當你建立一個 **FastAPI** 的路徑操作 (path operation) 時，通常可以從中回傳任何資料：`dict`、`list`、Pydantic 模型、資料庫模型等。

如果你宣告了 [回應模型](../tutorial/response-model.md)，FastAPI 會用 Pydantic 將資料序列化為 JSON。

如果你沒有宣告回應模型，FastAPI 會使用在[JSON 相容編碼器](../tutorial/encoder.md)中說明的 `jsonable_encoder`，並把它放進 `JSONResponse`。

但你也可以直接從路徑操作回傳 `JSONResponse`。

/// tip

通常使用 [回應模型](../tutorial/response-model.md) 會有更好的效能，因為那樣會在 Rust 端使用 Pydantic 來序列化資料，而不是直接回傳 `JSONResponse`。

///

* Partager des connexions à la base de données.
* Imposer la sécurité, l’authentification, des exigences de rôles, etc.
* Et bien d’autres choses ...

Tout cela, en minimisant la répétition de code.

## Premiers pas { #first-steps }

Voyons un exemple très simple. Il sera tellement simple qu’il n’est pas très utile, pour l’instant.

        // CharUtil.isUrlChar does NOT include { }, so they get percent-encoded
        String result = DocumentUtil.encodeUrl("http://example.com/{id}");
        assertEquals("http://example.com/%7Bid%7D", result);
    }

    @Test
    public void test_encodeUrl_unicodeChars() {
        // Non-ASCII characters are percent-encoded; encoding depends on request context

// Copyright 2018 The Go Authors. All rights reserved.
// Use of this source code is governed by a BSD-style
// license that can be found in the LICENSE file.

#include "../../../../../runtime/textflag.h"

TEXT asmtest(SB),DUPOK|NOSPLIT,$0
	// Instructions that were encoded with BYTE sequences.
	// Included to simplify validation of CL that fixed that.
	MOVQ (AX), M0  // 0f6f00
	MOVQ M0, 8(SP) // 0f7f442408
	MOVQ 8(SP), M0 // 0f6f442408

# Note that we must use nightly here as these are used in nightly jobs
# For release jobs, we will pin these on the release branch
keras-nightly ~= 3.12.0.dev
tb-nightly ~= 2.20.0.a
# For new protobuf, if V.x.y is gencode version, then runtime version U must be
# V <= U <= V+1
# More info at https://protobuf.dev/support/cross-version-runtime-guarantee/
protobuf >= 5.28.0, < 7.0
# Test dependencies

  static class MaxCodePoint {
    final int value;

    /**
     * Convert the input string to a code point. Accepts regular decimal numerals, hex strings, and
     * some symbolic names meaningful to humans.
     */
    private static int decode(String userFriendly) {
      try {
        return Integer.decode(userFriendly);
      } catch (NumberFormatException ignored) {

     * @param bufferIndex the starting offset in the buffer
     * @param len the length of data to decode
     * @throws IOException if an I/O error occurs during decoding
     */
    public SecurityDescriptor(final byte[] buffer, final int bufferIndex, final int len) throws IOException {
        this.decode(buffer, bufferIndex, len);
    }

    /**
     * Gets the type flags of this security descriptor.
     *

        return stream(getRoles()).get(stream -> stream.map(this::decode).toArray(n -> new String[n]));
    }

    @Override
    public String[] getGroupNames() {
        return stream(getGroups()).get(stream -> stream.map(this::decode).toArray(n -> new String[n]));
    }

    private String decode(final String value) {
        return new String(Base64.getDecoder().decode(value), Constants.CHARSET_UTF_8);
    }

    @Override

If you have a Pydantic model in your test and you want to send its data to the application during testing, you can use the `jsonable_encoder` described in [JSON Compatible Encoder](encoder.md).

///

## Run it { #run-it }

After that, you just need to install `pytest`.

[응답 모델](../tutorial/response-model.md)을 선언하면 FastAPI는 Pydantic을 사용해 데이터를 JSON으로 직렬화합니다.

응답 모델을 선언하지 않으면, FastAPI는 [JSON 호환 가능 인코더](../tutorial/encoder.md)에 설명된 `jsonable_encoder`를 사용해 데이터를 변환하고 이를 `JSONResponse`에 넣습니다.

또한 `JSONResponse`를 직접 생성해 반환할 수도 있습니다.

/// tip | 팁