Thinking in Java学习笔记ScheduledThreadPoolExecutor

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本文介绍了一个基于ScheduledThreadPoolExecutor的温室自动化控制系统实现。系统定时执行开关灯、调节温控、收集环境数据等功能，通过不同任务间的协调运行，实现了温室环境的智能化管理。

温室的开灯、关灯、开水、关水、白天热电、夜晚热电、收集数据（时间温度湿度）

ScheduledThreadPoolExecutor的schedule(event, delay, TimeUnit.MILLISECONDS)方法,在delay参数指定的时间后，只执行一次

ScheduledThreadPoolExecutor的.scheduleAtFixedRate(event, initialDelay, period, TimeUnit.MILLISECONDS)方法，在初始时间执行一次，且按照period指定的时间间隔周期的执行，相同时间的任务按照FIFO的顺序被调度

package com.test.concurrent;

import java.util.ArrayList;
import java.util.Calendar;
import java.util.Collections;
import java.util.List;
import java.util.Random;
import java.util.concurrent.ScheduledThreadPoolExecutor;
import java.util.concurrent.TimeUnit;

public class GreenHouseScheduler {

	public static void main(String[] args) {
		// TODO Auto-generated method stub
		GreenHouseScheduler gh=new GreenHouseScheduler();
		gh.schedule(gh.new Terminate(),5000);
		gh.repeat(gh.new Bell(), 0, 1000);
		gh.repeat(gh.new ThermostatNight(),0,2000);
		gh.repeat(gh.new LightOn(), 0, 200);
		gh.repeat(gh.new LightOff(),0,400);
		gh.repeat(gh.new WaterOn(), 0, 600);
		gh.repeat(gh.new WaterOff(),0,800);
		gh.repeat(gh.new ThermostatDay(),0,1400);
		gh.repeat(gh.new CollectData(), 500, 500);
	}
	private volatile boolean light=false;
	private volatile boolean water=false;
	private String thermostat="Day";
	public synchronized String getThermostat(){
		return thermostat;
	}
	public synchronized void setThermostat(String value){
		thermostat=value;
	}
	<span style="color:#ff0000;">ScheduledThreadPoolExecutor scheduler=new ScheduledThreadPoolExecutor(10);
	public void schedule(Runnable event, long delay){
		scheduler.schedule(event, delay, TimeUnit.MILLISECONDS);
	}
	public void repeat(Runnable event,long initialDelay,long period){
		scheduler.scheduleAtFixedRate(event, initialDelay, period, TimeUnit.MILLISECONDS);
	}</span>
	class LightOn implements Runnable{
		@Override
		public void run(){
			//put hardware control code here to physically turn on the ligth
			System.out.println("Turn on the lights!");
			light=true;
		}
	}
	class LightOff implements Runnable{
		@Override 
		public void run(){
			System.out.println("Turn lights off!!");
			light=false;
		}
	}
	class WaterOn implements Runnable{
		@Override
		public void run(){
			System.out.println("Turning GreenHouse water on");
			water=true;
		}
	}
	class WaterOff implements Runnable{
		@Override
		public void run(){
			System.out.println("Turning GreenHouse water off");
			water=false;
		}
	}
	class ThermostatNight implements Runnable{
		@Override
		public void run(){
			System.out.println("Set thermostat night!!");
			setThermostat("Night");
		}
	}
	class ThermostatDay implements Runnable{
		@Override
		public void run(){
			System.out.println("Set thermostat day!!");
			setThermostat("Day");
		}
	}
	class Bell implements Runnable{
		@Override
		public void run(){
			System.out.println("--------belling------------");
		}
	}
	class Terminate implements Runnable{
		@Override
		public void run(){
			System.out.println("***Terminating****");
			scheduler.shutdownNow();
			new Thread(){
				public void run(){
					for(DataPoint d:data){
						System.out.println(d);
					}
				}
			}.start();
		}
	}
	static class DataPoint{
		final Calendar time;
		final float temperature;
		final float humidity;
		public DataPoint(Calendar d,float temp, float hum){
			time=d;
			temperature=temp;
			humidity=hum;
		}
		public String toString(){
			return time.getTime()+" temperature:"+temperature+"    humidity:"+humidity;
		}
	}
	private Calendar lastTime=Calendar.getInstance();
	{
		lastTime.set(Calendar.MINUTE,30);
		lastTime.set(Calendar.SECOND, 00);
	}
	private float lastTemp=65.0f;
	private int tempDirection=+1;
	private float lastHumidity=50.0f;
	private int humidityDirection=+1;
	private Random rand=new Random(47);
	List<DataPoint> data=Collections.synchronizedList(new ArrayList<DataPoint>());
	
	class CollectData implements Runnable{
		@Override
		public void run(){
			System.out.println("Collecting Data::::::::");
			synchronized(GreenHouseScheduler.this){
				lastTime.set(Calendar.MINUTE, lastTime.get(Calendar.MINUTE)+30);
				if(rand.nextInt(5)==4)
					tempDirection=-tempDirection;
					lastTemp=lastTemp+tempDirection*(rand.nextFloat()+1.0f);
					
					if(rand.nextInt(5)==4)
						humidityDirection=-humidityDirection;
					lastHumidity=lastHumidity+humidityDirection*rand.nextFloat();
					
					data.add(new DataPoint((Calendar)lastTime.clone(),lastTemp,lastHumidity));
			}
		}
	}
}

执行结果如下：

--------belling------------ //第0秒开始，按照顺序首次执行了初始执行时间为0的所有任务
Set thermostat night!!
Turn on the lights!
Turn lights off!!
Turning GreenHouse water on
Turning GreenHouse water off
Set thermostat day!!
Turn on the lights!
Turn on the lights!
Turn lights off!!
Collecting Data::::::::
Turn on the lights!
Turning GreenHouse water on
Turn on the lights!
Turn lights off!!
Turning GreenHouse water off
--------belling------------
Turn on the lights!
Collecting Data::::::::
Turn on the lights!
Turn lights off!!
Turning GreenHouse water on
Turn on the lights!
Set thermostat day!!
Collecting Data::::::::
Turn on the lights!
Turn lights off!!
Turning GreenHouse water off
Turn on the lights!
Turning GreenHouse water on
--------belling------------
Set thermostat night!!
Turn on the lights!
Turn lights off!!
Collecting Data::::::::
Turn on the lights!
Turn on the lights!
Turn lights off!!
Turning GreenHouse water on
Turning GreenHouse water off
Collecting Data::::::::
Turn on the lights!
Turn on the lights!
Turn lights off!!
Set thermostat day!!
--------belling------------
Turn on the lights!
Turning GreenHouse water on
Collecting Data::::::::
Turn on the lights!
Turn lights off!!
Turning GreenHouse water off
Turn on the lights!
Collecting Data::::::::
Turn on the lights!
Turn lights off!!
Turning GreenHouse water on
Turn on the lights!
--------belling------------
Set thermostat night!!
Turn on the lights!
Turn lights off!!
Turning GreenHouse water off
Collecting Data::::::::
Turn on the lights!
Turning GreenHouse water on
Set thermostat day!!
Turn on the lights!
Turn lights off!!
Collecting Data::::::::
Turn on the lights!
Turn on the lights!
Turn lights off!!
Turning GreenHouse water on
Turning GreenHouse water off
***Terminating****
Thu Feb 26 17:00:00 CST 2015 temperature:66.399826 humidity:50.053413
Thu Feb 26 17:30:00 CST 2015 temperature:67.97782 humidity:50.47043
Thu Feb 26 18:00:00 CST 2015 temperature:69.71517 humidity:51.421486
Thu Feb 26 18:30:00 CST 2015 temperature:70.82953 humidity:50.874798
Thu Feb 26 19:00:00 CST 2015 temperature:72.03096 humidity:50.321068
Thu Feb 26 19:30:00 CST 2015 temperature:73.18805 humidity:49.92445
Thu Feb 26 20:00:00 CST 2015 temperature:71.93828 humidity:49.810783
Thu Feb 26 20:30:00 CST 2015 temperature:70.13756 humidity:50.251114
Thu Feb 26 21:00:00 CST 2015 temperature:68.93982 humidity:50.995125