S’il y avait des tâches d’arrière-plan (présentées dans la section [Tâches d’arrière-plan](background-tasks.md), que vous verrez plus tard), elles s’exécuteront après tous les middlewares.

///

## Créer un middleware { #create-a-middleware }

Pour créer un middleware, utilisez le décorateur `@app.middleware("http")` au-dessus d’une fonction.

La fonction de middleware reçoit :

* La `request`.

Wenn es Hintergrundtasks gab (dies wird später im [Hintergrundtasks](background-tasks.md)-Abschnitt behandelt), werden sie *nach* allen Middlewares ausgeführt.

///

## Eine Middleware erstellen { #create-a-middleware }

Um eine Middleware zu erstellen, verwenden Sie den Dekorator `@app.middleware("http")` über einer Funktion.

Die Middleware-Funktion erhält:

* Den `request`.

func (u Err) Hint(m string, args ...any) Err {
	e := u.Clone()
	e.hint = fmt.Sprintf(m, args...)
	return e
}

// ErrFn function wrapper
type ErrFn func(err error) Err

// Create a UI error generator, this is needed to simplify
// the update of the detailed error message in several places
// in MinIO code
func newErrFn(msg, action, hint string) ErrFn {
	return func(err error) Err {
		u := Err{

import jcifs.internal.smb2.rdma.RdmaChannelInfo;
import jcifs.internal.util.SMBUtil;

/**
 * SMB2 Write request message.
 *
 * This command is used to write data to a file that has been
 * previously opened with a Create request.
 *
 * @author mbechler
 */
public class Smb2WriteRequest extends ServerMessageBlock2Request<Smb2WriteResponse> implements RequestWithFileId {

    /**

        assertEquals(tree, unwrapped);
        // Test unwrapping to a non-assignable type should fail
        assertThrows(ClassCastException.class, () -> {
            // Create a mock class that extends SmbTree but is not assignable from SmbTreeImpl
            class CustomSmbTree extends SmbTreeImpl {
                CustomSmbTree() {
                    super(session, "SHARE", "A:");
                }

 *   <li>file system errors: permissions</li>
 * </ul>
 *
 * TODO carlos: all these possible has*Exceptions and get*Exceptions methods make the clients too
 *       complex requiring a long list of checks, need to create a parent/interface/encapsulation
 *       for the types of exceptions
 */
@Deprecated
public class ArtifactResolutionResult {
    private static final String LS = System.lineSeparator();

Then, when you type that username and password, the browser sends them in the header automatically.

## Simple HTTP Basic Auth { #simple-http-basic-auth }

* Import `HTTPBasic` and `HTTPBasicCredentials`.
* Create a "`security` scheme" using `HTTPBasic`.
* Use that `security` with a dependency in your *path operation*.
* It returns an object of type `HTTPBasicCredentials`:
    * It contains the `username` and `password` sent.

## Use `CORSMiddleware` { #use-corsmiddleware }

You can configure it in your **FastAPI** application using the `CORSMiddleware`.

* Import `CORSMiddleware`.
* Create a list of allowed origins (as strings).
* Add it as a "middleware" to your **FastAPI** application.

You can also specify whether your backend allows:

* Credentials (Authorization headers, Cookies, etc).

		respRecorder := xhttp.NewResponseRecorder(w)

		// Setup a http request body recorder
		reqRecorder := &xhttp.RequestRecorder{Reader: r.Body}
		r.Body = reqRecorder

		// Create tracing data structure and associate it to the request context
		tc := mcontext.TraceCtxt{
			AmzReqID:         w.Header().Get(xhttp.AmzRequestID),
			RequestRecorder:  reqRecorder,
			ResponseRecorder: respRecorder,
		}

// Should only be called if a failure occurred.
func (o listPathOptions) checkMetacacheState(ctx context.Context, rpc *peerRESTClient) error {
	// We operate on a copy...
	o.Create = false
	c, err := rpc.GetMetacacheListing(ctx, o)
	if err != nil {
		return err
	}
	cache := *c

	if cache.status == scanStateNone || cache.fileNotFound {
		return errFileNotFound
	}