--- Erik Price <[EMAIL PROTECTED]> wrote:
>
>
> David Graham wrote:
>
> > Static methods are evil for many reasons including philosophical
> (they're
> > not OO) and practical (you can't override their behavior). You should
> use
> > a Singleton class with non-static methods.
>
> And the generally accepted way to get a reference to the singleton is
> with a static "getInstance" method, right?
Yep, that's the one use case that I accept the use of static methods :-).
> Is there any way to make an
> anonymous subclass of a Singleton that uses a static method to get the
> instance? For example:
>
>
> public class SubclassSingleton {
>
> public static void main(String[] args) {
> MySingleton ms = new MySingleton() {
> int doSomething() {
> return 42;
> }
> }
>
> MySingleton inst = ms.getInstance();
> System.out.println(ms.doSomething());
> }
> }
>
> class MySingleton {
>
> static MySingleton me;
>
> static getInstance() {
> if (MySingleton.me == null)
> MySingleton.me = new MySingleton();
>
> return MySingleton.me;
> }
>
> int doSomething() {
> return 8;
> }
> }
>
>
>
> This simple code doesn't work, because even if you subclass the
> singleton and override one of the methods, the getInstance() method will
>
> create a base-class MySingleton. And since this method is static, it
> can't be overridden. So while singletons are useful, you can't use them
>
> in anonymous subclasses (as far as I can tell), which makes them
> difficult to use with mock object unit testing.
The AbstractFactory and FactoryMethod patterns are applicable in this
situation.
David
>
> Please someone point out the flaw in my reasoning, it has bothered me
> for quite a while and I'd love to be proven wrong.
>
>
>
> Erik
>
>
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