distributors to deny you these rights or to ask you to surrender these
rights.  These restrictions translate to certain responsibilities for
you if you distribute copies of the library or if you modify it.

  For example, if you distribute copies of the library, whether gratis
or for a fee, you must give the recipients all the rights that we gave
you.  You must make sure that they, too, receive or can get the source

{* ../../docs_src/advanced_middleware/tutorial002_py39.py hl[2,6:8] *}

Die folgenden Argumente werden unterstützt:

* `allowed_hosts` – Eine Liste von Domain-Namen, die als Hostnamen zulässig sein sollten. Wildcard-Domains wie `*.example.com` werden unterstützt, um Subdomains zu matchen. Um jeden Hostnamen zu erlauben, verwenden Sie entweder `allowed_hosts=["*"]` oder lassen Sie diese Middleware weg.

El `TestClient` está basado en <a href="https://www.python-httpx.org" class="external-link" target="_blank">HTTPX</a>, y afortunadamente, podemos usarlo directamente para probar la API.

## Ejemplo { #example }

A Gradle platform is a logical distribution that provides support for a specific kind of automation.
A typical platform builds on other platforms in order to add more capabilities, for example, to add support for a particular language.

See the [discovery document](https://docs.google.com/document/d/1-oKG23gLdx2D2uJvzir31AhDFyqSf81LDESfKKCU28c/edit#heading=h.pps74pn68uvk) (internal document) for more context.

Avoid writing the so-called `PolyNull` or `ParametricNull` methods (where nullability of the result depends on the nullability of the type argument).

这个操作一般只需要在最开始执行一次。

/// tip

域名这部分发生在 HTTPS 之前，由于这一切都依赖于域名和 IP 地址，所以先在这里提一下。

///

### DNS

现在让我们关注真正的 HTTPS 部分。

首先，浏览器将通过 **DNS 服务器** 查询**域名的IP** 是什么，在本例中为 `someapp.example.com`。

DNS 服务器会告诉浏览器使用某个特定的 **IP 地址**。 这将是你在 DNS 服务器中为你的服务器配置的公共 IP 地址。

<img src="/img/deployment/https/https01.drawio.svg">

### TLS 握手开始

然后，浏览器将在**端口 443**（HTTPS 端口）上与该 IP 地址进行通信。

  var sslSocketFactory: SSLSocketFactory? = handshakeCertificates.sslSocketFactory()
  var hostnameVerifier: HostnameVerifier? = HttpsURLConnection.getDefaultHostnameVerifier()
  var uriHost: String = "example.com"
  var uriPort: Int = 1

  fun newConnection(
    pool: RealConnectionPool,
    route: Route,
    idleAtNanos: Long = Long.MAX_VALUE,
    taskRunner: TaskRunner = this.taskRunner,
  ): RealConnection {

Just use any kind of model, any kind of class, any kind of database that you need for your application. **FastAPI** has you covered with the dependency injection system.

## Code size { #code-size }

This example might seem verbose. Keep in mind that we are mixing security, data models, utility functions and *path operations* in the same file.

But here's the key point.

The security and dependency injection stuff is written once.

{* ../../docs_src/advanced_middleware/tutorial002_py39.py hl[2,6:8] *}

Os seguintes argumentos são suportados:

* `allowed_hosts` - Uma lista de nomes de domínio que são permitidos como nomes de host. Domínios com coringa, como `*.example.com`, são suportados para corresponder a subdomínios. Para permitir qualquer nome de host, use `allowed_hosts=["*"]` ou omita o middleware.

## `TrustedHostMiddleware`

强制所有传入请求都必须正确设置 `Host` 请求头，以防 HTTP 主机头攻击。

{* ../../docs_src/advanced_middleware/tutorial002.py hl[2,6:8] *}

支持以下参数：

* `allowed_hosts` - 允许的域名（主机名）列表。`*.example.com` 等通配符域名可以匹配子域名，或使用 `allowed_hosts=["*"]` 允许任意主机名，或省略中间件。

如果传入的请求没有通过验证，则发送 `400` 响应。

## `GZipMiddleware`

处理 `Accept-Encoding` 请求头中包含 `gzip` 请求的 GZip 响应。

中间件会处理标准响应与流响应。