Anonymous concrete factory

We continue the previous code by adding a BikeFactory from where customers can select a small bike or a large bike. We can do this without creating a separate class file; we can simply create an anonymous class that extends the VehicleFactory directly in the client code:

VehicleFactory bikeFactory = new VehicleFactory() 
{
  @Override
  protected Vehicle createVehicle(String size) 
  {
    if (size.equals("small"))
    return new MountainBike();
    else if (size.equals("large"))
    return new CityBike();
    return null; 
  }
};
bikeFactory.orderVehicle("large", "blue");