Question

I’m calling this linear class relationship, but correct me if I’m wrong. I’m looking to test whether or not the class of object A is an ancestor or descendant of object B‘s class.

For example, AbstractCollection is linearly related to both Object and ArrayList. However, ArrayList is not linearly related to Vector.

My first stab was:

// ...Assume objects A and B were declared...  Class<? extends Object> Aclass = A.getClass(); if (Aclass.isAssignableFrom(B.getClass()) || Aclass.isInstance(B)) {     // Their types are linearly related, at the least } 

Is this an appropriate check?

Answer 1

Your test works. I prefer the symmetric check:

if (a.getClass().isInstance(b) || b.getClass().isInstance(a)) {  }