黑马程序员：交通灯案例

---------------------- android培训、java培训、期待与您交流！ ----------------------

   设计需求；模拟现实十字路口交通灯管理逻辑，具体需求如下：

a、 异步随机生成按照各个路线行驶的车辆。

b、 信号灯忽略黄灯，仅考虑绿红；

c、 右转灯不受信号灯控制；

d、 南北向车辆和东西向车辆交替放行，同方向等待车辆应先放行直行车辆再放行左传车辆；

e、 每辆车通行时间为1秒（通过线程sleep方式模拟）；

f、 随机生成车辆和时间间隔以及红绿灯交换时间间隔自定，可以设置；

g、 不要求实现GUI，仅考虑逻辑实现，可以通过log方式展现效果。

通过分析先确定案例中所涉及的对象：道路，交通灯，当然还有交通灯控制器。

道路所要实现的代码有：

package com.isoftware;

import java.util.ArrayList;

import java.util.List;

import java.util.Random;

import java.util.concurrent.Executor;

import java.util.concurrent.ExecutorService;

import java.util.concurrent.Executors;

import java.util.concurrent.ScheduledExecutorService;

import java.util.concurrent.TimeUnit;

import javax.jws.soap.SOAPBinding.Use;

public class Road {
   private  List<String> vechicles=new ArrayList<String>();
   public String name=null;
   public Road(String name){
 this.name=name;
Executor pool= Executors.newSingleThreadExecutor();
pool.execute(new Runnable() {
@Override
public void run() {
// TODO Auto-generated method stub
for(int i=1;i<1000;i++)//车的辆数
{
try {
Thread.sleep((new Random().nextInt(10)+1)*1000);
} catch (InterruptedException e) {
// TODO Auto-generated catch block
e.printStackTrace();
}
vechicles.add(Road.this.name+"_"+i);
}
}
});
//定时器
ScheduledExecutorService timer=Executors.newScheduledThreadPool(1);
timer.scheduleAtFixedRate(
new Runnable() {
public void run() {
// TODO Auto-generated method stub
if(vechicles.size()>0){
boolean lighted=Lamp.valueOf(Road.this.name).islighted();
  if(lighted){
  System.out.println(vechicles.remove(0)+"is travelling");
        }

            }
  }
}, 1, 1,TimeUnit.SECONDS);
}
}

灯控制器：

   package com.isoftware;
import java.util.concurrent.Executor;
import java.util.concurrent.Executors;
import java.util.concurrent.ScheduledExecutorService;
import java.util.concurrent.TimeUnit;
import org.omg.CORBA.Current;
public class LampControllor {
      private Lamp currentLamp;
public LampControllor(){
currentLamp = Lamp.S2N;
currentLamp.light();
ScheduledExecutorService timer=Executors.newScheduledThreadPool(1);
timer.scheduleAtFixedRate(
new Runnable() {

@Override
public void run() {
// TODO Auto-generated method stub
System.out.println("我来了");
currentLamp=currentLamp.blacklight();
}
},
10,
10,
   TimeUnit.SECONDS);

}
}

交通灯：使用枚举来列出它的变化。

package com.isoftware;
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),
N2W(null,null,true),S2E(null,null,true),E2N(null,null,true),W2S(null,null,true);
private boolean lighted;
private String opposite;
private String next;
private Lamp(){}
private Lamp(String oppisite,String next,boolean lighted){
this.opposite=oppisite;
this.next=next;
this.lighted=lighted;
}
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,下面总共应该有六个方向的车可以看到");
}
public Lamp blacklight(){
this.lighted=false;
if(opposite!=null){
Lamp.valueOf(opposite).blacklight();
}
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;
}
}

这个是主程序要实现的代码：

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

通过此案例的学习，我深刻了解了面向对象的重要性，谁是动作的具体实施者，并且该数据属于该对象的属性，方法就属于谁，对象中有数据，内部就应该有其提供出来的方法。

---------------------- android培训、java培训、期待与您交流！ ----------------------