Java延时执行的三种实现方式

public class TestDelay {
    public static void main(String[] args) {
        System.out.println("Start: " + System.currentTimeMillis());
        try {
            Thread.sleep(5000);   //延时5秒
        } catch (InterruptedException e) {
            e.printStackTrace();
        }
        System.out.println("End: " + System.currentTimeMillis());
    }
}

import java.util.Timer;
import java.util.TimerTask;

public class TimerTaskTest {
    public static void main(String[] args) {
        TimerTask task = new TimerTask() {
            @Override
            public void run() {
                System.out.println("Task executed");
            }
        };

        Timer timer = new Timer();
        timer.schedule(task, 5000);    // 在5秒内执行task
    }
}

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

public class ScheduledExecutorServiceTest {
    public static void main(String[] args) {
        ScheduledExecutorService executor = Executors.newScheduledThreadPool(1);
        executor.schedule(new Runnable() {
            @Override
            public void run() {
                System.out.println("Task executed");
            }
        }, 5, TimeUnit.SECONDS);    // 五秒钟后执行任务
        executor.shutdown();
    }
}