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?
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)