/// info

The `OAuth2PasswordRequestForm` is not a special class for **FastAPI** as is `OAuth2PasswordBearer`.

`OAuth2PasswordBearer` makes **FastAPI** know that it is a security scheme. So it is added that way to OpenAPI.

But `OAuth2PasswordRequestForm` is just a class dependency that you could have written yourself, or you could have declared `Form` parameters directly.

import java.util.stream.Collectors;
import java.util.stream.Stream;

/**
 * NOTICE: this class is invoked via java command line, so we must NOT DEPEND ON ANY 3RD-PARTY LIBRARIES except JDK 11.
 *
 * Usage: java build-logic/cleanup/src/main/java/gradlebuild/cleanup/services/KillLeakingJavaProcesses.java
 */
public class KillLeakingJavaProcesses {
    enum ExecutionMode {
        /**

from fastapi.responses import JSONResponse
from fastapi.testclient import TestClient
from pydantic import BaseModel

app = FastAPI()


class JsonApiResponse(JSONResponse):
    media_type = "application/vnd.api+json"


class Error(BaseModel):
    status: str
    title: str


class JsonApiError(BaseModel):
    errors: list[Error]


@app.get(
    "/a/{id}",
    response_class=JsonApiResponse,

from typing import Union

from fastapi import FastAPI
from fastapi.responses import FileResponse
from pydantic import BaseModel


class Item(BaseModel):
    id: str
    value: str


responses = {
    404: {"description": "Item not found"},
    302: {"description": "The item was moved"},
    403: {"description": "Not enough privileges"},
}


app = FastAPI()


@app.get(
    "/items/{item_id}",

# Without aliases


@app.post("/required-list-str", operation_id="required_list_str")
async def read_required_list_str(p: Annotated[list[str], Form()]):
    return {"p": p}


class FormModelRequiredListStr(BaseModel):
    p: list[str]


@app.post("/model-required-list-str", operation_id="model_required_list_str")
def read_model_required_list_str(p: Annotated[FormModelRequiredListStr, Form()]):

运行示例并访问 <a href="http://127.0.0.1:8000/items/3" class="external-link" target="_blank">http://127.0.0.1:8000/items/3</a>，返回的响应如下：

```JSON
{"item_id":3}
```

/// check | 检查

注意，函数接收并返回的值是 `3`（ `int`），不是 `"3"`（`str`）。

**FastAPI** 通过类型声明自动<abbr title="将来自 HTTP 请求中的字符串转换为 Python 数据类型">**解析**请求中的数据</abbr>。

///

## 数据校验

import static org.junit.jupiter.api.Assertions.assertTrue;
import static org.mockito.Mockito.mock;
import static org.mockito.Mockito.when;

class ProjectSelectorTest {
    private final ProjectSelector sut = new ProjectSelector();
    private final MavenExecutionRequest mavenExecutionRequest = mock(MavenExecutionRequest.class);

    @Test
    void getBaseDirectoryFromRequestWhenDirectoryIsNullReturnNull() {

<div class="termy">

```console
$ pip install "fastapi[standard]"

---> 100%
```

</div>

/// note

When you install with `pip install "fastapi[standard]"` it comes with some default optional standard dependencies, including `fastapi-cloud-cli`, which allows you to deploy to <a href="https://fastapicloud.com" class="external-link" target="_blank">FastAPI Cloud</a>.

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(

app = FastAPI()


data = {
    "plumbus": {"description": "Freshly pickled plumbus", "owner": "Morty"},
    "portal-gun": {"description": "Gun to create portals", "owner": "Rick"},
}


class OwnerError(Exception):
    pass


def get_username():
    try:
        yield "Rick"
    except OwnerError as e:
        raise HTTPException(status_code=400, detail=f"Owner error: {e}")