抽象类与接口作为形参

//抽象类作为形参
abstract class Stu
{
	public abstract void study();
}

class Person
{

	void method(Stu s)
	{
		s.study();
	}
}

class Man extends Stu
{
	public void study()
	{
		System.out.println("好好学习，天天向上");
	}
}

class Haha
{
	public static void main(String args[])
	{
		Person person = new Person();
		//多态，编译看Stu类里面有没有study这个成员方法，如果有就编译成功

		//然后执行是看右边的Man类，执行Man.study()
		Stu student = new Man();
		person.method(student);
	}
}

//接口作为形参
interface Person
{
	public abstract void study();
}

class Man
{
	void method(Person person)
	{
		person.study();
	}
}

class Stu implements Person
{
	public void study()
	{
		System.out.println("good good study,day day up");
	}
}

class Haha
{
	public static void main(String args[])
	{
		Person person = new Stu();
		new Man().method(person);
	}
}