`CORSMiddleware` отвечает на два типа HTTP-запросов...

### CORS-запросы с предварительной проверкой

Это любые `OPTIONS` запросы с заголовками `Origin` и `Access-Control-Request-Method`.

В этом случае middleware перехватит входящий запрос и отправит соответствующие CORS-заголовки в ответе, а также ответ `200` или `400` в информационных целях.

### Простые запросы

# Header-Parameter

So wie `Query`-, `Path`-, und `Cookie`-Parameter können Sie auch <abbr title='Header – Kopfzeilen, Header, Header-Felder: Schlüssel-Wert-Metadaten, die vom Client beim Request, und vom Server bei der Response gesendet werden'>Header</abbr>-Parameter definieren.

## `Header` importieren

Importieren Sie zuerst `Header`:

//// tab | Python 3.10+

```Python hl_lines="3"
{!> ../../docs_src/header_params/tutorial001_an_py310.py!}
```

    /**
     * @param tc
     *            context to use
     * @param auth
     *            credentials
     * @param doSigning
     *            whether signing is requested
     */
    public NtlmContext ( CIFSContext tc, NtlmPasswordAuthenticator auth, boolean doSigning ) {
        this.transportContext = tc;
        this.auth = auth;

- Fixed bug in kubectl rollout history where only the latest revision was displayed when a specific revision was requested and an output format was specified ([#111093](https:...

        }
        if (elements.length > 0) {
          multiset1.add(elements[0]);
        }
        if (elements.length > 1) {
          /*
           * When a test requests a multiset with duplicates, our plan of
           * "add an extra item 0 to A and an extra item 1 to B" really means
           * "add an extra item 0 to A and B," which isn't what we want.
           */

* Even dependencies can have dependencies, creating a hierarchy or **"graph" of dependencies**.
* All **automatically handled** by the framework.
* All the dependencies can require data from requests and **augment the path operation** constraints and automatic documentation.
* **Automatic validation** even for *path operation* parameters defined in dependencies.

                     "intervalFactor": 2,
                     "legendFormat": "{{cluster}} - {{namespace}} - {{host}} - {{method}}\n"
                  }
               ],
               "title": "Failed Requests",
               "type": "timeseries"
            }
         ],
         "title": "Kubernetes Client",
         "type": "row"
      },
      {
         "collapsed": true,
         "gridPos": {

    String INDEXER_WEBFS_MAX_DOCUMENT_REQUEST_SIZE = "indexer.webfs.max.document.request.size";

    /** The key of the configuration. e.g. 10000 */
    String INDEXER_DATA_MAX_DOCUMENT_CACHE_SIZE = "indexer.data.max.document.cache.size";

    /** The key of the configuration. e.g. 1048576 */
    String INDEXER_DATA_MAX_DOCUMENT_REQUEST_SIZE = "indexer.data.max.document.request.size";

    /** The key of the configuration. e.g. 100 */

        });
        try (InputStream inputStream = form.kuromojiFile.getInputStream()) {
            file.update(inputStream);
        } catch (final IOException e) {
            logger.warn("Failed to process a request.", e);
            throwValidationErrorApi(messages -> messages.addErrorsFailedToUploadProtwordsFile(GLOBAL));
        }
        return asJson(new ApiResult.ApiResponse().status(ApiResult.Status.OK).result());
    }

En utilisant seulement `BackgroundTasks` (et non `BackgroundTask`), il est possible de l'utiliser en tant que paramètre de *fonction de chemin* et de laisser **FastAPI** gérer le reste pour vous, comme en utilisant l'objet `Request` directement.

Il est tout de même possible d'utiliser `BackgroundTask` seul dans **FastAPI**, mais dans ce cas il faut créer l'objet dans le code et renvoyer une `Response` Starlette l'incluant.