I have Hibernate entity that I have to convert to JSON, and I have to translate some values in entity, but when I translate values, these values are instantly saved to datab
You can detach an entity by calling Session.evict().
Other options are create a defensive copy of your entity before translation of values, or use a DTO instead of the entity in that code. I think these options are more elegant since they don't couple conversion to JSON and persistence layer.