1 public class Road {
 2     private List<String> vechicles = new ArrayList<String>();
 3
 4     private String name =null;
 5     public Road(String name){
 6         this.name = name;
 7
 8         //模拟车辆不断随机上路的过程
 9         ExecutorService pool = Executors.newSingleThreadExecutor();
10         pool.execute(new Runnable(){
11             public void run(){
12                 for(int i=1;i<1000;i++){
13                     try {
14                         Thread.sleep((new Random().nextInt(10) + 1) * 1000);
15                     } catch (InterruptedException e) {
16                         e.printStackTrace();
17                     }
18                     vechicles.add(Road.this.name + "_" + i);
19                 }
20             }
21
22         });
23
25         ScheduledExecutorService timer =  Executors.newScheduledThreadPool(1);
26         timer.scheduleAtFixedRate(
27                 new Runnable(){
28                     public void run(){
29                         if(vechicles.size()>0){
30                             boolean lighted = Lamp.valueOf(Road.this.name).isLighted();
31                             if(lighted){
32                                 System.out.println(vechicles.remove(0) + " is traversing !");
33                             }
34                         }
35
36                     }
37                 },
38                 1,
39                 1,
40                 TimeUnit.SECONDS);
41
42     }
43 }

package traffic;public enum Lamp {S2N("N2S","S2W",false),S2W("N2E","E2N",false),E2W("W2E","E2S",false),E2S("W2N","W2S",false),N2S(null,null,false),N2E(null,null,false),W2E(null,null,false),W2N(null,null,false),S2E(null,null,false),E2N(null,null,false),N2W(null,null,false),W2S(null,null,false);private boolean lighted;//对应的灯private String opposite;//下一个灯private String next;private Lamp(String opposite,String next,boolean lighted){this.opposite =opposite;this.next=next;this.lighted=lighted;}private Lamp(){}public boolean isLighted(){return lighted;}public void light(){this.lighted=true;if(opposite!=null){Lamp.valueOf(opposite).lighted=true;System.out.println(name() + " lamp is green，下面总共应该有6个方向能看到汽车穿过！");}}public Lamp blackOut(){this.lighted =false;if(opposite!=null){Lamp.valueOf(opposite).lighted=false;}Lamp nextLight =Lamp.valueOf(next);System.out.println("绿灯从" + name() + "-------->切换为" + next);    if(next!=null)nextLight.lighted=true;return nextLight;}}

package traffic;import java.util.concurrent.Executors;
import java.util.concurrent.ScheduledExecutorService;
import java.util.concurrent.TimeUnit;public class LampController {private Lamp currentLamp;public LampController(){currentLamp =Lamp.S2N;currentLamp.light();ScheduledExecutorService timer = Executors.newScheduledThreadPool(1);timer.scheduleAtFixedRate(new Runnable(){public void run(){LampController.this.currentLamp =currentLamp.blackOut();}}, 10, 10, TimeUnit.SECONDS);}}

package traffic;public class MainClass {public static void main(String[] args){String[] directions ={"S2N","S2W","E2W","E2S","N2S","N2E","W2E","W2N","S2E","E2N","N2W","W2S"};for(String direction:directions){new Road(direction);}new LampController();}}