私人 static singleton class 中的最终字段

Question

Are there any consequences declaring/not declaring a field in a singleton class static final or just final if it's private and only a accessible from the class itself?

Answer 1

There are no consequences. Basically singleton is an instance (just one instance) so it is against design to have class member fields (static ones). I would avoid using static fields

Answer 2

The singleton design pattern is to ensure that there is only one instance of your class in the application run-time. This Singleton object it will be used by other object in order to invoke it public methods, so you should expose a public static method to other objects in order to get an instance of the singleton, so the field should be static also.