eclipselink - JPA - Is there a way/method to retrieve Persistence Unit information

Question

I'd like to find out my data source name in the code. Is there a way of doing that? I am using eclipselink.

thanks To be more specific, my aim is to get an jdbc connection object. I know i can do that thru:

datasource = (DataSource) (new InitialContext()).lookup("my_data_source_name")
connection = dataSource.getConnection();

But I don't want to hard code the data source name in my code.

I also tried

java.sql.Connection connection = em.unwrap(java.sql.Connection.class);

and it always return null.

Answer 1

.unwrap() should be the way to go, as written in EclipseLink wiki.

I also used to get null when calling em.unwrap(java.sql.Connection.class); because it was not inside a transaction. When called like this:

em.getTransaction().begin();
java.sql.Connection conn = em.unwrap(java.sql.Connection.class);
// ...
em.getTransaction().commit();

everything works fine!