[Please take this constructively despite my string words] Arg. As much as I love Effective Java and admire Joshua Bloch, this one feels like a brain fart, and Block even concedes this pattern "may feel a bit unnatural", no kidding. This is an ENUM, but it does NOT enumerate ANYTHING. It is only used as a hack to avoid defining a private ctor. The falls for me in the same category as defining constants in interfaces when interfaces should be used to define contracts.
To make things worse, this enum does not even follow the pattern documented in Effective Java because it does not define an INSTANCE enum value! For me, this definitely violates the principle of least surprise :-( Sorry to pile on... but also: Why is this type even public? I suppose I only have myself to blame for not reviewing the original commit ;-) but I am reviewing now ;-) Gary On Tue, Nov 17, 2020 at 3:59 PM Carter Kozak <[email protected]> wrote: > I'm a big fan fan of enum singletons. This case looks like an enum with no > values for utility methods to avoid a private ctor, I haven't used enums > this way myself. I think the trade-off is between avoiding having to write > a private constructor to prevent extension, and the downside of enum static > methods e.g. Uris.values(), Uris.valueOf(String), > Uris.valueOf(Class,String) which could be argued violate the principle of > least astonishment. I don't have much of an opinion on enum utility methods. > > On Tue, Nov 17, 2020, at 15:48, Volkan Yazıcı wrote: > > I use enums for singletons, which is the recommended way to create > > singletons in Effective Java by Joshua Bloch. Given I have used it in > some > > other places as well and heard no complaints so far, I did not convert > them > > to a final class with a private ctor. Should I? > > > > On Tue, Nov 17, 2020 at 9:25 PM Gary Gregory <[email protected]> > wrote: > > > > > Hi all, > > > > > > Why is this an enum and not a class? > > > > > > Gary > > > > > >
