如何写一个定时任务的线程？

主题：java 中怎么实现定时任务？

Thread Sleep

public class Task1 {
public static void main(String[] args) {
  final long timeInterval = 1000;
  Runnable runnable = new Runnable() {
  public void run() {
    while (true) {
      System.out.println("Hello !!");
      try {
       Thread.sleep(timeInterval);
      } catch (InterruptedException e) {
        e.printStackTrace();
      }
      }
    }
  };
  Thread thread = new Thread(runnable);
  thread.start();
  }
}

TimerTask

import java.util.Timer;
import java.util.TimerTask;
public class Task2 {
  public static void main(String[] args) {
    TimerTask task = new TimerTask() {
      @Override
      public void run() {
        System.out.println("Hello !!!");
      }
    };
    Timer timer = new Timer();
    long delay = 0;
    long intevalPeriod = 1 * 1000; 
    timer.scheduleAtFixedRate(task, delay,
                                intevalPeriod);
  } 
}

ScheduledExecutorService

import java.util.concurrent.Executors;
import java.util.concurrent.ScheduledExecutorService;
import java.util.concurrent.TimeUnit;
public class Task3 {
  public static void main(String[] args) {
    Runnable runnable = new Runnable() {
      public void run() {
        System.out.println("Hello !!");
      }
    };
    ScheduledExecutorService service = Executors
                    .newSingleThreadScheduledExecutor();
    service.scheduleAtFixedRate(runnable, 0, 1, TimeUnit.SECONDS);
  }
}

Spring 注解

• @Scheduled
• @Async
• ...