抽象工厂模式（Abstract Factory）[6]

            private Herbivore herbivore;

            private Carnivore carnivore;

            public AnimalWorld(ContinentFactory factory){

                        carnivore=factory. CreateCarnivore();

                        herbivore=factory. CreateHerbivore();

            }

            //Mehtods

            public void RunFoodChain(){

                        carnivore.Eat(herbivore);

            }

            public static void  main(String[] args){

                        AnimalWorld world=new AnimalWorld(new AfricaFactory());

                        world.RunFoodChain();

                        world=new AnimalWorld(new AmericaFactory());