利用观察者模式来获取线程中的数据或者回调函数

//抽象主题角色，watched：被观察
public interface Watched
{
public void addWatcher(Watcher watcher);

public void removeWatcher(Watcher watcher);

public void notifyWatchers(Watcher watcher,String str);

}

//抽象观察者角色
public interface Watcher
{
public void update(String str);

}

import java.util.ArrayList;
import java.util.Iterator;
import java.util.List;

/**观察者管理
* @author huangziwang
*
*/
public class ConcreteWatched implements Watched
{
// 存放观察者
private static List<Watcher> list = new ArrayList<Watcher>();

public void addWatcher(Watcher watcher)
{
list.add(watcher);
}

public void removeWatcher(Watcher watcher)
{
list.remove(watcher);
}

public void notifyWatchers(Watcher watcher1,String str)
{
// 自动调用实际上是主题进行调用的
Iterator<Watcher> e = list.iterator();
while (e.hasNext()) {
Watcher watcher = e.next();

//精确找出观察者返回函数并从队列中删除
if (watcher.equals(watcher1)) {
watcher.update(str);
e.remove();
System.out.println(list.size());
}
}
}

}

public class ConcreteWatcher implements Watcher
{

public void update(String str)
{
System.out.println(str);
}

}

public class TestThread extends Thread {
private Watcher watcher;
// 将被观察者对象传入线程，这里充分显示了面向对象开发的好处
public TestThread (Watcher watcher) {
this.watcher = watcher;
}
public void run() {
Watched concreteWatched = new ConcreteWatched();
concreteWatched.notifyWatchers(watcher, "我是:" + hashCode());
}

}

public class Test
{
public static void main(String[] args)
{
Watched girl = new ConcreteWatched();
// 将观察者加入队列中
Watcher watcher1 = new ConcreteWatcher();
girl.addWatcher(watcher1);
TestThread t = new TestThread(watcher1);
t.start();
}
}

我是:743319257
0