Changing to users again...
On Tue, Mar 17, 2015 at 10:38 AM Nigel Deakin <nigel.deakin_at_oracle.com>
wrote:
> On 17/03/2015 12:31, John D. Ament wrote:
> > I think using a service loader approach would be the best, and most
> consistent option.
> >
> > ConnectionFactory cf = JMS.newConnectionFactory(map);
> >
> > or
> >
> > ConnectionFactory cf = JMS.newConnectionFactory();
> >
> > Where JMS is a new class added by the EG, similar to provider classes in
> WebSocket, JPA, BeanValidation etc.
> >
> > John
>
> Who implements the "JMS" class? Does each JMS provider have to supply its
> own implementation?
>
>
The JMS provider implements it. The most common approach is a service
loader, leveraged by CDI, Bean Val, WebSocket. Less common is a factory
like EJBContainer. JPA has their own thing entirely based on a custom file
entry.
> If it is implemented by the JMS provider, how how does the application
> choose which whose implementation of the "JMS"
> class it wishes to use, bearing in mind that the same application must be
> able to use multiple JMS providers?
>
>
ServiceLoaders. If you have multiple impls on the path, an option like
JPA's is possible, or adding a map of options to look for would help.
> If the same implementation is expected to work for each JMS provider, then
> how does the implementation know how to
> instantiate a given ConnectionFactory?
>
They're generally no args constructors with init methods.
>
> Nigel
>