inner class within a method as abstract???

[Somasekar Reddy]

Hi,
What is the use of declaring the inner class within a method as abstract???
Thanks,
Reddy.

[Barry Gaunt]

For ensuring that a subclass provides an implementation of the method:

public class BS
{
   private int x;
 
    public void sampleMethod()
    {
        abstract class A{
            abstract void foo();
        };
        
        A a1 = new A() {
            void foo() {
                System.out.println("AAAA");
            }
        };
        a1.foo();
        
        A a2 = new A() {
            void foo() {
                System.out.println("BBBB");
            }
        };
        a2.foo();
    }
}
    

[Somasekar Reddy]

Thanks.