Java Singleton Design pattern

A class which must create only one object (ie. One instance) irrespective of any number of object creations based on that class.

Steps to develop single ton class:- 

1.Create a Private construcor, so that outside class can not access this constructor. And declare a private static reference of same class

2.Write a public Factory method which creates an object. Assign this object to private static Reference and return the object

Sample Code:-

public class SingleTonExample

{

private static SingleTonExample st=null;

private SingleTonExample()

{

System.out.println(“\nIn constructor”);

}

public static SingleTonExample getInstance()

{

if(st==null)

st=new SingleTonExample();

return st;

}

}

How to use the Singleton class created above is described in below class:

public class UsingSingletonClass{

             public void testMethod(){

               SingleTonExample st = SingleTonExample.hetInstance();

               //you can use the SingleTonExample object st for your requirements

}

}