多态练习（声音模拟器）

public class Application {

	public static void main(String[] args) {
		Simulator simulator = new Simulator();
		simulator.playSound(new Dog());
		simulator.playSound(new Cat());
	}

}

public abstract class Animal {
	abstract void cry();
	abstract String getAnimalName();
}

public class Cat extends Animal{
	void cry(){
		System.out.println("喵喵喵");
	}
    String getAnimalName(){
    	return "咪呜";
	}
}

public class Dog extends Animal{
	void cry(){
		System.out.println("汪汪汪");
	}
	 String getAnimalName(){
		return "旺财";
	}
}

public class Simulator {
void playSound(Animal animal){
		System.out.println(animal.getAnimalName()+"的叫声：");
		animal.cry();
	}
}