延迟队列 【Delay Queue】
它是一种特定类型的 Java 集合，它允许我们根据元素的延迟时间对元素进行排序。老实说，这是一门非常有趣的课。尽管 DelayQueue该类是 Java 集合的成员，但它属于 java.util.concurrent 包。它实现了BlockingQueue接口。只有当元素的时间到期时，才能从队列中取出元素
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| public record DelayedEvent(long startTime, String msg) implements Delayed {
public long getDelay(TimeUnit unit) {
long diff = startTime - System.currentTimeMillis();
return unit.convert(diff, TimeUnit.MILLISECONDS);
}
public int compareTo(Delayed o) {
return (int) (this.startTime - ((DelayedEvent) o).startTime);
}
}
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假设我们想推迟元素10秒。我们只需要设置当前时间增加了10秒DelayedEvent类
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| final DelayQueue<DelayedEvent> delayQueue = new DelayQueue<>();
final long timeFirst = System.currentTimeMillis() + 10000;
delayQueue.offer(new DelayedEvent(timeFirst, "1"));
log.info("Done");
log.info(delayQueue.take().msg());
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