Spring mvc异步处理

悠悠 2022-01-28 11:57 208阅读 0赞

# [Spring mvc异步处理][Spring mvc] #

基于Servlet3.0的异步处理，springmvc的异步处理

控制器返回callable， spring mvc异步处理，将callable提交到TaskExecutor  使用一个隔离线程进行执行

DispatcherServlet和所有的Filter退出web容器的线程，但是response保持打开状态

Callable返回结果， Spring mvc 将请求重新派发给容器，回复之前的处理

根据Callable返回的结果，Springmvc继续进行视图渲染流程等（从收请求一直到视图渲染）

![1179709-20190414163332901-1172315361.png][]

两次 preHandler哦

异步拦截器：

1 原生API的AsyncListener

2 Spring mvc 实现AsyncHandlerInterceptor

消息中间件的方式：

![1179709-20190414164446040-682461533.png][]

Spring mvc也有这样的类似的机制

Controller：

@Controller
    public class SpringMVCAsyncController {
        @ResponseBody 
        @RequestMapping("/createOrder")
        public DeferredResult<Object> createOrder(){  //3秒没有响应 就报错
            DeferredResult<Object> deferredResult = new DeferredResult<Object>((long)3000, "error: create fail...");
            DeferredResultQueue.save(deferredResult);
            return deferredResult;
        }
        @ResponseBody
        @RequestMapping("/create")
        public String create() {
            //创建订单
            String orderNum = UUID.randomUUID().toString();
            //拿出上面保存的DeferredResultQueue
             DeferredResult<Object> deferredResult = DeferredResultQueue.get();
             deferredResult.setResult(orderNum); //设置订单号createOrder() 就会得到立即返回
            return "success===>orderNum:"+orderNum;
        }
        
    }

队列：

public class DeferredResultQueue {
        
       private static Queue<DeferredResult<Object>>    queue = new ConcurrentLinkedQueue<DeferredResult<Object>>();
        
       public static void save(DeferredResult<Object> deferredResult) {
           queue.add(deferredResult);
       }
       
       public static DeferredResult<Object> get() {
          return queue.poll();
       }
    }

请求： 3秒没有赋值 就报错哈

![1179709-20190414171317170-119873955.png][]

posted @ 2019-04-14 17:14 [toov5][] 阅读(...) 评论(...) [编辑][Link 1] 收藏

[Spring mvc]: https://www.cnblogs.com/toov5/p/10705919.html
[1179709-20190414163332901-1172315361.png]: /images/20220128/1e0afb32b32d40e5ba47983afb114ffb.png
[1179709-20190414164446040-682461533.png]: /images/20220128/3a505d61b0ed48c9aeb5a53d48ce58c8.png
[1179709-20190414171317170-119873955.png]: /images/20220128/62b35e7581844ffba3b0d0cacfbdf9d0.png
[toov5]: https://www.cnblogs.com/toov5/
[Link 1]: https://i.cnblogs.com/EditPosts.aspx?postid=10705919