///

## What is "Form Data"

The way HTML forms (`<form></form>`) sends the data to the server normally uses a "special" encoding for that data, it's different from JSON.

**FastAPI** will make sure to read that data from the right place instead of JSON.

/// note | "Technical Details"

  // Set up a multi-client distributed execution environment. Must be called on
  // all tasks in the cluster.
  // This call internally coordinates with other tasks to initialize the eager
  // context and TF server for multi-client execution.
  virtual absl::Status EnableCollectiveOps(const ServerDef& server_def) = 0;

  // Set a distributed manager that helps set up, update, and check liveness
  // of member tasks in the cluster.

	errInvalidSSEParameters           = errors.New("The SSE-C key for key-rotation is not correct") // special access denied
	errKMSNotConfigured               = errors.New("KMS not configured for a server side encrypted objects")
	errKMSKeyNotFound                 = errors.New("Unknown KMS key ID")
	errKMSDefaultKeyAlreadyConfigured = errors.New("A default encryption already exists on KMS")

<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>

<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>

	//
	// TODO(aead): refactor this API call. It does not account
	// for multiple endpoints.
	Version(context.Context) (string, error)

	// APIs returns a list of APIs supported by the KMS server.
	//
	// TODO(aead): remove this API call. It's hardly useful.
	APIs(context.Context) ([]madmin.KMSAPI, error)

	// Stat returns the current KMS status.
	Status(context.Context) (map[string]madmin.ItemState, error)

	if target.closeErr {
		return errors.New("close error")
	}

	return nil
}

func (target ExampleTarget) IsActive() (bool, error) {
	return false, errors.New("not connected to target server/service")
}

// FlushQueueStore - No-Op. Added for interface compatibility
func (target ExampleTarget) FlushQueueStore() error {
	return nil
}

func TestTargetListAdd(t *testing.T) {

/**
 * 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:
 *
 * <ul>
 *   <li>{@linkplain State#NEW NEW} -&gt;
 *   <li>{@linkplain State#STARTING STARTING} -&gt;
 *   <li>{@linkplain State#RUNNING RUNNING} -&gt;

import javax.net.ssl.SSLSession
import okhttp3.internal.immutableListOf
import okhttp3.internal.toImmutableList

/**
 * A record of a TLS handshake. For HTTPS clients, the client is *local* and the remote server is
 * its *peer*.
 *
 * This value object describes a completed handshake. Use [ConnectionSpec] to set policy for new
 * handshakes.
 */
class Handshake internal constructor(
  /**

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