Hi Mike,
Unlike ORMs, we need to provide the XAResource instances to the app server
(which in turn are associated with our internal connections to the database
server)
But I guess, if the user just sees a DataSource, then that will be an app
server proxy which eventually delegates to the XADataSource of
our "JDBC" driver (provided I configure a DataSource that returns enlisted
connection in the app server using our JDBC driver)
So my pseudo-code assumption of the app servers DataSource proxy is like
this:
public class ContainerDataSourceProxy implements DataSource {
XADataSource xaDs = ...; //XADataSource of the installed JDBC driver
for this pool
public Connection getConnection() throws SQLException {
XAConnection xaCon = xaDs.getXAConnection();
enlist(xaCon.getXAResource());
return xaCon.getConnection();
}
...
}
So we could simply call getConnection() (and not using the returned value
at all) to trigger the app servers
enlisting our XAResource.
Regards,
Christian
On Fri, May 11, 2012 at 3:14 PM, michael keith <michael.keith_at_oracle.com>wrote:
> Hi Christian,
>
> The data source referenced by the jta-data-source name is a DataSource
> provided by the container in JNDI. It is the same one that any application
> could look up and use, hence it is a javax.sql.DataSource.
>
> XADataSource is an internal type used by the driver and container to
> coordinate XA, but users of the data source are not expected to participate
> at that level. The JPA provider acts like a client of the data source,
> using its connections to read and write, so it does not need to be aware of
> the XA protocol being implemented underneath.
>
> Hope this makes things clearer.
>
> Regards,
> -Mike
>
>
> On 10/05/2012 7:50 AM, Christian Romberg wrote:
>
> Hello,
>
> It is not explicitly mentioned in the spec, but I guess I can safely
> assume, that the data source denoted by
> jta-data-source is of type "javax.sql.XADataSource"?
>
> After the JPA implementation has obtained an XAConnection from this
> XADataSource, is it expected to
> to do any calls (and if so, in any specific order) on this XAConnection?
>
> E.g. is it necessary, to call XAConnection.getConnection() to trigger that
> the app server calls XAConnection.getXAResource()
> on the very same XAConnection? Or is it sufficient to just call
> "XADataSource.getXAConnection()" to trigger this?
>
> (Some background: we don't use JDBC connections (being not an ORM) and
> probably we would need to provide our own
> XADataSource implementation, so that the app server picks up our own
> XAResource implementation)
>
> Thank you!
>
> Christian
>
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> Christian Romberg
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54723, Amtsgericht Hamburg. Registered Office: Halenreie 42, 22359
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NOTICE: This e-mail message, including any attachments, is for the sole
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