*       be overridden.
 * </ul>
 *
 * <h3>Example</h3>
 *
 * {@snippet :
 * return Converter.from(
 *     Integer::toHexString,
 *     s -> parseUnsignedInt(s, 16));
 * }
 *
 * <p>An alternative using a subclass:
 *
 * {@snippet :
 * return new Converter<Integer, String>() {
 *   @Override
 *   protected String doForward(Integer i) {
 *     return Integer.toHexString(i);
 *   }
 *

///

FastAPI 现在会：

- 对数据进行**校验**，确保最大长度为 50 个字符
- 当数据无效时向客户端展示**清晰的错误**
- 在 OpenAPI 模式的*路径操作*中**记录**该参数（因此会出现在**自动文档 UI** 中）

## 另一种（旧的）方式：把 `Query` 作为默认值 { #alternative-old-query-as-the-default-value }

早期版本的 FastAPI（<dfn title="早于 2023-03">0.95.0</dfn> 之前）要求你把 `Query` 作为参数的默认值，而不是放在 `Annotated` 里。你很可能会在别处看到这种写法，所以我也给你解释一下。

/// tip | 提示

   *
   * <p>Prefer {@link Double#BYTES} instead.
   *
   * @since 10.0
   */
  public static final int BYTES = Double.BYTES;

  /**
   * Returns a hash code for {@code value}; obsolete alternative to {@link Double#hashCode(double)}.
   *
   * @param value a primitive {@code double} value
   * @return a hash code for the value
   */
  @InlineMe(replacement = "Double.hashCode(value)")

    inappropriate.

 *  New: `HttpUrl.get(String)` is an alternative to `HttpUrl.parse(String)` that throws an exception
    when the URL is malformed instead of returning null. Use this to avoid checking for null in
    situations where the input is known to be well-formed. We've also added `MediaType.get(String)`
    which is an exception-throwing alternative to `MediaType.parse(String)`.

  }

  /**
   * The supplied multimap will be mutated and an unmodifiable instance used in its stead. If the
   * multimap does not support null keys or values, alternatives may be specified for tests
   * involving nulls.
   */
  private static void checkUnmodifiableMultimap(
      Multimap<@Nullable String, @Nullable Integer> multimap,
      boolean permitsDuplicates,

你将看到自动生成的交互式 API 文档（由 [Swagger UI](https://github.com/swagger-api/swagger-ui) 提供）：

![Swagger UI](https://fastapi.tiangolo.com/img/index/index-01-swagger-ui-simple.png)

## 备选 API 文档 { #alternative-api-docs }

你还可以访问 [http://192.168.99.100/redoc](http://192.168.99.100/redoc) 或 [http://127.0.0.1/redoc](http://127.0.0.1/redoc)（或其他等价地址，取决于你的 Docker 主机）。

你将看到备选的自动文档（由 [ReDoc](https://github.com/Rebilly/ReDoc) 提供）：

	// Second, if ContentErr==nil, the content should match Content.
	// If content is large, an alternative to setting Content is to set File,
	// which names a file in the testdata/ directory containing the
	// uncompressed expected content.
	// If content is very large, an alternative to setting Content or File
	// is to set Size, which will then be checked against the header-reported size

    Corresponding Source from a network server at no charge.

    c) Convey individual copies of the object code with a copy of the
    written offer to provide the Corresponding Source.  This
    alternative is allowed only occasionally and noncommercially, and
    only if you received the object code with such an offer, in accord
    with subsection 6b.

    d) Convey the object code by offering access from a designated

            });

    List<Object> result = doConcurrentGet(cache, "bar", count, startSignal);

    assertThat(callCount.get()).isEqualTo(1);
    for (int i = 0; i < count; i++) {
      // doConcurrentGet alternates between calling getUnchecked and calling get, but an unchecked
      // exception thrown by the loader is always wrapped as an UncheckedExecutionException.

* Fix typo. PR [#1326](https://github.com/tiangolo/fastapi/pull/1326) by [@chenl](https://github.com/chenl).
* Add translation to Portuguese for [Alternatives, Inspiration and Comparisons - Alternativas, Inspiração e Comparações](https://fastapi.tiangolo.com/pt/alternatives/). PR [#1325](https://github.com/tiangolo/fastapi/pull/1325) by [@Serrones](https://github.com/Serrones).