java交通灯标准管理系统源代码.doc

package com.isoftstone.interview.traffic;

import java.util.ArrayList;
import java.util.List;
import java.util.Random;
import java.util.concurrent.ExecutorService;
import java.util.concurrent.Executors;
import java.util.concurrent.ScheduledExecutorService;
import java.util.concurrent.TimeUnit;

/**
* 每个Road对象代表一条路线，总共有12条路线，即系统中总共要产生12个Road实例对象。
* 每条路线上随机增加新车辆，增加到一个集合中保留。
* 每条路线每隔一秒全部会检验控制本路线灯是否为绿，是则将本路线保留车集合中第一辆车移除，即表示车穿过了路口。
* @author 张孝祥 315.org
*
*/
public class Road {
private List<String> vechicles = new ArrayList<String>();

private String name =null;
public Road(String name){
this.name = name;

//模拟车辆不停随机上途经程
ExecutorService pool = Executors.newSingleThreadExecutor();
pool.execute(new Runnable(){
public void run(){
for(int i=1;i<1000;i++){
try {
Thread.sleep((new Random().nextInt(10) + 1) * 1000);
} catch (InterruptedException e) {
e.printStackTrace();
}
vechicles.add(Road.this.name + "_" + i);
}
}

});

//每隔一秒检验对应灯是否为绿，是则放行一辆车
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);

}
}

package com.isoftstone.interview.traffic;

public class MainClass {

/**
* @param args
*/
public static void main(String[] args) {

/*产生12个方向路线*/
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]);
}

/*产生整个交通灯系统*/
new LampController();
}

}

package com.isoftstone.interview.traffic;

import java.util.concurrent.Executors;
import java.util.concurrent.ScheduledExecutorService;
import java.util.concurrent.TimeUnit;

public class LampController {
private Lamp currentLamp;

public LampController(){
//刚开始让由南向北灯变绿;
currentLamp = Lamp.S2N;
currentLamp.light();

/*每隔10秒将目前绿灯变为红灯，并让下一个方向灯变绿*/
ScheduledExecutorService timer = Executors.newScheduledThreadPool(1);
timer.scheduleAtFixedRate(
new Runnable(){
public void run(){
System.out.println("来啊");
currentLamp = currentLamp.blackOut();
}
},
10,
10,
TimeUnit.SECONDS);
}
}

package com.isoftstone.interview.traffic;

/**
* 每个Lamp元素代表一个方向上灯，总共有12个方向，全部总共有12个Lamp元素。
* 有以下部分方向上灯,每两个形成一组，一组灯同时变绿或变红，所以，
* 程序代码只需要控制每组灯中一个灯即可：
* s2n,n2s
* s2w,n2e
* e2w,w2e
* e2s,w2n
* s2e,n2w
* e2n,w2s
* 上面最终两行灯是虚拟，因为从南向东和从西向北、和它们对应方向不受红绿灯控制，
* 所以，能够假想它们总是绿灯。
* @author 张孝祥 315.org
*
*/
/**/

public enum Lamp {
/*每个枚举元素各表示一个方向控制灯*/
S2N("N2S","S2W",false),S2W("N2E","E2W",false),E2W("W2E","E2S",false),E2S("W2N","S2N",false),
/*下面元素表示和上面元素相反方向灯，它们“相反方向灯”和“下一个灯”应忽略不计！*/
N2S(null,null,false),N2E(null,null,false),W2E(null,null,false),W2N(null,null,false),
/*由南向东和由西向北等右拐弯灯不受红绿灯控制，所以，能够假想它们总是绿灯*/
S2E(null,null,true),E2N(null,null,true),N2W(null,null,true),W2S(null,null,true);

private Lamp(String opposite,String next,boolean lighted){
this.opposite = opposite;
this.next = next;
this.lighted = lighted;
}

/*目前灯是否为绿*/
private boolean lighted;
/*和目前灯同时为绿对应方向*/
private String opposite;
/*目前灯变红时下一个变绿灯*/
private String next;
public boolean isLighted(){
return lighted;
}

/**
* 某个灯变绿时，它对应方向灯也要变绿
*/
public void light(){
this.lighted = true;
if(opposite != null){
Lamp.valueOf(opposite).light();
}
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！");

}

/**
* 某个灯变红时，对应方向灯也要变红，而且下一个方向灯要变绿
* @return 下一个要变绿灯
*/
public Lamp blackOut(){
this.lighted = false;
if(opposite != null){
Lamp.valueOf(opposite).blackOut();
}

Lamp nextLamp= null;
if(next != null){
nextLamp = Lamp.valueOf(next);
System.out.println("绿灯从" + name() + "-------->切换为" + next);
nextLamp.light();
}
return nextLamp;
}
}