本例中，客户端用 `ID` 请求的 `item` 不存在时，触发状态码为 `404` 的异常：

{* ../../docs_src/handling_errors/tutorial001.py hl[11] *}

### 响应结果

请求为 `http://example.com/items/foo`（`item_id` 为 `「foo」`）时，客户端会接收到 HTTP 状态码 - 200 及如下 JSON 响应结果：

```JSON
{
  "item": "The Foo Wrestlers"
}

```

但如果客户端请求 `http://example.com/items/bar`（`item_id` `「bar」` 不存在时），则会接收到 HTTP 状态码 - 404（「未找到」错误）及如下 JSON 响应结果：

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

   | the build process. Profiles provided in the settings.xml are intended to provide local machine-
   | specific paths and repository locations which allow the build to work in the local environment.
   |
   | For example, if you have an integration testing plugin - like cactus - that needs to know where
   | your Tomcat instance is installed, you can provide a variable here such that the variable is

Em seguida, você executaria o servidor passando as configurações como variáveis de ambiente, por exemplo, você poderia definir `ADMIN_EMAIL` e `APP_NAME` com:

<div class="termy">

```console
$ ADMIN_EMAIL="deadpool@example.com" APP_NAME="ChimichangApp" fastapi run main.py

<span style="color: green;">INFO</span>:     Uvicorn running on http://127.0.0.1:8000 (Press CTRL+C to quit)
```

</div>

/// tip | Dica

 *   <li>{@link DataService} - The service for managing access results.</li>
 * </ul>
 *
 * <p>Each parameter is stored in a ThreadLocal variable to ensure thread safety.</p>
 *
 * <p>Usage example:</p>
 * <pre>
 * {@code
 * UrlQueue<?> urlQueue = CrawlingParameterUtil.getUrlQueue();
 * CrawlingParameterUtil.setUrlQueue(newUrlQueue);
 *
 * CrawlerContext context = CrawlingParameterUtil.getCrawlerContext();

 *
 * We provide implementations of collections that forward all method calls to a delegate collection
 * by default. Subclasses can override one or more methods to implement the decorator pattern. For
 * an example, see {@link ForwardingCollection}.
 *
 * <h2>Other</h2>
 *
 * <ul>
 *   <li>{@link EvictingQueue}
 *   <li>{@link Interner}, {@link Interners}
 *   <li>{@link MapMaker}
 *   <li>{@link MinMaxPriorityQueue}

{* ../../docs_src/advanced_middleware/tutorial002_py39.py hl[2,6:8] *}

Die folgenden Argumente werden unterstützt:

* `allowed_hosts` – Eine Liste von Domain-Namen, die als Hostnamen zulässig sein sollten. Wildcard-Domains wie `*.example.com` werden unterstützt, um Subdomains zu matchen. Um jeden Hostnamen zu erlauben, verwenden Sie entweder `allowed_hosts=["*"]` oder lassen Sie diese Middleware weg.

El `TestClient` está basado en <a href="https://www.python-httpx.org" class="external-link" target="_blank">HTTPX</a>, y afortunadamente, podemos usarlo directamente para probar la API.

## Ejemplo { #example }

 * </ul>
 *
 * <p>These features are all optional; caches can be created using all or none of them. By default,
 * cache instances created by {@code CacheBuilder} will not perform any type of eviction.
 *
 * <p>Usage example:
 *
 * {@snippet :
 * LoadingCache<Key, Graph> graphs = CacheBuilder.newBuilder()
 *     .maximumSize(10000)
 *     .expireAfterWrite(Duration.ofMinutes(10))
 *     .removalListener(MY_LISTENER)
 *     .build(

 *
 * @author Jared Levy
 */
@GwtCompatible
@NullMarked
public abstract class TestStringCollectionGenerator implements TestCollectionGenerator<String> {
  @Override
  public SampleElements<String> samples() {
    return new Strings();
  }

  @Override
  public Collection<String> create(Object... elements) {
    String[] array = new String[elements.length];
    int i = 0;
    for (Object e : elements) {

 *
 * @author Jared Levy
 */
@GwtCompatible
@NullMarked
public abstract class TestStringQueueGenerator implements TestQueueGenerator<String> {
  @Override
  public SampleElements<String> samples() {
    return new Strings();
  }

  @Override
  public Queue<String> create(Object... elements) {
    String[] array = new String[elements.length];
    int i = 0;
    for (Object e : elements) {