使用ScheduledExecutorService周期性的定时任务

来源：互联网发布：管理顾客的软件编辑：程序博客网时间：2024/04/28 14:40

从j2se的api文档上查看ScheduledExecutorService的方法都是推迟一段时间然后相隔一段时间之后再去执行，没有想Timer定时器一样的可以在定点时间执行的api，如果也想像Timer那样定时执行就需要对ScheduledExecutorService的方法传入参数处理一下，下面是个人使用ScheduledExecutorService做的每天凌晨3点做的定时执行任务demon

贴代码：

package com.liu.test;

import java.text.ParseException;
import java.text.SimpleDateFormat;
import java.util.Date;
import java.util.LinkedList;
import java.util.List;
import java.util.concurrent.Executors;
import java.util.concurrent.ScheduledExecutorService;
import java.util.concurrent.ScheduledFuture;
import java.util.concurrent.TimeUnit;

public class ThreadTest {

   public static void main(String[] args) {
       //创建含有三个线程的计划线程池
       ScheduledExecutorService service = Executors.newScheduledThreadPool(3);
       //一天的毫秒数
       long oneDay = 24 * 60 * 60 * 1000;
       //计算初始延迟的毫秒数
       long initDelay = getTimeMillis("3:00:00") - System.currentTimeMillis();
       initDelay = initDelay > 0 ? initDelay : initDelay + oneDay;

       List<String> list1 = new LinkedList<String>();
       list1.add("第一个 :");

       List<String> list2 = new LinkedList<String>();
       list2.add("第二个 ");

       List<String> list3 = new LinkedList<String>();
       list3.add("第三个 ");

       //执行三个任务
       ScheduledFuture future = service.scheduleAtFixedRate(new RunnableTest(list1), initDelay, oneDay, TimeUnit.MILLISECONDS);
       service.scheduleAtFixedRate(new RunnableTest(list2), initDelay, oneDay, TimeUnit.MILLISECONDS);
       service.scheduleAtFixedRate(new RunnableTest(list3), initDelay, oneDay, TimeUnit.MILLISECONDS);

   }

   private static long getTimeMillis(String time) {
       // TODO Auto-generated method stub
       SimpleDateFormat dateFormat = new SimpleDateFormat("yyyy-MM-dd HH:mm:ss");
       SimpleDateFormat dayFormat = new SimpleDateFormat("yyyy-MM-dd");

       try {
           long fixedTime = dateFormat.parse(dayFormat.format(new Date())+" "+time).getTime();
           return fixedTime;
       } catch (ParseException e) {
           // TODO Auto-generated catch block
           e.printStackTrace();
       }
       return 0;
   }

}

package com.liu.test;

import java.util.List;

public class RunnableTest implements Runnable {

   private List<String> list;

   public RunnableTest() {
   }

   public RunnableTest(List<String> list){
       this.list = list;
   }

   @Override
   public void run() {
       // TODO Auto-generated method stub
       for(int i=0;i<10;i++){
           if(i%3 == 0){
               try {
                   Thread.sleep(3000);
                   System.out.println(list.get(0)+ "3 number +" + i);
               } catch (InterruptedException e) {
                   // TODO Auto-generated catch block
                   e.printStackTrace();
               }
           }
       }
   }

}

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