) = apply {
      headers.add(name, value)
    }

    /** Removes all headers named [name] on this builder. */
    open fun removeHeader(name: String) =
      apply {
        headers.removeAll(name)
      }

    /** Removes all headers on this builder and adds [headers]. */
    open fun headers(headers: Headers) =
      apply {
        this.headers = headers.newBuilder()
      }

@pytest.mark.parametrize(
    "path",
    ["/optional-list-str", "/model-optional-list-str"],
)
def test_optional_list_str(path: str):
    client = TestClient(app)
    response = client.get(path, headers=[("p", "hello"), ("p", "world")])
    assert response.status_code == 200
    assert response.json() == {"p": ["hello", "world"]}


# =====================================================================================

    assert response.json() == {"detail": "Not authenticated"}
    assert response.headers["WWW-Authenticate"] == "Bearer"


def test_token(mod: ModuleType):
    client = TestClient(mod.app)
    access_token = get_access_token(scope="me", client=client)
    response = client.get(
        "/users/me", headers={"Authorization": f"Bearer {access_token}"}
    )
    assert response.status_code == 200, response.text

from fastapi import FastAPI
from fastapi.responses import JSONResponse

app = FastAPI()


@app.get("/headers/")
def get_headers():
    content = {"message": "Hello World"}
    headers = {"X-Cat-Dog": "alone in the world", "Content-Language": "en-US"}

/// warning

Before setting `convert_underscores` to `False`, bear in mind that some HTTP proxies and servers disallow the usage of headers with underscores.

///

## Duplicate headers { #duplicate-headers }

It is possible to receive duplicate headers. That means, the same header with multiple values.

You can define those cases using a list in the type declaration.

        return contentException;
    }

    /**
     * Sets the headers for the response.
     *
     * @param headers the headers to set.
     */
    public void setHeaders(final Map<String, List<String>> headers) {
        if (headers != null) {
            final Map<String, List<String>> map = new HashMap<>();
            headers.entrySet().stream().filter(e -> e.getKey() != null).forEach(

import org.codelibs.fess.crawler.exception.CrawlerSystemException;
import org.codelibs.fess.crawler.exception.MimeTypeException;
import org.codelibs.fess.crawler.helper.MimeTypeHelper;

/**
 * MimeTypeHelperImpl is a helper class that detects the MIME type of a given input stream or filename.
 * It uses the Apache Tika library to detect the MIME type.
 *
 * <p>
 * This class provides methods to:
 * </p>

import org.codelibs.fess.app.web.api.admin.FessApiAdminAction;
import org.codelibs.fess.app.web.api.admin.searchlist.ApiAdminSearchlistAction;
import org.codelibs.fess.helper.CrawlingConfigHelper;
import org.codelibs.fess.helper.CrawlingInfoHelper;
import org.codelibs.fess.helper.LanguageHelper;
import org.codelibs.fess.opensearch.client.SearchEngineClient;
import org.codelibs.fess.thumbnail.ThumbnailManager;
import org.codelibs.fess.util.ComponentUtil;

**FastAPI** 将从请求中接收到的 **headers** 中**提取**出**每个字段**的数据，并提供您定义的 Pydantic 模型。

## 查看文档

您可以在文档 UI 的 `/docs` 中查看所需的 headers：

<div class="screenshot">
<img src="/img/tutorial/header-param-models/image01.png">
</div>

## 禁止额外的 Headers

在某些特殊使用情况下（可能并不常见），您可能希望**限制**您想要接收的 headers。

您可以使用 Pydantic 的模型配置来禁止（ `forbid` ）任何额外（ `extra` ）字段：

    filename: Annotated[Optional[str], Doc("The original file name.")]
    size: Annotated[Optional[int], Doc("The size of the file in bytes.")]
    headers: Annotated[Headers, Doc("The headers of the request.")]
    content_type: Annotated[
        Optional[str], Doc("The content type of the request, from the headers.")
    ]

    async def write(
        self,
        data: Annotated[
            bytes,
            Doc(
                """