用观察者模式和非观察者模式设计一个交通信号灯调度系统

package com.test03; import java.util.LinkedList; import java.util.Observable; import java.util.Observer; import java.util.Queue; import java.util.Random; import java.util.Timer; import java.util.TimerTask; import java.util.concurrent.Executors; import java.util.concurrent.ScheduledExecutorService; import java.util.concurrent.TimeUnit; public class Road implements Observer { private String name;// 路名 private Queue<String> vehicles = new LinkedList<String>();// 车辆集合 private Timer timer2 = null; public Road(Lamp lamp) { lamp.addObserver(this);// 注册一个观察者 this.name = lamp.getName(); ScheduledExecutorService timer = Executors.newScheduledThreadPool(1); timer.schedule(new Runnable() { @Override public void run() { for (int i = 0; i < 1000; i++) { try { Thread.sleep((new Random().nextInt(10) + 1) * 1000); } catch (InterruptedException e) { e.printStackTrace(); } vehicles.offer("" + i); } } }, 0, TimeUnit.SECONDS); } @Override public void update(Observable o, Object arg) { if (arg == Boolean.TRUE) {// 绿灯亮了 System.out.println(name + "方向已经开始放行车辆通过!"); timer2 = new Timer(); timer2.schedule(new TimerTask() { @Override public void run() { if (vehicles.size() > 0) { String current = vehicles.poll(); System.out.println(Road.this.name + "路的当前第" + current + "号正在通过路口!"); } } }, 1000, 1000); } else {// 红灯亮了 timer2.cancel(); System.out.println(name + "方向已停止车辆通行!"); } } }