When polimorphism is not what you desire

Question

Suppose you have the following program:
class A
     public void methodA()
          System.out.println("A.methodA()");
     public void callMethodA()
          System.out.println("A.callMethodA()");
          methodA();
class B extends A
     public void methodA()
          System.out.println("B.methodA()");
     public void callMethodA()
          System.out.println("B.callMethodA()");
          super.callMethodA();
public class Test
     public static void Go()
          B b = new B();
          b.callMethodA();
}What is the output after you run Test.Go()? Yes, you guessed it right (didn't you?):
B.callMethodA()
A.callMethodA()
B.methodA()
This is a consequence of all methods being polimorphic ("virtual" in C++ jargon) by default in Java. I ran into a situation today in which I needed that the output was
B.callMethodA()
A.callMethodA()
B.methodA()
This is, that invoking super.callMethodA() from an instance of B (or from any descendant of A) would call A's methodA(), not B's methodA(). Sadly, there doesn't seem to be any way to prevent that a method behaves polimorphically. My solution was to rename A.methodA() as A.aMethodA() and qualify it as "final" and then make A.callMethodA() calls A.aMethodA().
Thoughts?

Answer 1

McCormick wrote:
Well, B's methodA() is a useful method so I can't remove it. Indeed, the solution of renaming A.methodA() could have been instead "rename B.methodA()". My point was that I ran into a situation where I didn't want/expect a polimorphic behavior but that's what I got. Since Java doesn't provide any other way to prevent pholimorphism (compared to C++/C# where you may not qualify a method as "virtual"), you have to use "final" to avoid it.
Thoughts?Yes, don't think like a C++ programmer.
class A {
     private void methodAHelper()     {
          System.out.println("A.methodA()");
     public void methodA()     {
          methodAHelper();
     public void callMethodA() {
          System.out.println("A.callMethodA()");
          methodAHelper();
class B extends A {
     public void methodA() {
          System.out.println("B.methodA()");
     public void callMethodA() {
          System.out.println("B.callMethodA()");
          super.callMethodA();
public class Test {
     public static void Go() {
          B b = new B();
          b.callMethodA();
}and no final keywords.
Winston