Question

I use OpenJPA on WebSphere Application Server.
My WebApplication uses JSF 2 (without EJB).

I wanted to know if there are best practices how to use JPA in JSF.

I found that the EntityManagerFactory (EMF) should be application scoped.
Also the EMF should be (only) destroyed when the application stops.

But my sources are not the newest:

Java Notepad: JPA EMF in web applications from 2007

Best way to use JPA in web-tier from 2010

How to close a JPA EntityManger in web applications
from 2007

Are there other practices or better ways to handle JPA in JSF?
Especially Scope of EMF and DAO.

Best Regards, Veote

Answer 1

Create a simple servlet filter which creates the EMF in init() method, closes it in destroy() method and creates an EntityManager in doFilter() method which get set as a ThreadLocal<EntityManager>. You can also begin and end the transactions in there.

This is also known as the “open session in view” or “open entitymanager in view” pattern.