<img src="/img/tutorial/websockets/image05.png">

## Обработка отключений и работа с несколькими клиентами

Если веб-сокет соединение закрыто, то `await websocket.receive_text()` вызовет исключение `WebSocketDisconnect`, которое можно поймать и обработать как в этом примере:

{* ../../docs_src/websockets/tutorial003_py39.py hl[79:81] *}

Чтобы воспроизвести пример:

Par exemple, pour déclarer un paramètre de requête `q` qui peut apparaître plusieurs fois dans une URL, on écrit :

{* ../../docs_src/query_params_str_validations/tutorial011.py hl[9] *}

Ce qui fait qu'avec une URL comme :

```
http://localhost:8000/items/?q=foo&q=bar
```

And it has the same shape and structure that all your *path operation functions* have.

You can think of it as a *path operation function* without the "decorator" (without the `@app.get("/some-path")`).

And it can return anything you want.

In this case, this dependency expects:

* An optional query parameter `q` that is a `str`.
* An optional query parameter `skip` that is an `int`, and by default is `0`.

                        }
                    }
                } finally {
                    latch.countDown();
                }
            });
        }

        assertTrue(latch.await(10, TimeUnit.SECONDS), "Concurrent ops should complete");
        executor.shutdown();

        assertEquals(threadCount * operationsPerThread, successCount.get(), "All operations should succeed");
    }

    @Test

            final int threadId = i;
            executor.submit(new Runnable() {
                @Override
                public void run() {
                    try {
                        startLatch.await();
                        for (int j = 0; j < operationsPerThread; j++) {
                            // Transform operation
                            ResponseData responseData = new ResponseData();

    change OkHttp's behavior in handling common HTTP status codes, but this fix is overdue! The new
    behavior is now consistent with [RFC 7231][rfc_7231_647], which is newer than OkHttp itself.
    If you want this update with the old behavior use [this interceptor][legacy_interceptor].

 *  Fix: Don't crash decompressing web sockets messages. We had a bug where we assumed deflated

async def read_item(item_id: int, q: Optional[str] = None):
    return {"item_id": item_id, "q": q}
```

**توجه**:

اگر با `async / await` آشنا نیستید، به بخش _"عجله‌ دارید?"_ در صفحه درباره <a href="https://fastapi.tiangolo.com/async/#in-a-hurry" target="_blank">`async` و `await` در مستندات</a> مراجعه کنید.


</details>

### اجرا کنید

با استفاده از دستور زیر سرور را اجرا کنید:

<div class="termy">

def read_item(item_id: int, q: Union[str, None] = None):
    return {"item_id": item_id, "q": q}
```

<details markdown="1">
<summary>또는 <code>async def</code> 사용하기...</summary>

여러분의 코드가 `async` / `await`을 사용한다면, `async def`를 사용하십시오.

```Python hl_lines="9 14"
from typing import Union

from fastapi import FastAPI

app = FastAPI()


@app.get("/")
async def read_root():

          ) {
            processResponse(response, hostname, responses, failures)
            latch.countDown()
          }
        },
      )
    }

    try {
      latch.await()
    } catch (e: InterruptedException) {
      failures.add(e)
    }
  }

  private fun processResponse(
    response: Response,
    hostname: String,
    results: MutableList<InetAddress>,

        public @Nullable Object apply(Optional<?> optional) {
          return optional.orNull();
        }
      };

  /**
   * Sets.cartesianProduct doesn't allow sets that contain null, but we want null to mean "don't
   * call the associated CacheBuilder method" - that is, get the default CacheBuilder behavior. This
   * method wraps the elements in the input sets (which may contain null) as Optionals, calls