java计时器

import java.text.SimpleDateFormat;import java.util.Calendar;import java.util.Date;import java.util.Timer;import java.util.TimerTask;//系统方法TimerTask，实现接口是Runnableclass Mytimer extends TimerTask {public void run() {new Timer().schedule(new Mytimer(),2000);//创建一个定时器,每两秒输出一次SimpleDateFormat df = new SimpleDateFormat("yyyy-MM-dd HH:mm:ss");//设置日期格式System.out.println(df.format(new Date()));// new Date()为获取当前系统时间System.out.println("helloworld");}}public class CountTimer {public static void main(String[] args) {Mytimer mytimer = new Mytimer();Thread t1 = new Thread(mytimer);t1.start();}}