How dos the application will know the path of persistence.xml file

[Ravi Kiran Va]

Hi ,

I am seeing examples for ConatierManaged EntityManager

@PersistenceContext 
public class Test extends HttpServlet

{

public void doGet()
{
EntityManager em
// JnDI Lookup code 

em = (EntityManager) ctx.lookup("java:comp/env/persistence/em");
em.persist(Employee)
}

Inside web.xml file :

<web-app> 
<persistence-context-ref> 
 <persistence-context-ref-name>persistence/em</persistence-context-ref-name>
  <persistence-unit-name>my-pu</persistence-unit-name>
</persistence-context-ref>
</web-app>

Please tell me how the Application will know the path of persistence.xml file .

Thank you for reading

[Jaikiran Pai]

The possible locations of the persistence.xml is pre-defined by the JPA spec. But the user application does not need to know the location of the persistence.xml. It's upto the persistence provider (like Hibernate) to search and find the persistence.xml in appropriate locations.