How to check if a subclass is an instance of a class at runtime? [duplicate]

Question

In an android app test suite I have a class like this where B is a view:

public class A extends B { ... etc... } 

now I have a list of view objects which may contain A objects but in this case I only care if they're subclasses or "instances of" B. I'd like to do something like:

ArrayList<View> viewList = getViews(); Iterator<View> iterator = viewList.iterator(); while (iterator.hasNext() && viewList != null) {     View view = iterator.next();     if (view.getClass().isInstance(B.class)) {         // this is an instance of B     } } 

The problem is that when the if encounters an A object it doesn't evaluate to an "instance of B". Is there a way to do isSubclassOf or something?

Answer 1

You have to read the API carefully for this methods. Sometimes you can get confused very easily.

It is either:

if (B.class.isInstance(view)) 

API says: Determines if the specified Object (the parameter) is assignment-compatible with the object represented by this Class (The class object you are calling the method at)

or:

if (B.class.isAssignableFrom(view.getClass())) 

API says: Determines if the class or interface represented by this Class object is either the same as, or is a superclass or superinterface of, the class or interface represented by the specified Class parameter

or (without reflection and the recommended one):

if (view instanceof B)