java创建定时任务

三种定时任务

package com.ytzn.task;

import java.util.Calendar;
import java.util.Date;
import java.util.Timer;
import java.util.TimerTask;

public class TaskTest {

    public static void main(String[] args) {
        timer3();
    }

    public static void timer1(){
        Timer timer = new Timer();
        timer.schedule(new TimerTask() {
            @Override
            public void run() {
                System.out.println("延时两秒定时任务开启");
            }
        },2000);//两千毫秒
    }

    public static void timer2(){
        Timer timer = new Timer();
        timer.schedule(new TimerTask() {
            @Override
            public void run() {
                System.out.println("adf");
            }
        },2000,4000);//延时两千毫秒，隔四千毫秒执行一次
    }

    public static void timer3() {
        Calendar calendar = Calendar.getInstance();
        calendar.set(Calendar.HOUR_OF_DAY, 20);//固定每天几点
        calendar.set(Calendar.MINUTE, 0);//该时间点的分钟
        calendar.set(Calendar.SECOND, 0);//该时间点该分钟多少秒
        Date time = calendar.getTime();
        Timer timer = new Timer();
        timer.scheduleAtFixedRate(new TimerTask() {
            public void run() {
                System.out.println("每天开启的定时任务");
            }
        }, time, 1000 * 60 * 60 * 24);// 这里设定将延时每天固定执行
    }
}