JAVA

use of nested class in java

In Java, it is possible to define a class within another class, such 
classes are known as nested classes. They enable you to logically group 
classes that are only used in one place, thus this increases the use of 
encapsulation, and creates more readable and maintainable code.

Java Nested Static Class

Class Animal {
   static class Mammal {
      // static and non-static members of Mammal
   }
   // members of Animal
}

nested class in java 8

A regular nested class cannot access members of its outer class. But a nested class marked as an inner class can.

Java Static Nested Class

OuterClass.NestedClass obj = new OuterClass.NestedClass();