public class AbstDemo {

public static void main(String[] args) {

    Person p1 = new Chinese();

    Person p2 = new American();

    p1.say();

    p2.say();

    }

}

abstract class Person{

abstract void say();

}

class Chinese extends Person{

void say() {

    System.out.println("中国人说汉语");

    }

}

class American extends Person{

void say() {

    System.out.println("美国人说英语");

    }

}