public abstract class People {

?public abstract void yuyan();
}

public class China extends People {

?@Override
?public void yuyan() {
??// TODO Auto-generated method stub
??System.out.println("中國人說漢語");
?}
}

public class American extends People {

?@Override
?public void yuyan() {
??// TODO Auto-generated method stub
??System.out.println("美國人說英文");
?}?
}

public class InnerDeom {

?public static void main(String[] args) {
??// TODO Auto-generated method stub

???People p1 = new China();
???p1.yuyan();
???People p2 = new American();
???p2.yuyan();
?}
}

????????????????????????????????????????????????????????輸出：

????????????????????????????????????????????????????????????????????????中國人說漢語
????????????????????????????????????????????????????????????????????????美國人說英文