Java 延时队列及简单使用方式详解

@Data
static class SimpleDelayed<T> implements Delayed {
    /**
     * 对象创建时间
     */
    @JsonIgnore
    private final Date createDate;
    /**
     * 延时数（单位毫秒）
     */
    private long delayCount;
    private T data;
    public SimpleDelayed(T data, long delayCount) {
        this.data = data;
        this.delayCount = delayCount;
        this.createDate = new Date();
    }
    @Override
    public long getDelay(TimeUnit unit) {
        long diff = this.createDate.getTime() + this.delayCount - System.currentTimeMillis();
        return unit.convert(diff, TimeUnit.MILLISECONDS);
    }
    @Override
    public int compareTo(Delayed delayed) {
        return Long.compare(this.getDelay(TimeUnit.MILLISECONDS),delayed.getDelay(TimeUnit.MILLISECONDS));
    }
}

@Slf4j
public class SimpleDelayQueueUtils {
   /**
     * 1.定义了一个延时队列 队列中元素是我们的SimpleDelayed
     */
    private final static DelayQueue<SimpleDelayed> SIMPLE_DELAYED_DELAY_QUEUE = new DelayQueue<>();
    static{
      	// 2.声明一个异步线程
        CompletableFuture.runAsync(() -> {
          	// 3.通过自旋去出队已过期的元素
            for (;;) {
                try {
					// 4.take() 对头元素出队。
                    log.info("元素已过期{}",SIMPLE_DELAYED_DELAY_QUEUE.take().getData());
                } catch (InterruptedException e) {
                    throw new RuntimeException(e);
                }
            }
        // 单个线程的线程池，为了不占用fork-join线程池
        }, Executors.newSingleThreadExecutor());
    }
    public static void add(SimpleDelayed... delayeds) {
        SIMPLE_DELAYED_DELAY_QUEUE.addAll(Arrays.asList(delayeds));
    }
  	// 测试
    public static void main(String[] args) {
        SimpleDelayed<String> nonceDelayed = new SimpleDelayQueueUtils.SimpleDelayed<>("111",5001);
        SimpleDelayed<String> nonceDelayed1 = new SimpleDelayQueueUtils.SimpleDelayed<>("222", 4500);
        SimpleDelayQueueUtils.add(nonceDelayed,nonceDelayed1);
    }
}