Re: Design Patterns

From:

=?ISO-8859-1?Q?Arne_Vajh=F8j?= <arne@vajhoej.dk>

Newsgroups:

comp.lang.java.programmer

Date:

Tue, 05 Feb 2013 20:11:07 -0500

Message-ID:

<5111adac$0$284$14726298@news.sunsite.dk>

On 2/5/2013 1:20 PM, Eric Sosman wrote:

On 2/5/2013 12:51 PM, Stefan Ram wrote:

Eric Sosman <esosman@comcast-dot-net.invalid> writes:

Maybe someone can come up with an SCSE where a singleton is needed.

Runtime.getRuntime().exit(0);

   The library (Java SE) could have been defined to allow:

class Main
{ public static void main( final java.lang.Runtime runtime )
   { runtime.println( runtime.getArgc() + " command-line arguments." );
     runtime.exit(); }}

   or - with less changes to the current state of Java - to allow:

Runtime.exit( 0 );

A singleton class can be transformed into an uninstantiable
class having only static methods. An uninstantiable class with
only static methods can be transformed into a singleton class.
The two designs are duals: Why should one be deprecated and the
other preferred?

I would in most cases with more serious code prefer singleton
due to its interface capability.

For throw away code I would probably go for the static just
because I am a lazy bastard.

If all-static vs. singleton is the most pressing problem
someone faces, he has an easy life indeed!

I agree with that.

Arne