Java接口

abstract class Animal
{  
    int legs;  
    public Animal(int legs){
             this.legs=legs;
    }
    public Animal(){}
    public abstract void eat();
    public void walk(){
        //System.out.println("动物用"+legs+"走路"); 
    }
    public void play(){
    }
}

class Spider extends Animal{
      
           public Spider(int legs){
               this.legs=legs;
           }
          public void  eat(){
             //System.out.println("动物eat!";   
    }
}


interface Pet{
    public String getName();
    public void setName(String name);
}


class Cat extends Animal implements Pet{
    String name;
    public Cat(){}
    
    public Cat(String name){    
        this.name=name;
     }

    @Override 
    public String getName(){
        return this.name;
    }
    @Override
    public void setName(String name) {        
        this.name=name;
    }

    public void eat(){    
        System.out.println(name+"喜欢Jerry！");   
    }
    public void play(){    
        System.out.println(name+"喜欢毛线球！");   
    }

    
}


class Fish extends Animal implements Pet{
    String name;
    public Fish(){}
    public Fish(String name){    
        this.name=name;
    }
    @Override 
    public void setName(String name){
        this.name=name;
    }
    @Override 
    public String getName(){
        return this.name;
    }
    public void eat(){    
        System.out.println(name+"喜欢浮游生物！");   
    }
    @Override
    public void play(){    
        System.out.println(name+"喜欢水泡泡！");   
    }
    public void walk(){    
        System.out.println(name+"走路不用脚");   
    }
}


public class AnimalsTest{  
    public static void main(String[] args){        
        Cat Tom=new Cat("Tom");    
        Tom.eat();    
        Tom.play();
        Tom.setName("Tom's son");
        Tom.play();
        Fish Nemo=new Fish("Nemo");
        Nemo.eat();
        Nemo.play();
        Nemo.walk();
    }