CompletableFuture超时用法

/**
  * 接收到lpn:如果5s内接收到iu，那就返回lpn:iu;否则返回lpn
  * 接收到iu:如果5s内没接收到lpn，那就返回lpn:iu；否则返回iu
  *
  *
  * @author hyu
  */

 @RequestMapping("/test")
 @RestController
 public class TestController {
     private static ScheduledFuture timeOutFuture = null;
     private static final ScheduledExecutorService scheduler = Executors.newScheduledThreadPool(1);
     private static CompletableFuture lpnFuture ;
     private static CompletableFuture iuFuture ;
     private static CompletableFuture iuLpnFuture;

     @GetMapping("/setLpn")
     public ResponseEntity