* the given character set encoder.
   *
   * @param reader input source
   * @param encoder character set encoder used for encoding chars to bytes
   * @param bufferSize size of internal input and output buffers
   * @throws IllegalArgumentException if bufferSize is non-positive
   */
  ReaderInputStream(Reader reader, CharsetEncoder encoder, int bufferSize) {
    this.reader = checkNotNull(reader);

Si vous ne déclarez pas de modèle de réponse, FastAPI utilisera le `jsonable_encoder` expliqué dans [Encodeur compatible JSON](../tutorial/encoder.md) et le placera dans une `JSONResponse`.

import org.junit.jupiter.params.provider.ArgumentsSource

/**
 * Tests for round-tripping headers through hpack.
 *
 * TODO: update hpack-test-case with the output of our encoder.
 * This test will hide complementary bugs in the encoder and decoder,
 * We should test that the encoder is producing responses that are
 */
class HpackRoundTripTest : HpackDecodeTestBase() {
  internal class StoriesTestProvider : SimpleProvider() {

## Base64 vs fichiers { #base64-vs-files }

Envisagez d'abord d'utiliser [Fichiers de requête](../tutorial/request-files.md) pour téléverser des données binaires et [Réponse personnalisée - FileResponse](./custom-response.md#fileresponse--fileresponse-) pour envoyer des données binaires, plutôt que de les encoder dans du JSON.

## Daten in etwas JSON-kompatibles konvertieren { #convert-any-data-to-json-compatible }

Um Daten in etwas JSON-kompatibles zu konvertieren, lesen Sie die Dokumentation unter [Tutorial – JSON-kompatibler Encoder](../tutorial/encoder.md).

## OpenAPI-Metadaten – Dokumentation { #openapi-metadata-docs }

from datetime import datetime

from fastapi import FastAPI
from fastapi.encoders import jsonable_encoder
from fastapi.responses import JSONResponse
from pydantic import BaseModel


class Item(BaseModel):
    title: str
    timestamp: datetime
    description: str | None = None


app = FastAPI()


@app.put("/items/{id}")
def update_item(id: str, item: Item):
    json_compatible_item_data = jsonable_encoder(item)

	}
	*eDays = ExpirationDays(numDays)
	return nil
}

// MarshalXML encodes number of days to expire if it is non-zero and
// encodes empty string otherwise
func (eDays ExpirationDays) MarshalXML(e *xml.Encoder, startElement xml.StartElement) error {
	if eDays == 0 {
		return nil
	}
	return e.EncodeElement(int(eDays), startElement)
}

// ExpirationDate is a embedded type containing time.Time to unmarshal

from fastapi import FastAPI, Request
from fastapi.encoders import jsonable_encoder
from fastapi.exceptions import RequestValidationError
from fastapi.responses import JSONResponse
from pydantic import BaseModel

app = FastAPI()


@app.exception_handler(RequestValidationError)
async def validation_exception_handler(request: Request, exc: RequestValidationError):
    return JSONResponse(
        status_code=422,

If you don't declare a response model, FastAPI will use the `jsonable_encoder` explained in [JSON Compatible Encoder](../tutorial/encoder.md) and put it in a `JSONResponse`.

You could also create a `JSONResponse` directly and return it.

/// tip

Если вы не объявите модель ответа, FastAPI использует `jsonable_encoder`, как описано в [JSON кодировщик](../tutorial/encoder.md), и поместит результат в `JSONResponse`.

Также вы можете создать `JSONResponse` напрямую и вернуть его.

/// tip | Подсказка