Program to explain partial implementation of an interface in Java

//  Program to explain partial implementation of an interface.
interface AInterface
{
void showA();
void showB();
}
abstract  class  B  implements  AInterface 
{
public void showA()
{
 System.out.println("showA() of A interface.");
}
}
class Test extends B
{
public void showB()
{
 System.out.println("showB() of A interface.");
}
}
class InterfaceTest3
{
public static void main( String args[ ] )
{
 AInterface  a1 = new Test();
 a1.showA();
 a1.showB();
}
}

Output:
showA() of A interface.
showB() of A interface.