1、定义
观察者模式：对象间一对多依赖关系，一个对象改变，依赖于它对象得到通知并更新
写法
/**
* 被观察者
*/
public interface IObservable {
//注册
void register(IObserver observer);
//通知
void notify(String msg);
}
/**
* 观察者
*/
public interface IObserver {
//更新
void update(String msg);
}
public class Tv implements IObservable {
List<IObserver> list = new ArrayList<>();
@Override
public void register(IObserver observer) {
list.add( observer );
}
@Override
public void notify(String msg) {
for (IObserver observer : list) {
observer.update( msg );
}
}
}
/**
* 观察者
*/
public class User implements IObserver {
private String name;
public User(String name) {
this.name = name;
}
@Override
public void update(String msg) {
System.out.println( name + "," + msg + "更新了！" );
}
}
public class TestMain {
public static void main(String[] args){
User user1 = new User( "小米" );
User user2 = new User( "小名" );
User user3 = new User( "小明" );
Tv tv = new Tv();
tv.register( user1 );
tv.register( user2 );
tv.register( user3 );
tv.notify( "甄嬛来了" );
}
}
