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Why you never close the EntityManager in yours dao’ s implementation?
Wo close the jdbc connection in a Resource-Local environment?Thanks,
MarcoMarco,
I’ve never seen a document that suggested you close the EM between invocations, I believe that would be a very expensive operation. Do you have a doc you are referencing that suggests that?In the ejb-3.o specification – page 120 – you’ll find an example. Usually i use hibernate as persistence library, and i have to close the hibernate session (witch close the jdbc connection).
In JPA i don’t understand who close the resources, in particular the jdbc connection. Or, using a connection pooling, who return the jdbc connection object to the pool.Thank for your reply,
MarcoAnother example; take a look at the book “Java Persistence with Hibernate” – Manning in the JPA examples.
Marco
In JPA i don’t understand who close the resources, in particular the jdbc connection. Or, using a connection pooling, who return the jdbc connection object to the pool.
The application server takes care of all of this as long as you use a JNDI-bound data source. When working with an app server it is generally suggested you do just that.
“Managed entity instances are monitored. Every modification you make to an
instance in persistent state is at some point synchronized with the database
(unless you abort the unit of work). Because the EntityTransaction is managed
by the application, you need to do the commit() manually. The same rule applies
to the application-controlled EntityManager: You need to release all resources by
closing it” – from Java Persistence with Hibernate [Christian Bauer, Gavin King].What do you think?
