public class MyTimerTask {    
    public static void main(String[] args) {        
        // 定義一個(gè)任務(wù)       
        TimerTask timerTask = new TimerTask() {            
        @Override            
            public void run() {                
            System.out.println("打印當(dāng)前時(shí)間：" + new Date());    
            }       
         };        
        // 計(jì)時(shí)器       
        Timer timer = new Timer();       
        // 開始執(zhí)行任務(wù) (延遲1000毫秒執(zhí)行，每3000毫秒執(zhí)行一次)        
        timer.schedule(timerTask, 1000, 3000);    
    }
}

public class MyScheduledExecutorService {    
    public static void main(String[] args) {        
        // 創(chuàng)建任務(wù)隊(duì)列   10 為線程數(shù)量      
        ScheduledExecutorService scheduledExecutorService = 
                Executors.newScheduledThreadPool(10); 
        // 執(zhí)行任務(wù)      
        scheduledExecutorService.scheduleAtFixedRate(() -> {          
            System.out.println("打印當(dāng)前時(shí)間：" + new Date());      
        }, 1, 3, TimeUnit.SECONDS); // 1s 后開始執(zhí)行，每 3s 執(zhí)行一次   
 
  }
}

@SpringBootApplication
@EnableScheduling //開啟定時(shí)任務(wù)
public class DemoApplication {  
     // --  -- 
}

import org.springframework.scheduling.annotation.Scheduled;
import org.springframework.stereotype.Component;
@Component // 把此類托管給 Spring，不能省略
public class TaskUtils {    
    // 添加定時(shí)任務(wù)    
    @Scheduled(cron = "30 40 23 0 0 5") // cron表達(dá)式：每周一 23:40:30 執(zhí)行    
    public void doTask(){        
        System.out.println("我是定時(shí)任務(wù)~");    
    }
}

import redis.clients.jedis.Jedis;
import utils.JedisUtils;
import java.time.Instant;
import java.util.Set;
public class DelayQueueExample {        
    private static final String _KEY = "DelayQueueExample";        
    public static void main(String[] args) throws InterruptedException {        
        Jedis jedis = JedisUtils.getJedis();        
        // 30s 后執(zhí)行        
        long delayTime = Instant.now().plusSeconds(30).getEpochSecond();       
        jedis.zadd(_KEY, delayTime, "order_1");        
        // 繼續(xù)添加測試數(shù)據(jù)        
       jedis.zadd(_KEY, Instant.now().plusSeconds(2).getEpochSecond(), "order_2");       
      jedis.zadd(_KEY, Instant.now().plusSeconds(2).getEpochSecond(), "order_3");        
      jedis.zadd(_KEY, Instant.now().plusSeconds(7).getEpochSecond(), "order_4");        
     jedis.zadd(_KEY, Instant.now().plusSeconds(10).getEpochSecond(), "order_5");        
        // 開啟定時(shí)任務(wù)隊(duì)列        
        doDelayQueue(jedis);    
    }    
    /**     
    * 定時(shí)任務(wù)隊(duì)列消費(fèi)     
    * @param jedis Redis 客戶端     
    */    
    public static void doDelayQueue(Jedis jedis) throws InterruptedException {        
        while (true) {            
            // 當(dāng)前時(shí)間            
            Instant nowInstant = Instant.now();            
            long lastSecond = nowInstant.plusSeconds(-1).getEpochSecond(); 
            // 上一秒時(shí)間            
            long nowSecond = nowInstant.getEpochSecond();            
            // 查詢當(dāng)前時(shí)間的所有任務(wù)            
            Set data = jedis.zrangeByScore(_KEY, lastSecond, nowSecond);            
            for (String item : data) {                
            // 消費(fèi)任務(wù)                
            System.out.println("消費(fèi)：" + item);            
        }            
        // 刪除已經(jīng)執(zhí)行的任務(wù)            
        jedis.zremrangeByScore(_KEY, lastSecond, nowSecond);            
        Thread.sleep(1000); // 每秒查詢一次        
        }    
    }
}

import redis.clients.jedis.Jedis;
import redis.clients.jedis.JedisPubSub;
import utils.JedisUtils;
public class TaskExample {    
    public static final String _TOPIC = "__keyevent@0__:expired"; // 訂閱頻道名稱   
    public static void main(String[] args) {       
        Jedis jedis = JedisUtils.getJedis();       
        // 執(zhí)行定時(shí)任務(wù)        
        doTask(jedis);    
    }   
     /**     
       * 訂閱過期消息，執(zhí)行定時(shí)任務(wù)     
       * @param jedis Redis 客戶端     
       */    
    public static void doTask(Jedis jedis) {        
        // 訂閱過期消息        
        jedis.psubscribe(new JedisPubSub() {            
            @Override            
 public void onPMessage(String pattern, String channel, String message) {                
            // 接收到消息，執(zhí)行定時(shí)任務(wù)                
            System.out.println("收到消息：" + message);            
            }            
        }, _TOPIC);    
    }
}