2.  Obtaining EntityManagers

public EntityManager createEntityManager();
public EntityManager createEntityManager(Map map);

The two createEntityManager methods above create a new EntityManager each time they are invoked. The optional Map is used to to supply vendor-specific settings. If you have configured your implementation for JTA transactions and a JTA transaction is active, the returned EntityManager will be synchronized with that transaction.


OpenJPA recognizes the following string keys in the map supplied to createEntityManager:

The last option uses reflection to configure any property of OpenJPA's EntityManager implementation with the value supplied in your map. The first options correspond exactly to the same-named OpenJPA configuration keys described in Chapter 2, Configuration of the Reference Guide.