模拟实现十字路口的交通灯管理系统逻辑,具体需求如下:
Ø 异步随机生成按照各个路线行驶的车辆。
例如:
由南向而来去往北向的车辆 ---- 直行车辆
由西向而来去往南向的车辆 ---- 右转车辆
由东向而来去往南向的车辆 ---- 左转车辆
。。。
Ø 信号灯忽略黄灯,只考虑红灯和绿灯。
Ø 应考虑左转车辆控制信号灯,右转车辆不受信号灯控制。
Ø 具体信号灯控制逻辑与现实生活中普通交通灯控制逻辑相同,不考虑特殊情况下的控制逻辑。
注:南北向车辆与东西向车辆交替放行,同方向等待车辆应先放行直行车辆而后放行左转车辆。
Ø 每辆车通过路口时间为1秒(提示:可通过线程Sleep的方式模拟)。
Ø 随机生成车辆时间间隔以及红绿灯交换时间间隔自定,可以设置。
Ø 不要求实现GUI,只考虑系统逻辑实现,可通过Log方式展现程序运行结果。
面向对象的分析和设计:
List<String> vechicles = new ArrayList<String>();
private String name = null;
public Road(String name){
this.name = name;
ExecutorService executorService = Executors.newSingleThreadExecutor();
executorService.execute(new Runnable(){
@Override
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);
}
}
});
ScheduledExecutorService scheduled = Executors.newScheduledThreadPool(1);
scheduled.scheduleAtFixedRate(
new Runnable(){
@Override
public void run() {
if(vechicles.size() > 0){
boolean lighted = Lamp.valueOf(Road.this.name).isLighted();
if(lighted){
System.out.println(vechicles.remove(0) + " is tranversing !");
}
}
}
},
1,
1,
TimeUnit.SECONDS);
}
}
public enum Lamp {
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);
private Lamp(String opposite,String next,boolean lighted){
this.opposite = opposite;
this.next = next;
this.lighted = lighted;
}
private boolean lighted;
private String opposite;
private String next;
public boolean isLighted(){
return lighted;
}
public void light(){
this.lighted = true;
if(opposite != null){
Lamp.valueOf(opposite).light();
}
System.out.println(name()+" lamp is green , 下面总共有六个方向能看到汽车穿过!");
}
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;
}
}
lampContriller 类:public class LampController {
private Lamp currentLamp;
public LampController() {
currentLamp = Lamp.S2E;
currentLamp.light();
ScheduledExecutorService schedu=Executors.newScheduledThreadPool(1);
schedu.scheduleAtFixedRate(
new Runnable(){
@Override
public void run() {
System.out.println("开始了");
currentLamp =currentLamp.blackOut();
}
},
10,
10,
TimeUnit.SECONDS);
}
}
MainClass 类:
public class MainClass {
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();
}
}