Squee wrote:
Well, I'd have to go look at the code again to be fully sure, but we
have a client layer built on top of MINA for the GUI part of our app,
where we pull a ton of data from a remote server for viewing. When a
GUI element needs data for its local cache, it creates a "DataChannel"
object which performs the necessary connections with MINA.
Why don't you use a Connector for that ?
It then
synchronously waits for the session to connect before continuing.
The Connector is just handling that for you ...
The
DataChannel class is a SingleSessionIoHandler implementation, and our
IoHandler is a SingleSessionIoHandlerDelegate. Each DataChannel
subclass provides different IoHandler functionality (same protocol,
different roles and data to manage).
Why not using a Connector for each protocol ?
This allows us to have completely different handlers for the different
data caches, while still using the same protocol messages for each
cache. (i.e. a response from the server to clear the local cache is
exactly the same, but handled differently depending on the data) This
is preferable in this instance over the demuxing for this reason, as
well as the encapsulation that having all of our data handling on our
DataChannel IoHandlers helps with.
The biggest problem I had with it was that I had to subclass
SingleSessionIoHandlerDelegate to allow us to use our already created
DataChannel class (again, an implementation of
SingleSessionIoHandler), rather than creating them AFTER the session
was created, but that's probably very specific to our way of using it.
Basically, our version doesn't use the factory and sets the session on
an existing specified SingleSessionIoHandler when the session is
created.
IMO, the 'multiton' pattern is not the best pattern ever. It's just a
Hashmap containing many singleton. I don't see any advantage of having
such a pattern implemented in MINA core.
I don't mean that what you do is bad, Squee, what I just want to stress
is that it's more or less the application designer to decide what to do
with established connections, but it's not MINA responsability to
implement any existing patterns.
So, my question is : how hard would it be to switch to a multiton
pattern to a simple map of Connectors ?
--
--
cordialement, regards,
Emmanuel Lécharny
www.iktek.com
directory.apache.org
