jpa - How to get DataSource or Connection from JPA2 EntityManager in Java EE 6

Question

I have a working application where I use Java EE 6 with EclipseLink for persistence and a PostgreSQL database.

For the User-Registration I want to set the password in PostgreSQL to:

... password = crypt('inputPassword',gen_salt('bf')) ...

As I cant use DigestUtils for this, I have to insert the user manually into the DB. To keep my application configurable I do not want to query the DataSource with an InitialContextInstance.lookup(dataSource) but to extract it (or the Connection) somehow from the EntityManager like:

DataSource ds = entityManagerInstance.someFunctionThatReturnsADataSourceOrConnection();

Or would it be possible to use createNativeQuery or something similar in conjuntion with a prepared statement to protect against injections?

Answer 1

sometimes it just takes another run in google:

entityManager.getTransaction().begin();
java.sql.Connection connection = entityManager.unwrap(java.sql.Connection.class);
...
entityManager.getTransaction().commit();

as described in the Eclipse Link Documentation