spring boot高并发下耗时操作的实现方法

http1    http2        http3
thread1  thread2      thread3

  /**
   * 异步建立高并发的订单.
   *
   * @return
   */
  @GetMapping("/create-order")
  public DeferredResult<Object> createOrder() {
    DeferredResult<Object> deferredResult = new DeferredResult<>((long) 3000, "error order");
    logger.info("发布建立订单的事件");
    applicationEventPublisher.publishEvent(deferredResult);
    return deferredResult;
  }

@Component
@EnableAsync
public class OrderListener {

  static Logger logger = LoggerFactory.getLogger(OrderListener.class);

  /**
   * 事实上它是一个订单队列的消费者，在后台写订单，本例使用简单的事件监听器实现异步处理的功能.
   *
   * @return
   */
  @EventListener
  @Async
  public String processOrder(DeferredResult<Object> deferredResult) throws InterruptedException {
    logger.info("处理订单并返回到对应的Http上下文");
    String order = UUID.randomUUID().toString();
    Thread.sleep(2000);//假设处理数据需要5秒，前端需要阻塞5秒，但http主线程已经释放了，比较适合IO密集型场合
    //当设置之后，create-order将成功响应
    deferredResult.setResult(order);
    return order;
  }
}