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

//
//	For example: ceb8853ddc5086cc4ab9e149f8f09c88-5
//
// However, this scheme is only used for multipart objects that are
// not encrypted.
//
// # Server-side Encryption
//
// S3 specifies three types of server-side-encryption - SSE-C, SSE-S3
// and SSE-KMS - with different semantics w.r.t. ETags.
// In case of SSE-S3, the ETag of an object is computed the same as

<font color="#4E9A06">INFO</font>:     Started reloader process [<font color="#34E2E2"><b>2265862</b></font>] using <font color="#34E2E2"><b>WatchFiles</b></font>
<font color="#4E9A06">INFO</font>:     Started server process [<font color="#06989A">2265873</font>]
<font color="#4E9A06">INFO</font>:     Waiting for application startup.
<font color="#4E9A06">INFO</font>:     Application startup complete.
```

</div>

Sie senden ihm ein Token und er gibt einen authentifizierten Benutzer zurück.

Dieser Anbieter berechnet Ihnen möglicherweise Gebühren pro <abbr title="Request – Anfrage: Daten, die der Client zum Server sendet">Request</abbr>, und der Aufruf könnte etwas länger dauern, als wenn Sie einen vordefinierten <abbr title="Platzhalter, vorgetäuscht, zum Schein">Mock</abbr>-Benutzer für Tests hätten.

        V42
    }

    /**
     * Gets the identifier of the model from which the problem originated. The identifier is derived from the
     * information that is available at the point the problem occurs and as such merely serves as best effort
     * to provide information to the user to track the problem back to its origin.
     *
     * @return The identifier of the model from which the problem originated or an empty string if unknown, never

  set -e ; # fail if we can't read the keys.
  ACCESS=$(cat /config/rootUser) ; SECRET=$(cat /config/rootPassword) ;
  set +e ; # The connections to minio are allowed to fail.
  echo "Connecting to MinIO server: $SCHEME://$MINIO_ENDPOINT:$MINIO_PORT" ;
  MC_COMMAND="${MC} alias set myminio $SCHEME://$MINIO_ENDPOINT:$MINIO_PORT $ACCESS $SECRET" ;
  $MC_COMMAND ;
  STATUS=$? ;
  until [ $STATUS = 0 ]
  do

	Close() error

	// Is the underlying connection online? (is always true for any local lockers)
	IsOnline() bool

	// Is the underlying locker local to this server?
	IsLocal() bool

import org.apache.maven.api.annotations.Experimental;
import org.apache.maven.api.annotations.Nonnull;

/**
 * Manages the organization and access of artifacts within the local Maven repository.
 * The local repository serves as a cache for downloaded remote artifacts and storage
 * for locally installed artifacts. This manager provides services to determine the
 * appropriate paths for artifacts within the local repository structure.
 *

	LIMIT=29 # Allow 30 attempts
	set -e   # fail if we can't read the keys.
	ACCESS=$(cat /config/rootUser)
	SECRET=$(cat /config/rootPassword)
	set +e # The connections to minio are allowed to fail.
	echo "Connecting to MinIO server: $SCHEME://$MINIO_ENDPOINT:$MINIO_PORT"
	MC_COMMAND="${MC} alias set myminio $SCHEME://$MINIO_ENDPOINT:$MINIO_PORT $ACCESS $SECRET"
	$MC_COMMAND
	STATUS=$?
	until [ $STATUS = 0 ]; do
		ATTEMPTS=$(expr $ATTEMPTS + 1)

Wenn Sie dieses Beispiel ausführen und auf <a href="http://127.0.0.1:8000/items/foo" class="external-link" target="_blank">http://127.0.0.1:8000/items/foo</a> gehen, sehen Sie als <abbr title="Response – Antwort: Daten, die der Server zum anfragenden Client zurücksendet">Response</abbr>:

```JSON
{"item_id":"foo"}
```

## Pfad-Parameter mit Typen { #path-parameters-with-types }