Static Class in Java

There is no top level static class.

You can only create static nested class in Java. And it is treated as a top-level class.

Since it's a static member of enclosing class, it can access all static members in enclosing class.

Defined like this:

public class OuterClass{
public static class StaticNestedClass{
//variable
//method
}

public class InnerClass{
//access even private members of OuterClass

}
}

Name of Inner class was given to non-static class of OuterClass.

Local class is the one defined inside method.

Anonymous class is the one created from interface.

Instantiate static nested class. Each instance is itself a single instance. Do not be fulled by static keyword here. static here means this is a static member of OuterClass, when using it, it is treated as top-level class.

OutClass.StaticNestedClass snc1 = new OutClass.StaticNestedClass();
OutClass.StaticNestedClass snc2 = new OutClass.StaticNestedClass();

Inner class has to be instantiated from instance of OuterClass.

OuterClass oc = new OuterClass();
OuterClass.InnerClass ocic = oc.new OuterClass.InnerClass();

Instantiate anonymous class

Interface Service {
//some code
}

Service s = new Service(){
//code to implement inteface methods
}