Static class in java

• Yes we can create a class as static. But class should be inner class or nested class.
• We know how to create static methods, static variables and static blocks.
• As Java Supports defining a class within a class we can create a static inner class inside a class.
• This inner static class inside a class can access static members of outer class even its private.

Java Program to create static inner class:

1. package instanceofjavaTutorial;
2.  
3. public class Outer{ 
4.  
5.   static class inner{
6.  
7. public void print(){
8.  
9. System.out.println("static inner class method called");
10.  
11. }
12.  
13. }
14.  
15. public static void main(String args[]){
16.  
17. Outer.inner in= new Outer.innner();
18.  
19. in.print();
20. } 
21.  
22. }

Output:

1. static inner class method called

Static inner class accessing outer class static variable:

1. package instanceofjavaTutorial;
2.  
3. public class Outer{ 
4.  static int a=10;
5.   static class inner{
6.  
7. public void print(){
8.  
9. System.out.println(a);
10.  
11. }
12.  
13. }
14.  
15. public static void main(String args[]){
16.  
17. Outer.inner in= new Outer.innner();
18.  
19. in.print();
20. } 
21.  
22. }

Output:

1. 10

• In java there are two types of nested classes one is static and another one is non static nested classes.
• We saw static classes in java lets see what will be there in non static nested classes.

Non-static nested class(inner class)

1. Member inner class
2. Anonymous inner class
3. Local inner class

• A class is defined within a class and outside of methods of that class known as member inner class.
• Anonymous inner class is a inner class which does not have a name and whose instance is created at the time creating class itself.
• A class which is defined inside a method of another class known as local inner class

Click here for more information about inner classes