手写简单的【观察者模式】

1、创建回调接口

public interface IObserver {void onResult(String result);
}

2、创建调度中心

public class Observer {private Observer() {}private static class SingleTon {static Observer INSTANCE = new Observer();}public static Observer getInstance() {return SingleTon.INSTANCE;}private Map<String, IObserver> map = new ConcurrentHashMap<>();public void subScript(String key, IObserver callback) {map.put(key, callback);}public void notify(String key, String str) {if (map.containsKey(key)) {IObserver callback = map.get(key);callback.onResult(str);}}
}

3、发送通知

Observer.getInstance().notify("notify","我是Two");

4、注册并响应通知

Observer.getInstance().subScript("notify", new IObserver() {@Overridepublic void onResult(String result) {}});