* </ul>
 * <p>
 * <strong>Usage Example:</strong>
 * </p>
 * <pre>
 * CachedCipher cipher = new CachedCipher();
 * cipher.setKey("mySecretKey");
 *
 * // Encrypt text
 * String encrypted = cipher.encryptText("Hello World");
 *
 * // Decrypt text
 * String decrypted = cipher.decryptText(encrypted);
 *
 * // For AES encryption
 * CachedCipher aesCipher = new CachedCipher();
 * aesCipher.setAlgorithm("AES");

### Проверьте { #check-it }

Откройте браузер по адресу: <a href="http://127.0.0.1:8000" class="external-link" target="_blank">http://127.0.0.1:8000</a>.

Вы увидите JSON-ответ вида:

```JSON
{"message": "Hello World"}
```

### Интерактивная документация API { #interactive-api-docs }

Теперь перейдите по адресу: <a href="http://127.0.0.1:8000/docs" class="external-link" target="_blank">http://127.0.0.1:8000/docs</a>.

For example, if you have a function:

```Python
@lru_cache
def say_hi(name: str, salutation: str = "Ms."):
    return f"Hello {salutation} {name}"
```

your program could execute like this:

```mermaid
sequenceDiagram

participant code as Code
participant function as say_hi()
participant execute as Execute function

```

该行显示了你的应用在本机所提供服务的 URL 地址。

### 查看

打开浏览器访问 <a href="http://127.0.0.1:8000" class="external-link" target="_blank">http://127.0.0.1:8000</a>。

你将看到如下的 JSON 响应：

```JSON
{"message": "Hello World"}
```

### 交互式 API 文档

跳转到 <a href="http://127.0.0.1:8000/docs" class="external-link" target="_blank">http://127.0.0.1:8000/docs</a>。

					n := 0
					var latency int64
					managers := grid.Managers
					hosts := grid.Hosts
					req := testRequest{
						Num:    rng.Int(),
						String: "hello",
					}
					for pb.Next() {
						// Pick a random manager.
						src, dst := rng.Intn(len(managers)), rng.Intn(len(managers))
						if src == dst {
							dst = (dst + 1) % len(managers)
						}

				Mode:     0666,
			},
		},
	},
	{
		// created in windows XP file manager.
		Name: "winxp.zip",
		File: []ZipTestFile{
			{
				Name:     "hello",
				Content:  []byte("world \r\n"),
				Modified: time.Date(2011, 12, 8, 10, 4, 24, 0, time.UTC),
				Mode:     0666,
			},
			{
				Name:     "dir/bar",
				Content:  []byte("foo \r\n"),

Cuando un request contiene datos inválidos, **FastAPI** lanza internamente un `RequestValidationError`.

Y también incluye un manejador de excepciones predeterminado para ello.

Para sobrescribirlo, importa el `RequestValidationError` y úsalo con `@app.exception_handler(RequestValidationError)` para decorar el manejador de excepciones.

////

## Blocos de código { #code-blocks }

//// tab | Teste

Um exemplo de código Bash...

```bash
# Imprimir uma saudação ao universo
echo "Hello universe"
```

...e um exemplo de código de console...

```console
$ <font color="#4E9A06">fastapi</font> run <u style="text-decoration-style:solid">main.py</u>

### Confira { #check-it }

Abra o seu navegador em <a href="http://127.0.0.1:8000" class="external-link" target="_blank">http://127.0.0.1:8000</a>.

Você verá essa resposta em JSON:

```JSON
{"message": "Hello World"}
```

### Documentação Interativa de APIs { #interactive-api-docs }

Agora vá para <a href="http://127.0.0.1:8000/docs" class="external-link" target="_blank">http://127.0.0.1:8000/docs</a>.

### Compruébalo { #check-it }

Abre tu navegador en <a href="http://127.0.0.1:8000" class="external-link" target="_blank">http://127.0.0.1:8000</a>.

Verás el response JSON como:

```JSON
{"message": "Hello World"}
```

### Documentación interactiva de la API { #interactive-api-docs }

Ahora ve a <a href="http://127.0.0.1:8000/docs" class="external-link" target="_blank">http://127.0.0.1:8000/docs</a>.