Java倒计时器的代码实现有哪些技巧

在Java中，实现倒计时器的方法有很多，以下是一些常见的技巧：

1. 使用Thread.sleep()方法：

public class CountdownTimer {     public static void main(String[] args) {         int seconds = 10;         for (int i = seconds; i >= 0; i--) {             System.out.println(i);             try {                 Thread.sleep(1000);             } catch (InterruptedException e) {                 e.printStackTrace();             }         }     } } 

2. 使用ScheduledExecutorService：

import java.util.concurrent.Executors; import java.util.concurrent.ScheduledExecutorService; import java.util.concurrent.TimeUnit;  public class CountdownTimer {     public static void main(String[] args) {         int seconds = 10;         ScheduledExecutorService executor = Executors.newScheduledThreadPool(1);         executor.scheduleAtFixedRate(() -> {             if (seconds > 0) {                 System.out.println(seconds--);             } else {                 executor.shutdown();             }         }, 0, 1, TimeUnit.SECONDS);     } } 

3. 使用CountDownLatch：

import java.util.concurrent.CountDownLatch; import java.util.concurrent.TimeUnit;  public class CountdownTimer {     public static void main(String[] args) {         int seconds = 10;         CountDownLatch latch = new CountDownLatch(seconds);         for (int i = 0; i< seconds; i++) {             new Thread(() -> {                 try {                     latch.await();                     System.out.println(seconds--);                 } catch (InterruptedException e) {                     e.printStackTrace();                 }             }).start();             latch.countDown();             try {                 TimeUnit.SECONDS.sleep(1);             } catch (InterruptedException e) {                 e.printStackTrace();             }         }     } } 

4. 使用CompletableFuture：

import java.util.concurrent.CompletableFuture; import java.util.concurrent.TimeUnit;  public class CountdownTimer {     public static void main(String[] args) {         int seconds = 10;         CompletableFuture.runAsync(() -> {             while (seconds >= 0) {                 System.out.println(seconds--);                 try {                     TimeUnit.SECONDS.sleep(1);                 } catch (InterruptedException e) {                     e.printStackTrace();                 }             }         });     } } 

这些技巧可以根据你的需求进行组合和修改。注意，当在生产环境中使用倒计时器时，请确保正确处理线程中断和异常。