不定长函参的Java观察者模式更新数据传递

 

import java.util.LinkedList; /** * 抽象被观察者。 * * @param <T> */ public abstract class Subject<T> { private LinkedList<Observer> observers; public Subject() { observers = new LinkedList<>(); } public Subject getSubject() { return this; } public void registerObserver(Observer observer) { observers.add(observer); } public void removeObserver(Observer observer) { observers.remove(observer); } public void notifyObserver(T... t) { for (Observer observer : observers) { observer.update(getSubject(), t); } } }

 

/** * 抽象观察者。 * @param <T> */ public interface Observer<T> { void update(Subject subject, T... t); }

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public class State extends Subject { @Override public Subject getSubject() { return this; } }

 

public class ObserverImpl implements Observer<Object> { @Override public void update(Subject subject, Object... objects) { StringBuffer sb = new StringBuffer(); for (Object o : objects) { sb.append(o.toString() + ","); } System.out.println("观察到更新:" + sb.toString()); } }

 

测试：

Subject subject = new State(); Observer observer = new ObserverImpl(); subject.registerObserver(observer); new Thread(new Runnable() { @Override public void run() { int i = 0; while (true) { try { TimeUnit.SECONDS.sleep(1); subject.notifyObserver((i++)+"",(i++)+""); } catch (Exception e) { e.printStackTrace(); } } } }).start();

 

输出：

观察到更新:0,1, 观察到更新:2,3, 观察到更新:4,5, 观察到更新:6,7, 观察到更新:8,9, 观察到更新:10,11,