java 封装工具类

abstract class Animal
{
public abstract void eat();
public abstract void jiao();
}

//封装行为工具类——动物具有的一些行为
class DoAnimal
{
public void doSome(Animal a)
{
a.eat();
a.jiao();
}
}
class Cat extends Animal
{
public void eat()
{
System.out.println("吃鱼");
}
public void jiao()
{
System.out.println("喵喵");
}
public void catchMouse()
{
System.out.println("捉老鼠");//特有方法
}
}

class Dog extends Animal
{
public void eat()
{
System.out.println("吃骨头");
}
public void jiao()
{
System.out.println("汪汪");
}
public void kanJia()
{
System.out.println("看家");//特有方法
}
}

class DuoTaiDemo1
{
public static void main(String args[])
{
DoAnimal da=new DoAnimal();
Cat c=new Cat();
da.doSome(c);
c.catchMouse();
da.doSome(new Dog());
}
}