Do they have the equivalent of C# static classes in Java?
I want to create a C# static class but in Java, how do I do it?
Thanks for the help.
EDIT: Thanks for the help guys. :)
+5
A:
No. Just mark everything static. Possibly add a private constructor that throws an error and make the class final.
Tom Hawtin - tackline
2009-10-02 20:31:35
I've never tried this, but what happens if you try to mark the class as final and abstract?
R. Bemrose
2009-10-02 20:33:17
It can't be both `final` and `abstract`, unfortunately. But good point.
Tom Hawtin - tackline
2009-10-02 20:36:28
You'd get a compile time error.
RichardOD
2009-10-02 20:37:01
Interesting note: C# static classes are abstract and sealed. No need for a private constructor.
Snarfblam
2009-10-02 20:50:10
@Snarfblam: And the compiler stops you from trying to use it as if you could ever have an instance (e.g. you can't use it as a parameter type). No such benefits in Java, unfortunately :(
Jon Skeet
2009-10-02 21:03:23
Prefer this to the accepted answer just coz of the additional detail on final and private constructor.
serg10
2009-10-07 11:10:01
+8
A:
There are static members in Java classes, but no static class, like in C#.
The C# static class modifier doesn't really change anything about the class, from a usage standpoint, though. It just prevents you, at compile time, from adding instance variables.
You can make a class in Java that would work like a C# static class by just declaring every member as static. See the tutorial section on "Understanding Instance and Class Members" for details.
Reed Copsey
2009-10-02 20:33:32
Yeap in .NET 1.1 I remember creating a sealed class with a private constructor to achieve the desired effect.
RichardOD
2009-10-02 20:38:20
It also prevents you at compile time from adding instance methods, operator overloads or `new` expressions that would allocate an instance of the class.
Daniel Earwicker
2009-10-02 20:39:45
+1
A:
In every OO language,a good (an more flexible) alternative to static class declaration is to use the singleton pattern.
However, if your class is a pure utility class, you can declare all your members/methods as static.
dweeves
2009-10-02 20:35:39
if the solution to a problem is to add a singleton, now you've got two problems...
Rich Seller
2009-10-02 20:42:05