JPA EntityManagerFactory with persistence.xml and Properties Map

Question

Can I pass some properties to an EntityManagerFactory by code, while still maintaining persistence.xml as the main configuration source? Using createEntityManager's overload with a Map appears to override persistence.xml completely:

Map<String, String> propertyMap;
factory.createEntityManager(propertyMap);

I'd like to configure JPA in persistence.xml, but pass in a custom connection string. I'm using HSQL and I'd like to compose a custom DB-file path with the current user directory, which I have to get by code (as far as I know).

It would be great if I could keep persistence.xml anyway, as I'd not have to write a custom configuration mechanism.

I would load the properties from persistence.xml, replace/add the desired values and create the entitymanager from the properties. — SJuan76, May 17 '12 at 08:32

DataNucleus · Accepted Answer · 2012-05-17T10:07:19.820

3

You mean

Persistence.createEntityManagerFactory(puName, props);

unless of course you mean you have created the EMF first and want to apply props after that?

edited May 17 '12 at 10:07

answered May 17 '12 at 08:54

DataNucleus

15,497
3
32
37

Great hint, did not think of creating the factory differently. Seems to work. Thank you! – Matthias Meid May 17 '12 at 10:13

JPA EntityManagerFactory with persistence.xml and Properties Map

1 Answers1