Java 抽象类

abstract class Animal {
  private String name;
  Animal(String name) {this.name = name;}
  /*
  public void enjoy(){
    System.out.println("叫声......");
  }
  */
  public abstract void enjoy();
}

abstract class Cat extends Animal {
  private String eyesColor;
  Cat(String n,String c) {super(n); eyesColor = c;}
  /*
  public void enjoy() {
    System.out.println("猫叫声......");
  }
  */
  //public abstract void enjoy();

}

class Dog extends Animal {
  private String furColor;
  Dog(String n,String c) {super(n); furColor = c;}

  public void enjoy() {
    System.out.println("狗叫声......");
  }
}

class Bird extends Animal {
     Bird() {
          super("bird");
     }
     public void enjoy() {
        System.out.println("鸟叫声......");
    }
}

class Lady {
    private String name;
    private Animal pet;
    Lady(String name,Animal pet) {
        this.name = name; this.pet = pet;
    }
    public void myPetEnjoy(){pet.enjoy();}
}

public class Test {
    public static void main(String args[]){
 // Cat c = new Cat("catname","blue");

        Dog d = new Dog("dogname","black");
        Bird b = new Bird();
        //Lady l1 = new Lady("l1",c);

        Lady l2 = new Lady("l2",d);
        Lady l3 = new Lady("l3",b);
       //l1.myPetEnjoy();

        l2.myPetEnjoy();
        l3.myPetEnjoy();
    }
}