Well, @PersistenceUnit annotation has unitName attribute, which is used to idenity the unit specified in persistence.xml.
http://download.oracle.com/javaee/6/api/javax/persistence/PersistenceUnit.html First I would concentrate on the standard way to indentify the units; namely by string names. Later we can think about using annotations. But the current questions is not how to identify the units but whether we want to commit all transactions at once. On Wed, Feb 16, 2011 at 6:02 PM, Josh Canfield <[email protected]>wrote: > Can you do this with marker annotations instead? > @PersistenceUnit > @MyTestUnit > private EntityManager em; > > @PersistenceUnit > @MyOtherUnit > private EntityManager em2; > > @CommitAfter > @MyOtherUnit > @MyTestUnit // commit them both > void onSuccess() {...} > > If you recall Tom van Dijk did a lot of work getting multiple > hibernate sessions to work. Have you looked at his additions? > http://codereview.appspot.com/2896041/ > > There is an email floating around with access to his git repository > and discussing issues of CommitAfter, etc. > > Josh > > On Wed, Feb 16, 2011 at 8:44 AM, Igor Drobiazko > <[email protected]> wrote: > > Hi all, > > > > as you probably know I'm working on the Tapestry/JPA integration. In > > contrast to Tynamo's integration, Tapestry's built-in JPA support will > allow > > having several persistence units in an application. This way you can > inject > > several EntityManagers into a single page, which are connected to > different > > databases. > > > > public class PersistEntity > > { > > @PersistenceUnit(unitName = "TestUnit") > > private EntityManager em; > > > > @PersistenceUnit(unitName = "AnotherUnit") > > private EntityManager em2; > > > > > > @CommitAfter > > void onSuccess() { > > > > ..... > > } > > } > > > > Now I have some issues to apply Tapestry's @CommitAfter semantics to JPA > > resource-local transactions. With Hibernate you have a single Session, so > it > > is clear what to commit when @CommitAfter annotation is present: the > active > > transaction of the single session. With JPA you can have several > > EntityManagers and so several transactions. When @CommitAfter is present, > > you don't know which of the active transactions to commit. > > > > So, the questions is what would be the best solution? Committing all the > > active transactions? Maybe we could add a new attribute to @CommitAfter > > annotations, which expects a list of persistence unit names to commit the > > transactions of? > > > > @CommitAfter( { "TestUnit", "AnotherUnit" } ) > > void onSuccess() { > > > > ..... > > } > > > > > > Any thoughts or ideas`? > > > > -- > > Best regards, > > > > Igor Drobiazko > > http://tapestry5.de > > > > --------------------------------------------------------------------- > To unsubscribe, e-mail: [email protected] > For additional commands, e-mail: [email protected] > > -- Best regards, Igor Drobiazko http://tapestry5.de
