I actually think that's exactly why the visitor pattern is nice -- the
more transports you have, the better it gets because you can elegantly
deal with the additional types rather than resorting to instansofs.
The double-dispatch method calling is also a bigger performance boost
the more types you have (as opposed to more "else if"s with the
instanceof approach).
A visitor itself can also do all sorts of things other than just
identify the type.
That said, it's really a cosmetic difference either way and barely
worth the discussion -- your time is certainly better spent elsewhere!
-Adam
On Feb 13, 2008 11:58 AM, 이희승 (Trustin Lee) <[EMAIL PROTECTED]> wrote:
> I am not sure if it's a more flexible solution considering we are going
> to have more transports. For example, we have serial port communication
> transport, and we will have to add a visit method per each transport.
>
> Trustin
>
> 2008-02-13 (수), 09:58 -0500, Adam Fisk 쓰시길:
>
> > This would be a nice place for the good old visitor pattern, so
> > something like, in SocketSession,
> >
> > SocketSession implements VisitableSession
> >
> > ...
> > public void accept(final SessionVisitor visitor)
> > {
> > visitor.visitSocketSession(this);
> > }
> >
> > Then you have a lot of flexibility with the visitor itself to handle
> > types nicely. The SessionVisitor would be an interface like:
> >
> > public interface SessionVisitor
> > {
> > void visitSocketSocket(final SocketSession session);
> > void visitDatagramSession(final DatagramSession session);
> > }
> >
> > I'd be happy to make a patch along those lines if people were
> > interested. It would use generics for return types rather than the
> > above for slightly more flexibility.
> >
> > -Adam
> >
> >
> > On Feb 13, 2008 12:06 AM, 이희승 (Trustin Lee) <[EMAIL PROTECTED]> wrote:
> > > 2008-01-28 (월), 10:47 -0400, Brenno Hayden 쓰시길:
> > > > Hello ,
> > > > i have same doubt..
> > > > - How can I tell if the connection is udp or tcp?
> > >
> > > In 1.x, you can use IoSession.getTransportType(). In 2.x, you can
> > > simply use 'instanceof SocketSession' or 'instanceof DatagramSession'.
> > >
> > > --
> > > what we call human nature is actually human habit
> > > --
> > > http://gleamynode.net/
> > >
> >
> >
> >
> --
> what we call human nature is actually human habit
> --
> http://gleamynode.net/
>
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