Java的观察者

时间:2022-04-26 18:14:35
class Teacher extends  Observable
{
public void startLesson()
{
System.out.println(String.format("老师说开始上课"));
super.setChanged();
super.notifyObservers();
}
} class Student implements Observer
{
private String name;
public Student(String name)
{
this.name=name;
}
@Override
public void update(Observable o, Object arg)
{
System.out.println(String.format("Name:%s起立",name));
}
public String getName()
{
return name;
}
}
public static void main(String[] args) {

        Teacher sir=new Teacher();
sir.addObserver(new Student("Grace") );
sir.addObserver(new Student("Aven") );
sir.startLesson();
}