How do I determine if a class extends another class in Java?

Question

In Java how do I go about determining what classes a class extends?

public class A{ }  public class B extends A{ }  public class C extends A{ }  public class D{ }  public class E extends B{ }  public class doSomething{      public void myFunc(Class cls){          //need to check that cls is a class which extends A          //i.e. B, C and E but not A or D     } } 

would cls.getSuperClass() do what I need?

Answer 1

The getSuperClass() approach would fail for E since its immediate superclass is not A, but B. Rather use Class#isAssignableFrom().

public void myFunc(Class cls){      //need to check that cls is a class which extends A      //i.e. B, C and E but not A or D       if (cls != A.class && A.class.isAssignableFrom(cls)) {          // ...      } }