Re: cast to sub-class or extending instance of super or a.n.other

From:

"Mike Schilling" <mscottschilling@hotmail.com>

Newsgroups:

comp.lang.java.programmer

Date:

Sun, 12 Apr 2009 01:29:03 -0700

Message-ID:

<kDhEl.26829$YU2.25763@nlpi066.nbdc.sbc.com>

Richard Maher wrote:

Hi Peter,

Thanks for the reply.

"Peter Duniho" <NpOeStPeAdM@nnowslpianmk.com> wrote in message
news:op.ur83gavi8jd0ej@macbook-pro.local...

On Sat, 11 Apr 2009 18:10:45 -0700, Richard Maher
<maher_rj@hotspamnotmail.com> wrote:

[...]
As I said this has gotta be easier than this so please put me out
of my misery. What's the best way of "new O = instance of A +
stuff. Then still behave like A in Arrays/Collections) Or is there
something more appropriate
than ArrayList?

Hard to say without knowing exactly what you're trying to do.

Ok, cards on the table: - I have an instance of JSObject; I want to
attach an integer to it (oh, but we must know exactly what that
integer does!) Alright, it's a MinimumMessageNumber; any messages
less than this will be ignored. I want to reference the resultant
object/structure by "index" for performance. The ArrayList (I'm
happy
for alternatives and I'm looking at your hashCode) will normally
contain 1 element, and max-out at about10. The minMsgNum is an
appendage/baggage something that I'm sure there's a flash OO term
for
like "orthogonal" that'll give everyone a boner (see, I've been
drinking :-)

Turn things around: create a MessageObject that contains two fields:

1. You minimum message number
2. A reference to your JSObject
MessageObject can also delegate some methods to the JSObject, if
that's convenient.

Make your ArrayList a List or MessageObjects.

If you need them sorted, use a TreeSet instead of an ArrayList and
define MessageObject.compareTo() appopriately.