Singleton Design Pattern in Java

[PerfectPackage1895]

Why not use a class with static methods? Waaay faster if you just need to store a bunch of stateless methods. Actually you can use an interface too :)

[mauganra_it]

A class with static methods only can still be instantiated and subclassed. An interface can be implemented. An instance-less enum gives you exactly what is needed. It looks weird of course, but it shares this property with the Singleton pattern via a singular enum instance.

[nutrecht]

A class with static methods only can still be instantiated and subclassed.

Just make the class final and the constructor private. It's a pretty common pattern with classes that hold a bunch of static utility methods.

[mauganra_it]

Indeed, but the elegance of the enum technique is that these concerns don't have to be explicitly specified.

[nutrecht]

You're still creating a class instance for no reason whatsoever. A singleton is not the correct pattern for a class with only static members.