///Animal类

package d922A;

public class Animal {

private String kind;

public String getKind() {    System.out.println(kind);    return kind;        }public void setKind(String kind) {    this.kind = kind;}public void eat(){    System.out.println("I can eat.");}public void sleep(){    System.out.println("I can sleep.");}

}

//Fish 子类

package d922A;

public class Fish extends Animal {

Fish()

{

setKind("鱼");

}

public void eat()

{

System.out.println("吃水草。");

}

public void sleep()

{

System.out.println("睁着眼睡觉。");

}

}

//Dog类

package d922A;

public class Dog extends Animal {

Dog()

{

setKind("狗");

}

public void eat()

{

System.out.println("吃肉。");

}

public void sleep()

{

System.out.println("闭着眼睡觉。");

}

}

//主类

package d922A;

public class E {

public static void main(String[] args) {    Animal a=new Animal();    a.eat();    a.sleep();    Fish f=new Fish();    f.getKind();    f.eat();    f.sleep();    Dog d=new Dog();    d.getKind();    d.eat();    d.sleep();}

}

//运行结果

I can eat.

I can sleep.

鱼

吃水草。

睁着眼睡觉。

狗

吃肉。

闭着眼睡觉。