# WebSockets

Sie können <a href="https://developer.mozilla.org/en-US/docs/Web/API/WebSockets_API" class="external-link" target="_blank">WebSockets</a> mit **FastAPI** verwenden.

## `WebSockets` installieren

Zuerst müssen Sie `WebSockets` installieren:

<div class="termy">

```console
$ pip install websockets

---> 100%
```

</div>

## WebSockets-Client

### In Produktion

```

::: fastapi.WebSocketDisconnect

## WebSockets - additional classes

Additional classes for handling WebSockets.

Provided directly by Starlette, but you can import it from `fastapi`:

```python
from fastapi.websockets import WebSocketDisconnect, WebSocketState
```

::: fastapi.websockets.WebSocketDisconnect

```

::: fastapi.WebSocketDisconnect

## WebSockets – zusätzliche Klassen

Zusätzliche Klassen für die Handhabung von WebSockets.

Werden direkt von Starlette bereitgestellt, Sie können sie jedoch von `fastapi` importieren:

```python
from fastapi.websockets import WebSocketDisconnect, WebSocketState
```

::: fastapi.websockets.WebSocketDisconnect

# WebSockets

You can use <a href="https://developer.mozilla.org/en-US/docs/Web/API/WebSockets_API" class="external-link" target="_blank">WebSockets</a> with **FastAPI**.

## Install `WebSockets`

First you need to install `WebSockets`:

<div class="termy">

```console
$ pip install websockets

---> 100%
```

</div>

## WebSockets client

### In production

# WebSockets

您可以在 **FastAPI** 中使用 [WebSockets](https://developer.mozilla.org/en-US/docs/Web/API/WebSockets_API)。

## 安装 `WebSockets`

首先，您需要安装 `WebSockets`：

```console
$ pip install websockets

---> 100%
```

## WebSockets 客户端

### 在生产环境中

在您的生产系统中，您可能使用现代框架（如React、Vue.js或Angular）创建了一个前端。

要使用 WebSockets 与后端进行通信，您可能会使用前端的工具。

或者，您可能有一个原生移动应用程序，直接使用原生代码与 WebSocket 后端通信。

或者，您可能有其他与 WebSocket 终端通信的方式。

# 测试 WebSockets

测试 WebSockets 也使用 `TestClient`。

为此，要在 `with` 语句中使用 `TestClient` 连接 WebSocket。

```Python hl_lines="27-31"
{!../../../docs_src/app_testing/tutorial002.py!}
```

!!! note "笔记"

# WebSockets testen

Sie können den schon bekannten `TestClient` zum Testen von WebSockets verwenden.

Dazu verwenden Sie den `TestClient` in einer `with`-Anweisung, eine Verbindung zum WebSocket herstellend:

```Python hl_lines="27-31"
{!../../../docs_src/app_testing/tutorial002.py!}
```

!!! note "Hinweis"

 * limitations under the License.
 */
package okhttp3

import okio.ByteString

/**
 * A non-blocking interface to a web socket. Use the [factory][WebSocket.Factory] to create
 * instances; usually this is [OkHttpClient].
 *
 * ## Web Socket Lifecycle
 *
 * Upon normal operation each web socket progresses through a sequence of states:
 *

            webSockets.add(client.newWebSocket(request, clientListener))
            attempts.countDown()
          }
        }
      }
    clientListener.setNextEventDelegate(reconnectOnFailure)
    webSockets.add(client.newWebSocket(request, clientListener))
    attempts.await()
    synchronized(webSockets) {
      for (webSocket in webSockets) {
        webSocket.cancel()
      }
    }

    from fastapi import (
        Cookie,
        FastAPI,
        WebSocket,
        WebSocketException,
        status,
    )

    app = FastAPI()

    @app.websocket("/items/{item_id}/ws")
    async def websocket_endpoint(
        *,
        websocket: WebSocket,
        session: Annotated[str | None, Cookie()] = None,
        item_id: str,
    ):
        if session is None: