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

CI=on MINIO_KMS_SECRET_KEY=minio-default-key:IyqsU3kMFloCNup4BsZtf/rmfHVcTgznO2F25CkEH1g= MINIO_ROOT_USER=minio MINIO_ROOT_PASSWORD=minio123 minio server --certs-dir /tmp/certs --address ":9002" --console-address ":11000" /tmp/minio2/{1...4}/disk{1...4}...

   * acquire(3) arrives. We serve this request out of storedPermits, and reduce that to 7.0 (how
   * this is translated to throttling time is discussed later). Immediately after, assume that an
   * acquire(10) request arriving. We serve the request partly from storedPermits, using all the
   * remaining 7.0 permits, and the remaining 3.0, we serve them by fresh permits produced by the
   * rate limiter.
   *

在示例代码的情况下，客户端将会收到 *HTTP 500 Internal Server Error* 的响应，因为我们没有抛出 `HTTPException` 或者类似的异常，并且服务器也 **不会有任何日志** 或者其他提示来告诉我们错误是什么。😱

### 在包含 `yield` 和 `except` 的依赖项中一定要 `raise`

如果你在使用 `yield` 的依赖项中捕获到了一个异常，你应该再次抛出捕获到的异常，除非你抛出 `HTTPException` 或类似的其他异常，

你可以使用 `raise` 再次抛出捕获到的异常。

{* ../../docs_src/dependencies/tutorial008d_an_py39.py hl[17] *}

现在客户端同样会得到 *HTTP 500 Internal Server Error* 响应，但是服务器日志会记录下我们自定义的 `InternalError`。

import jcifs.internal.smb2.Smb2Constants;
import jcifs.internal.util.SMBUtil;

/**
 * SMB2 Set Info request message. This command is used to modify file attributes,
 * security information, or other metadata on the server.
 *
 * @author mbechler
 *
 */
public class Smb2SetInfoRequest extends ServerMessageBlock2Request<Smb2SetInfoResponse> implements RequestWithFileId {

    private byte[] fileId;
    private byte infoType;

<span style="color: green;">INFO</span>:     Uvicorn running on http://127.0.0.1:8000 (Press CTRL+C to quit)
<span style="color: green;">INFO</span>:     Started reloader process [28720]
<span style="color: green;">INFO</span>:     Started server process [28722]
<span style="color: green;">INFO</span>:     Waiting for application startup.
<span style="color: green;">INFO</span>:     Application startup complete.
```

</div>

В этом разделе посмотрим, как использовать другие middleware.

## Добавление ASGI middleware { #adding-asgi-middlewares }

Так как **FastAPI** основан на Starlette и реализует спецификацию <abbr title="Asynchronous Server Gateway Interface – Асинхронный шлюзовой интерфейс сервера">ASGI</abbr>, вы можете использовать любое ASGI middleware.

        ],
        "parallelizationMethod": {
          "name": "TestDistribution"
        }
      },
      {
        "subprojects": [
          "concurrent",
          "daemon-protocol",
          "daemon-server-worker",
          "functional",
          "internal-instrumentation-api",
          "java-api-extractor",
          "java-compiler-plugin",
          "javadoc",
          "kotlin-dsl-integ-tests",

    val jacksonKotlin = "com.fasterxml.jackson.module:jackson-module-kotlin"
    val jetty = "org.eclipse.jetty:jetty-http"
    val jettySecurity = "org.eclipse.jetty:jetty-security"
    val jettyServer = "org.eclipse.jetty:jetty-server"
    val jettyServlet = "org.eclipse.jetty:jetty-servlet"
    val jettyUtil = "org.eclipse.jetty:jetty-util"
    val jettyWebApp = "org.eclipse.jetty:jetty-webapp"
    val joptSimple = "net.sf.jopt-simple:jopt-simple"

        // Given: A non-workgroup type with a host
        when(locator.getType()).thenReturn(SmbConstants.TYPE_SERVER);
        when(locator.getURL()).thenReturn(createSmbURL("smb://server/"));

        // When & Then: Constructor should throw SmbException
        SmbException exception = assertThrows(SmbException.class, () -> new NetServerEnumIterator(parent, treeHandle, "*", 0, null));