How to I test if a
is a subclass of b
?
Class<?> a = A.class;
Class<?> b = B.class;
How to I test if a
is a subclass of b
?
Class<?> a = A.class;
Class<?> b = B.class;
If you want to know whether or not a Class
extends another, use Class#isAssignableFrom(Class). For your example, it would be:
if(B.class.isAssignableFrom(A.class)) { ... }
If you're interested in whether or not an instance is of a particular type, use instanceof
:
A obj = new A();
if(obj instanceof B) { ... }
Note that these will return true
if the class/instance is a member of the type hierarchy and are not restrictive to direct superclass/subclass relationships. For example:
// if A.class extends B.class, and B.class extends C.class
C.class.isAssignableFrom(A.class); // evaluates to true
// ...and...
new A() instanceof C; // evaluates to true
If you want to check for direct superclass/subclass relationships, Tim has provided an answer as well.
You want to know if b
is assignable from a
:
b.isAssignableFrom(a);
Additionally, if you want to know that a
is a direct subclass of b
:
a.getSuperclass().equals(b);