Java Singleton-Private Constructor

We can make constructor as private. So that We can not create an object outside of the class.

This property is useful to create singleton class in java.

Singleton pattern helps us to keep only one instance of a class at any time.

The purpose of singleton is to control object creation by keeping private constructor.

public class MySingleTon {

     

    private static MySingleTon myObj;

    /**

     * Create private constructor

     */

    private MySingleTon(){

         

    }

    /**

     * Create a static method to get instance.

     */

    public static MySingleTon getInstance(){

        if(myObj == null){

            myObj = new MySingleTon();

        }

        return myObj;

    }

     

    public void getSomeThing(){

        // do something here

        System.out.println("I am here....");

    }

     

    public static void main(String a[]){

        MySingleTon st = MySingleTon.getInstance();

        st.getSomeThing();

    }

}