How to deal with Java Polymorphism in Service Oriented Architecture

Question

What is the path of least evil when dealing with polymorphism and inheritance of entity types in a service-oriented architecture?

A principle of SOA (as I understand

Answer 1

Having thought about this a bit more I've thought on an alternative approach that makes for a simpler design.

abstract class Animal {
}

class Cat extends Animal {
    public String meow() {
        return "Meow";
    }
}

class Dog extends Animal {
    public String  bark() {
        return "Bark";
    }
}

class AnimalService { 
    public String getSound(Animal animal) {
        try {
            Method method = this.getClass().getMethod("getSound", animal.getClass());
            return (String) method.invoke(this, animal);
        } catch (Exception e) {
            throw new RuntimeException(e);
        }
    }
    public String getSound(Cat cat) {
        return cat.meow();
    }
    public String getSound(Dog dog) {
        return dog.bark();
    }
}

public static void main(String[] args) {
    AnimalService animalService = new AnimalService();
    List animals = new ArrayList();
    animals.add(new Cat());
    animals.add(new Dog());

    for (Animal animal : animals) {
        String sound = animalService.getSound(animal);
        System.out.println(sound);
    }
}