Class B extends Class A but class A has a property of class B

Question

So I know this is confusing but why does this work? If I have

public class A implements Parcelable{
  private B propB;
}

public class B extends A implements Parcelable{
  private int stuff;
}

so if I ever created a

A objectA = new A(); 

wouldn't there be an infinite loop of this: objectA.propB.propB.propB?

the main issue is that I want to pass an instance of class B in android as a bundle, but this is not working, no error, just data doesn't get passed through. All the properties and data gets passed through except for that one property that seems to be a circular dependency..

is there a reason why this is good practice? or is it just not a good idea?

Answer 1

there is no error occurs in any case, because the B object only a private field of A, and is not initialization. but, if you create a new B instance, you only create a new object A().

if you want to use
objectA.propB.propB.propB.......
you can get the NullPointException.

Answer 2

The reason why data wasn't being passed through is because of parcels. I wasn't calling super(in) on the sub class B. so although there was no error there wasn't any data passing through either.