Singleton.java

package NestedClass;

class CoffeeMachine
{
    private float coffeeQty;
    private float milkQty;
    private float waterQty;
    private float sugarQty;

    static private CoffeeMachine my = null;

    private CoffeeMachine()
    {
        coffeeQty=1;
        milkQty=1;
        waterQty=1;
        sugarQty=1;
    }

    public void fillWater(float qty)
    {
        waterQty=qty;
    }
    public void fillSugar(float qty)
    {
        sugarQty=qty;
    }
    public float getCoffee()
    {
        float amount;
        amount = waterQty + milkQty;
        return amount;
    }

    static CoffeeMachine getInstance()
    {
        if(my==null)
            my=new CoffeeMachine();
        return my;
    }


}
public class Singleton
{
    public static void main(String[] args)
    {
        CoffeeMachine m1=CoffeeMachine.getInstance();
        CoffeeMachine m2=CoffeeMachine.getInstance();
        CoffeeMachine m3=CoffeeMachine.getInstance();

        System.out.println(m1+" "+m2+" "+m3);
        if(m1==m2 && m1==m3)
            System.out.println("Same");

    }
}