学步园

OneHour.java类：

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

public class OneHour {

	private final static long JOB_INTERNAL = 1000 * 60 * 60;//隔一个小时运行一次，如果是测试，可以改小一点

	public static void main(String[] args) {
		Timer timer = new Timer();

		Calendar currentTime = Calendar.getInstance();
		currentTime.setTime(new Date());

		int currentHour = currentTime.get(Calendar.HOUR);

		currentTime.set(Calendar.HOUR, currentHour + 1);
		currentTime.set(Calendar.MINUTE, 0);
		currentTime.set(Calendar.SECOND, 0);
		currentTime.set(Calendar.MILLISECOND, 0);

		//下面几行是相隔时间短一点的测试代码
		/*
		currentTime.set(Calendar.HOUR, currentTime.get(Calendar.HOUR));
		currentTime.set(Calendar.MINUTE, currentTime.get(Calendar.MINUTE));
		currentTime.set(Calendar.SECOND, currentTime.get(Calendar.SECOND));
		currentTime.set(Calendar.MILLISECOND, currentTime.get(Calendar.MILLISECOND));
		*/

		Date NextHour = currentTime.getTime();
		System.out.println(NextHour);

		timer.scheduleAtFixedRate(new MyTask(), NextHour, JOB_INTERNAL);
	}
}

MyTask.java类：

import java.util.Date;
import java.util.TimerTask;

class MyTask extends TimerTask {

	@Override
	public void run() {
		System.out.println("mytask： " + new Date());
		
		try {
			Thread.sleep(10000);	//设置让它休眠一段时间，测试下一次运行时间是否还是整点
		} catch (InterruptedException e) {
			e.printStackTrace();
		}
	}

}