```JSON
{
  "detail": "Item not found"
}
```

/// tip | "豆知識"

`HTTPException`を発生させる際には、`str`だけでなく、JSONに変換できる任意の値を`detail`パラメータとして渡すことができます。

`dist`や`list`などを渡すことができます。

これらは **FastAPI** によって自動的に処理され、JSONに変換されます。

///

## カスタムヘッダーの追加

例えば、いくつかのタイプのセキュリティのために、HTTPエラーにカスタムヘッダを追加できると便利な状況がいくつかあります。

おそらくコードの中で直接使用する必要はないでしょう。

	globalObjectAPI = o
	globalObjLayerMutex.Unlock()
}

// objectAPIHandlers implements and provides http handlers for S3 API.
type objectAPIHandlers struct {
	ObjectAPI func() ObjectLayer
}

// getHost tries its best to return the request host.
// According to section 14.23 of RFC 2616 the Host header
// can include the port number if the default value of 80 is not used.
func getHost(r *http.Request) string {
	if r.URL.IsAbs() {

</p>
<p align="center">
<a href="https://github.com/fastapi/fastapi/actions?query=workflow%3ATest+event%3Apush+branch%3Amaster" target="_blank">
    <img src="https://github.com/fastapi/fastapi/workflows/Test/badge.svg?event=push&branch=master" alt="Test">
</a>
<a href="https://coverage-badge.samuelcolvin.workers.dev/redirect/fastapi/fastapi" target="_blank">
    <img src="https://coverage-badge.samuelcolvin.workers.dev/fastapi/fastapi.svg" alt="Coverage">

      first = false;
      if (o == collection) {
        sb.append("(this Collection)");
      } else {
        sb.append(o);
      }
    }
    return sb.append(']').toString();
  }

  /** Returns best-effort-sized StringBuilder based on the given collection size. */
  static StringBuilder newStringBuilderForCollection(int size) {
    checkNonnegative(size, "size");

   *     Queue<Integer>} but not a {@code Queue<Object>}).
   * @since 8.0
   */
  public static final class Builder<B> {
    /*
     * TODO(kevinb): when the dust settles, see if we still need this or can
     * just default to DEFAULT_CAPACITY.
     */
    private static final int UNSET_EXPECTED_SIZE = -1;

    private final Comparator<B> comparator;

By considering these concepts, you will be able to **evaluate and design** the best way to deploy **your own APIs**.

In the next chapters, I'll give you more **concrete recipes** to deploy FastAPI applications.

 *
 * <p>The tested methods and constructors are invoked -- each time with one parameter being null and
 * the rest not null -- and the test fails if no expected exception is thrown. {@code
 * NullPointerTester} uses best effort to pick non-null default values for many common JDK and Guava
 * types, and also for interfaces and public classes that have public parameter-less constructors.

</p>
<p align="center">
<a href="https://github.com/fastapi/fastapi/actions?query=workflow%3ATest+event%3Apush+branch%3Amaster" target="_blank">
    <img src="https://github.com/fastapi/fastapi/workflows/Test/badge.svg?event=push&branch=master" alt="Test">
</a>
<a href="https://coverage-badge.samuelcolvin.workers.dev/redirect/fastapi/fastapi" target="_blank">
    <img src="https://coverage-badge.samuelcolvin.workers.dev/fastapi/fastapi.svg" alt="Coverage">

    end
    subgraph azkaban-project[prisoner-of-azkaban project]
        azkaban(prisoner-of-azkaban) --> |requires| harry-3
    end
```

/// tip

It's very common in Python packages to try the best to **avoid breaking changes** in **new versions**, but it's better to be safe, and install newer versions intentionally and when you can run the tests to check everything is working correctly.

///

    * 也可以在现有 PR 中通过你使用的语言标签来筛选对应的 PR，举个例子，对于西班牙语，标签是 <a href="https://github.com/fastapi/fastapi/pulls?q=is%3Apr+is%3Aopen+sort%3Aupdated-desc+label%3Alang-es+label%3A%22awaiting+review%22" class="external-link" target="_blank">`lang-es`</a>。

* 请使用相同的 Python 示例，且只需翻译文档中的文本，不用修改其它东西。

* 请使用相同的图片、文件名以及链接地址，不用修改其它东西。