Android using Singleton

Java Singleton Class Example Using 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.

=====> the main class

/*

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 */

package designpattern;

/**

 *

 * @author jiteshupadhyay

 */

public class DesignPattern {

    /**

     * @param args the command line arguments

     */

    public static void main(String[] args) {

        // TODO code application logic here

        Singleton tmp = Singleton.getInstance();

        tmp.demoMethod();

        

    }

}

===>the singleton class

/*

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 * and open the template in the editor.

 */

package designpattern;

/**

 *

 * @author jiteshupadhyay

 */

public class Singleton {

    

private static Singleton singleton = new Singleton( );

   

   /* A private Constructor prevents any other 

    * class from instantiating.

    */

   private Singleton(){ }

   

   /* Static 'instance' method */

   public static Singleton getInstance( ) {

      return singleton;

   }

   /* Other methods protected by singleton-ness */

   protected static void demoMethod( ) {

      System.out.println("demoMethod for singleton"); 

   }

}