An inner class cannot be overriden like a method : Nested Classes « Class Definition « Java Tutorial

1. Java Tutorial
2. Class Definition
3. Nested Classes

class A {
  private InnerA y;
  protected class InnerA {
    public InnerA() { System.out.println("A.InnerA()"); }
  }
  public A() {
    System.out.println("New A()");
    y = new InnerA();
  }
}

class B extends A {
  public class InnerB {
    public InnerB() { System.out.println("B.InnerB()"); }
  }
}

public class MainClass{
  public static void main(String[] args) {
    new B();
  }
}