Re: Can this callback mechanism be generified?

From:
Mark Space <markspace@sbc.global.net>
Newsgroups:
comp.lang.java.help
Date:
Mon, 05 May 2008 21:23:44 -0700
Message-ID:
<s3RTj.312$8i5.232@flpi144.ffdc.sbc.com>
Casper Bang wrote:

Mark Space wrote:

In fact that might be the first thing I do in a real program, make a
new object that is also it's own callback. No sense in proliferating
objects.

public class EmployeeInfo
    implements Serializable,
               Cloneable,
               CallBack<EmployeeInfo>,
               Compareable<EmployeeInfo>
{


Right, that use case should be covered. It's rarely practiced in my
experiences), because often you need to implement an interface more than
once, which of course you can't - in spite of having apparent different
signatures which dispatches to two distinct callback methods:

public class Formatter implements Callback<Date>, Callback<String>
...
Error: Repeated interface

/Casper


That's not what I meant. Unless I'm totally confused here, you look for
interface[0]. Which may or may not be the Callback interface. It could
be some other interface at index 0.

Now maybe you know this and were just doing as you say a quick mock up,
but I wanted to be clear.

Two parameterized interfaces of the same type aren't possible of course,
since erasure means that you've declared the same interface twice.
That's totally not what I show above, but again maybe you're already
ahead of me here.

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