继承和多态

package h;interface Person{    //定义接口Person    public abstract void Identity();   //定义方法Identity()}class Student implements Person{    public void Identity() {        System.out.println("人员身份：学生");   //定义类Student实现接口Person,并重写方法Identity()    }}class Teacher implements Person{    public void Identity() {        System.out.println("人员身份：教师");   //定义类Teacher实现接口Person,并重写方法Identity()    }}class PersonMessage{    public void showMessage(Person person) {  //接口Person作为方法的参数类型        person.Identity();   //接口Person作为方法showMessage（）的参数类型    }}public class wfh {    public static void main(String[] args) {        // TODO Auto-generated method stub        Student student=new Student();        Teacher teacher=new Teacher();    //创建对象        PersonMessage teacherMs=new PersonMessage();        student.Identity();        teacherMs.showMessage(teacher);   //将表示接口的实参teacher传给方法showMessage（）    }}

运行结果: