How to count the number of instances of a particular class in inheritance tree, created explicitly?

Question

class A { 
    static int i;
    {
        System.out.println("A init block"+ ++i);
    }

}
class B extends A {
    static int j;
    {
        System.out.println("B init block"+ ++j);
    }
}
class C extends B {
    static int k;
    {
        System.out.println("C init block"+ ++k);
    }
        public static void main(String abc[])
        {
          C c =new C();
        }
}

In the code above, we can easily count the number of objects created for each class. But if i want to check the number of object created explicitly , i mean if I create C's object using new C(), or B's object using new B(), then it should give the count accordingly

Take for example,

C c2=new C();
B b2=new B();

So it should give the output of B's count as 1 and not 2.

Solution

public class Foo {
    private static int fooCount = 0;

    public Foo() {
        if (this.getClass() == Foo.class) {
            fooCount++;
        }
    }

    public static int getFooCount() {
        return fooCount;
    }
}

Comments

[Rajdeep Siddhapura]

what is the need of checking this.getClass() == Foo.class ?

[JB Nizet]

If you don't fooCount will be incremented when a subclass of Foo is instantiated, since the subclass constructor always calls the superclass constructor.

[weno]

I believe this produces negative values for Test Count if number of NewTest instances is larger than number of Test instances.