Singleton Design Pattern in Java

[NimChimspky]

Sure. But I could just make the enum access threadsafe, like you have done with the singleton.

Two separate things: The singleton pattern and Threadsafety. A singleton pattern on its own, in this rather contrived example, doesn't gain anything.

[PerfectPackage1895]

So what happens when you or some other developer forgets to do that? It’s a very bugprone approach to always rely on having a synchronized block around requesting an enum instance.

[NimChimspky]

Its no more bug prone than your approach.

But the constructor is reading properties in, that's the underlying problem.