE).executeUpdate();
tx.commit();
}
}
Well... when I update the log says me:
After the update status should be true and it's false
This happens only the first time I call the method, the second time interruttore.isStato is correctly true.
Why this happens?

Answer 1

This happens because you're updating the database directly with the update statement. Hibernate does not update automatically an already loaded entity in this case. If you reload the entity after the call to dao.updateInterruttore you should get the updated data.

Answer 2

Two notes:
1) You are using a query to apply the update. In that case, Hibernate will no update the entity that is in the session. Unless you update the entity itself and call session.save(interruttore), then the entity will not be updated. (But the update shows up in the DB.) Furthermore, I don't understand why you just don't update the entity and save it via session.save().
2) You are annotating the service method with #Transactional. (Assuming that's Spring annotation) If you use JTA, your tx.commit() will have no effect. But once the method completes, your transaction is committed. (or rolled back if the method throws an exception) If you are not using JTA, then get rid of #Transactional and manage transaction in your DAO method, as you are doing. But that's considered bad practice.