*
 * Licensed under the Apache License, Version 2.0 (the "License");
 * you may not use this file except in compliance with the License.
 * You may obtain a copy of the License at
 *
 *      http://www.apache.org/licenses/LICENSE-2.0
 *
 * Unless required by applicable law or agreed to in writing, software
 * distributed under the License is distributed on an "AS IS" BASIS,

 *
 * Licensed under the Apache License, Version 2.0 (the "License");
 * you may not use this file except in compliance with the License.
 * You may obtain a copy of the License at
 *
 *      http://www.apache.org/licenses/LICENSE-2.0
 *
 * Unless required by applicable law or agreed to in writing, software
 * distributed under the License is distributed on an "AS IS" BASIS,

* クライアントがアクセスしようとしていた項目が存在しません。
* など

これらの場合、通常は **400**（400から499）の範囲内の **HTTPステータスコード** を返すことになります。

これは200のHTTPステータスコード（200から299）に似ています。これらの「200」ステータスコードは、何らかの形でリクエスト「成功」であったことを意味します。

400の範囲にあるステータスコードは、クライアントからのエラーがあったことを意味します。

**"404 Not Found"** のエラー（およびジョーク）を覚えていますか？

## `HTTPException`の使用

HTTPレスポンスをエラーでクライアントに返すには、`HTTPException`を使用します。

### `HTTPException`のインポート

from typing import Optional

from fastapi import FastAPI, Security
from fastapi.security.http import HTTPAuthorizationCredentials, HTTPBase
from fastapi.testclient import TestClient

app = FastAPI()

security = HTTPBase(scheme="Other", auto_error=False)


@app.get("/users/me")
def read_current_user(
    credentials: Optional[HTTPAuthorizationCredentials] = Security(security),
):
    if credentials is None:

# 自定义响应 - HTML，流，文件和其他

**FastAPI** 默认会使用 `JSONResponse` 返回响应。

你可以通过直接返回 `Response` 来重载它，参见 [直接返回响应](response-directly.md){.internal-link target=_blank}。

但如果你直接返回 `Response`，返回数据不会自动转换，也不会自动生成文档（例如，在 HTTP 头 `Content-Type` 中包含特定的「媒体类型」作为生成的 OpenAPI 的一部分）。

你还可以在 *路径操作装饰器* 中声明你想用的 `Response`。

你从 *路径操作函数* 中返回的内容将被放在该 `Response` 中。

 * Copyright (C) 2013 Square, Inc.
 *
 * Licensed under the Apache License, Version 2.0 (the "License");
 * you may not use this file except in compliance with the License.
 * You may obtain a copy of the License at
 *
 *      http://www.apache.org/licenses/LICENSE-2.0
 *
 * Unless required by applicable law or agreed to in writing, software
 * distributed under the License is distributed on an "AS IS" BASIS,

 * Copyright (C) 2024 Square, Inc.
 *
 * Licensed under the Apache License, Version 2.0 (the "License");
 * you may not use this file except in compliance with the License.
 * You may obtain a copy of the License at
 *
 *      http://www.apache.org/licenses/LICENSE-2.0
 *
 * Unless required by applicable law or agreed to in writing, software
 * distributed under the License is distributed on an "AS IS" BASIS,

 * Copyright (C) 2010 The Guava Authors
 *
 * Licensed under the Apache License, Version 2.0 (the "License");
 * you may not use this file except in compliance with the License.
 * You may obtain a copy of the License at
 *
 * http://www.apache.org/licenses/LICENSE-2.0
 *
 * Unless required by applicable law or agreed to in writing, software
 * distributed under the License is distributed on an "AS IS" BASIS,

version `0.122.0`, when the integrated security utilities returned an error to the client after a failed authentication, they used the HTTP status code `403 Forbidden`.

Starting with FastAPI version `0.122.0`, they use the more appropriate HTTP status code `401 Unauthorized`, and return a sensible `WWW-Authenticate` header in the response, following the HTTP specifications, <a href="https://datatracker.ietf.org/doc/html/rfc7235#section-3.1" class="external-link" target="_blank">RFC 7235</a>,...

os utilitários de segurança integrados retornavam um erro ao cliente após uma falha na autenticação, eles usavam o código de status HTTP `403 Forbidden`.

A partir da versão `0.122.0` do FastAPI, eles usam o código de status HTTP `401 Unauthorized`, mais apropriado, e retornam um cabeçalho `WWW-Authenticate` adequado na response, seguindo as especificações HTTP, <a href="https://datatracker.ietf.org/doc/html/rfc7235#section-3.1" class="external-link" target="_blank">RFC 7235</a>, <a href="h...