Get all methods used in a Java class

Given a class, is it possible to list all the methods used by that particular class? Using getMethods() or getDeclaredMethods() does not work since I also want to get invoked methods beloning to imported classes.

public class A {
    public static void a(); 
}

public class B {
    public static void b(){
         A.a();
    }
}

If B uses A's method I'd also like to list it. How to do it?