java张孝祥（6） 交通灯管理系统

 

这个项目要是给我来写，我一定没有张老师写的好，之前没涉及过枚举类，不会使用，通过老师的讲解，以及分析思路，让我更加明白业务逻辑。

看来去黑马学习一定没有错，我一定要成为黑马的一员。

下面是老师的代码，我加以注释。

Lamp.java

package com.ici.interview.traffic;public enum Lamp {/* 创建12中路线的灯，以及设定他们相关联的上下灯，并设定灯的当前状态是否为绿灯*/S2N("N2S","S2W",false),S2W("N2E","E2W",false),E2W("W2E","E2S",false),E2S("W2N","S2N",false),N2S(null,null,false),N2E(null,null,false),W2E(null,null,false),W2N(null,null,false),S2E(null,null,true),E2N(null,null,true),N2W(null,null,true),W2S(null,null,true);/* 灯的构造方法，参数为 上一个灯，下一个灯，当前是否为绿*/private Lamp(String oppoite,String next,boolean lighted){this.opposite = oppoite;this.next = next;this.lighred = lighted;}private boolean lighred;private String opposite;private String next;/* 返回当前灯是否为绿*/public boolean isLighted(){return lighred;}//开灯public void light(){this.lighred = true;if(opposite!=null){Lamp.valueOf(opposite).light();}System.out.println(name() + " Lamp is green !");}//关灯public Lamp blackOut(){this.lighred = true;if(opposite!=null){Lamp.valueOf(opposite).blackOut();}//注意这里要设置为空不要赋值Lamp nextLamp = null;if(next!=null){System.out.println("绿灯从 " +name()+ " 切换为 " +next);nextLamp = Lamp.valueOf(opposite);Lamp.valueOf(opposite).light();}return nextLamp;}}

 

Road.java

package com.ici.interview.traffic;import java.util.ArrayList;import java.util.Random;import java.util.concurrent.ExecutorService;import java.util.concurrent.Executors;import java.util.concurrent.ScheduledExecutorService;import java.util.concurrent.TimeUnit;public class Road {private ArrayList<String> vechicles = new ArrayList<String>();private String name = null;public Road(String name){this.name = name;ExecutorService pool =Executors.newSingleThreadExecutor();//启动一个线程pool.execute(new Runnable() {public void run() {for (int i=0; i<1000; i++) {try {Thread.sleep((new Random().nextInt(5)+1) * 1000);} catch (InterruptedException e) {e.printStackTrace();}vechicles.add(Road.this.name+ "_" + i);}}});//定时器ScheduledExecutorService timer = Executors.newScheduledThreadPool(1);timer.scheduleAtFixedRate(new Runnable() {public void run() {if(vechicles.size()>0){boolean lighted = Lamp.valueOf(Road.this.name).isLighted();if(lighted){System.out.println(vechicles.remove(0)+ " is traversing !");}}}},1,1,TimeUnit.SECONDS);}}

 

Main.java

package com.ici.interview.traffic;public class Main {public static void main(String[] args) {String[] directions = new String[]{"S2N","S2W","E2W","E2S","N2S","N2E","W2E","W2N","S2E","E2N","N2W","W2S"};for (int i=0; i<directions.length; i++) {new Road(directions[i]);}new LampController();}}

LampController.java

package com.ici.interview.traffic;import java.util.concurrent.Executors;import java.util.concurrent.ScheduledExecutorService;import java.util.concurrent.TimeUnit;public class LampController {private Lamp currentLamp;//交通灯控制器，设置换灯时间。public LampController(){currentLamp = Lamp.S2N;currentLamp.light();ScheduledExecutorService timer = Executors.newScheduledThreadPool(1);timer.scheduleAtFixedRate(new Runnable() {public void run() {currentLamp = currentLamp.blackOut();}},10,10,TimeUnit.SECONDS);}}