ScheduledExecutorService周期性的定时任务

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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demo

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();
}
}
}
}}