java程序定时器

1.java定时器原生方法

实现每天早上8点执行任务的示例代码

import java.util.concurrent.ScheduledExecutorService;
import java.util.concurrent.ScheduledThreadPoolExecutor;
import java.util.concurrent.TimeUnit;

public class TimeTest{
    public static void main(String[] args) {
        ScheduledExecutorService timer = new ScheduledThreadPoolExecutor(1);
        MyTask task1 = new MyTask();
                // 获取当前时间
        Calendar now = Calendar.getInstance();
        // 设置每天早上8点执行
        Calendar scheduleTime = Calendar.getInstance();
        scheduleTime.set(Calendar.HOUR_OF_DAY, 8);
        scheduleTime.set(Calendar.MINUTE, 0);
        scheduleTime.set(Calendar.SECOND, 0);
        // 如果当前时间已经超过了今天的8点，则修改为明天的8点
        if (now.after(scheduleTime)) {
            scheduleTime.add(Calendar.DATE, 1);
        }

        // 计算初始延迟时间
        long initialDelay = scheduleTime.getTimeInMillis() - now.getTimeInMillis();
        timer.scheduleAtFixedRate(task1, initialDelay,24 * 60 * 60 * 1000, TimeUnit.SECONDS);
    }
    public static class MyTask implements Runnable {
        @Override
        public void run() {
        //执行的业务逻辑
            System.out.println("执行的业务逻辑.......");
        }
    }
}