以及如何[使用 `CORSMiddleware` 处理 CORS](../tutorial/cors.md){.internal-link target=_blank}。

本章学习如何使用其它中间件。

## 添加 ASGI 中间件

因为 **FastAPI** 基于 Starlette，且执行 <abbr title="Asynchronous Server Gateway Interface，异步服务器网关界面">ASGI</abbr> 规范，所以可以使用任意 ASGI 中间件。

中间件不必是专为 FastAPI 或 Starlette 定制的，只要遵循 ASGI 规范即可。

总之，ASGI 中间件是类，并把 ASGI 应用作为第一个参数。

因此，有些第三方 ASGI 中间件的文档推荐以如下方式使用中间件：

```Python

In this section we'll see how to use other middlewares.

## Adding ASGI middlewares

As **FastAPI** is based on Starlette and implements the <abbr title="Asynchronous Server Gateway Interface">ASGI</abbr> specification, you can use any ASGI middleware.

A middleware doesn't have to be made for FastAPI or Starlette to work, as long as it follows the ASGI spec.

   */
  fun cancel()

  fun interface Factory {
    /**
     * Creates a new web socket and immediately returns it. Creating a web socket initiates an
     * asynchronous process to connect the socket. Once that succeeds or fails, `listener` will be
     * notified. The caller must either close or cancel the returned web socket when it is no longer
     * in use.
     */

  }

  /**
   * An object that holds the final result of an asynchronous {@link ClosingFuture} operation and
   * allows the user to close all the closeable objects that were captured during it for later
   * closing.
   *
   * <p>The asynchronous operation will have completed before this object is created.
   *
   * @param <V> the type of the value of a successful operation

dökümantasyon için Pydantic gibi bir üçüncü parti kütüphane kullanmıyor, kendi içerisinde bunlara sahip. Yani bu veri tipi tanımlarını tekrar kullanmak pek de kolay değil.

Biraz daha detaylı ayarlamalara gerek duyuyor. Ayrıca <abbr title="ASGI (Asynchronous Server Gateway Interface): Asenkron Sunucu Ağ Geçidi Arabirimi, asenkron Python web uygulamaları geliştirmek için yeni standart.">ASGI</abbr> yerine <abbr title="WSGI (Web Server Gateway Interface): Web Sunucusu Ağ Geçidi Arabirimi, Pythonda senkron...

import com.google.errorprone.annotations.DoNotMock;
import java.util.concurrent.Executor;
import java.util.concurrent.TimeUnit;
import java.util.concurrent.TimeoutException;

/**
 * An object with an operational state, plus asynchronous {@link #startAsync()} and {@link
 * #stopAsync()} lifecycle methods to transition between states. Example services include
 * webservers, RPC servers and timers.
 *
 * <p>The normal lifecycle of a service is:
 *

 * try (Response response = call.execute()) {
 * ... // Use the response.
 * }
 * ```
 *
 * You can use a similar block for asynchronous calls:
 *
 * ```java
 * Call call = client.newCall(request);
 * call.enqueue(new Callback() {
 *   public void onResponse(Call call, Response response) throws IOException {
 *     try (ResponseBody responseBody = response.body()) {
 *     ... // Use the response.

   dropped in 2.0.

## Version 1.5.4

_2014-04-14_

 * Drop ALPN support in Android. There's a concurrency bug in all
   currently-shipping versions.
 * Support asynchronous disconnects by breaking the socket only. This should
   prevent flakiness from multiple threads concurrently accessing a stream.

## Version 1.5.3

_2014-03-29_

///

/// tip

If you want to call `async` functions in your tests apart from sending requests to your FastAPI application (e.g. asynchronous database functions), have a look at the [Async Tests](../advanced/async-tests.md){.internal-link target=_blank} in the advanced tutorial.

///

## Separating tests

        }
      }
    ```

### Asynchronous Get ([.kt][AsynchronousGetKotlin], [.java][AsynchronousGetJava])

Download a file on a worker thread, and get called back when the response is readable. The callback is made after the response headers are ready. Reading the response body may still block. OkHttp doesn't currently offer asynchronous APIs to receive a response body in parts.