Initialize-on-demand Holder Class

public class  Singleton {    
   
         private static class  SingletonHandler{    
   
                      static final  Singleton  singleton =new  Singleton();     
   
         }    
   
         private  Singleton (){}    
   
         public static  Singleton getInstance(){    
   
                    return SingletonHandler.singleton;    
   
         }    
   
}