The best way to implement Factory without if, switch

Question

I was looking through many approaches to implement a Factory pattern in Java and still couldn\'t find a perfect one which doesn\'t suffer from both if/switch plus doesn\'t u

Answer 1

If you are using java 8, you can set up an enum like this:

enum AnimalFarm {
    Meow(Cat::new),
    Woof(Dog::new);

    public final Supplier factory;
    private AnimalFarm(Supplier factory) {
        this.factory = requireNonNull(factory);
    }
}

......

Animal dog = AnimalFarm.valueOf("Woof").factory.get();

You could even have the enum implement Supplier and then do AnimalFarm.valueOf("Meow").get();.