1、QueueTaskService接口层

public interface QueueTaskService {String offer(String userId);void poll();
}

2、QueueTaskServiceImpl实现层

@Service
public class QueueTaskServiceImpl implements QueueTaskService {private static final Queue<String> QUEUE = new ArrayBlockingQueue<>(2);@Overridepublic String offer(String userId) {boolean offer = QUEUE.offer(userId);// 1、判断本轮是否已经不再接收人数// 2、判断队列是否已满if (!offer) {return "当前排队人数较多，请稍后再试试！！";}return "恭喜您，入队成功！！！！！";}@Overridepublic void poll() {QUEUE.poll();}}

3、QueueTask定时任务

@Slf4j
@Component
@EnableScheduling//可以在启动类上注解也可以在当前文件
public class QueueTask {@Autowiredprivate QueueTaskService queueTaskService;@Scheduled(cron = "0/30 * * * * ?")public void poll() {log.info(">>>>>>>>出队任务");queueTaskService.poll();}
}

4、QueueTaskController

@RestController
@RequestMapping("/queue")
public class QueueTaskController {@Autowiredprivate QueueTaskService queueTaskService;@GetMapping("/test")public String test(@RequestParam String userId) {return queueTaskService.offer(userId);}
}

5、结果

30秒内多次入队，入队超过2个，将打印

当前排队人数较多，请稍后再试试！！