final String tokenUrl = getParameter(TOKEN_URL);
        final String tokenPattern = getParameter(TOKEN_PATTERN);
        final List<Pair<String, String>> responseParams = new ArrayList<>();
        final String encoding = getParameter(ENCODING);
        if (StringUtil.isNotBlank(tokenUrl) && StringUtil.isNotBlank(tokenPattern)) {

///

При создании экземпляра класса `OAuth2PasswordBearer` мы передаем параметр `tokenUrl`. Этот параметр содержит URL, который клиент (фронтенд, работающий в браузере пользователя) будет использовать для отправки `username` и `password`, чтобы получить токен.

{* ../../docs_src/security/tutorial001_an_py39.py hl[8] *}

/// tip | Подсказка

///

When we create an instance of the `OAuth2PasswordBearer` class we pass in the `tokenUrl` parameter. This parameter contains the URL that the client (the frontend running in the user's browser) will use to send the `username` and `password` in order to get a token.

{* ../../docs_src/security/tutorial001_an_py39.py hl[8] *}

/// tip

{* ../../docs_src/security/tutorial001_an_py39.py hl[8] *}

/// tip | Tipp

甚至可以说，它是适用于绝大多数用例的最佳方案，除非您是 OAuth2 的专家，知道为什么其它方案更合适。

本例中，**FastAPI** 还提供了构建工具。

///

创建 `OAuth2PasswordBearer` 的类实例时，要传递 `tokenUrl` 参数。该参数包含客户端（用户浏览器中运行的前端） 的 URL，用于发送 `username` 与 `password`，并获取令牌。

{* ../../docs_src/security/tutorial001.py hl[6] *}

/// tip | 提示

在此，`tokenUrl="token"` 指向的是暂未创建的相对 URL `token`。这个相对 URL 相当于 `./token`。

from typing import Union

from fastapi import Depends, FastAPI
from fastapi.security import OAuth2PasswordBearer
from pydantic import BaseModel

app = FastAPI()

oauth2_scheme = OAuth2PasswordBearer(tokenUrl="token")


class User(BaseModel):
    username: str
    email: Union[str, None] = None
    full_name: Union[str, None] = None
    disabled: Union[bool, None] = None


def fake_decode_token(token):
    return User(

        ] = None,
    ):
        if not scopes:
            scopes = {}
        flows = OAuthFlowsModel(
            password=cast(
                Any,
                {
                    "tokenUrl": tokenUrl,
                    "refreshUrl": refreshUrl,
                    "scopes": scopes,
                },
            )
        )
        super().__init__(
            flows=flows,

from fastapi.testclient import TestClient
from inline_snapshot import snapshot

oauth2_scheme = OAuth2AuthorizationCodeBearer(
    authorizationUrl="api/oauth/authorize",
    tokenUrl="/api/oauth/token",
    scopes={"read": "Read access", "write": "Write access"},
)


async def get_token(token: Annotated[str, Depends(oauth2_scheme)]) -> str:
    return token

from fastapi.security import OAuth2AuthorizationCodeBearer
from fastapi.testclient import TestClient
from inline_snapshot import snapshot

oauth2_scheme = OAuth2AuthorizationCodeBearer(
    authorizationUrl="authorize",
    tokenUrl="token",
    auto_error=True,
    scopes={"read": "Read access", "write": "Write access"},
)


async def get_token(token: Annotated[str, Depends(oauth2_scheme)]) -> str:
    return token

///

Quando criamos uma instância da classe `OAuth2PasswordBearer`, passamos o parâmetro `tokenUrl`. Esse parâmetro contém a URL que o client (o frontend rodando no navegador do usuário) usará para enviar o `username` e o `password` para obter um token.

{* ../../docs_src/security/tutorial001_an_py39.py hl[8] *}

/// tip | Dica