Static Nested Classes

Static nested classes

As with class methods and variables, a static nested class is associated with its outer class. And like static class methods, a static nested class cannot refer directly to instance variables or methods defined in its enclosing class: it can use them only through an object reference.
They are accessed using the enclosing class name.

OuterClass.StaticNestedClass

For example, to create an object for the static nested class, use this syntax:

OuterClass.StaticNestedClass nestedObject =
     new OuterClass.StaticNestedClass();

// Java program to demonstrate accessing // a static nested class // outer class class OuterClass {     // static member     static int outer_x = 10;           // instance(non-static) member     int outer_y = 20;           // private member     private static int outer_private = 30;           // static nested class     static class StaticNestedClass     {         void display()         {             // can access static member of outer class             System.out.println("outer_x = " + outer_x);                           // can access display private static member of outer class             System.out.println("outer_private = " + outer_private);                           // The following statement will give compilation error             // as static nested class cannot directly access non-static membera             // System.out.println("outer_y = " + outer_y);                   }     } } // Driver class public class StaticNestedClassDemo {     public static void main(String[] args)     {         // accessing a static nested class         OuterClass.StaticNestedClass nestedObject = new OuterClass.StaticNestedClass();                   nestedObject.display();               } }

Output:

outer_x = 10
outer_private = 30