他们在Java中是否具有相当于C＃的静态类？

Question

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. :)

Answer 1

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.

Answer 2

No. Just mark everything static. Possibly add a private constructor that throws an error and make the class final .

Answer 3

public class Util
{
    // final prevents inheritance, just like C# static classes can't be inherited
    // final is basically like the C# sealed keyword.
    public static final class Math
    {
        // prevent constructor from being called
        private Math(){}
        static
        {
            // Acts like a C# static constructor. (only runs once, )
        }
        public static int Add(int num1, int num2)
        {
            return num1+num2;
        }
    }
}

Answer 4

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.