{* ../../docs_src/body/tutorial001_py310.py hl[5:9] *}

就和宣告查詢參數時一樣，當模型屬性有預設值時，它就不是必填；否則就是必填。使用 `None` 可使其成為選填。

例如，上述模型對應的 JSON「`object`」（或 Python `dict`）如下：

```JSON
{
    "name": "Foo",
    "description": "An optional description",
    "price": 45.2,
    "tax": 3.5
}
```

...由於 `description` 與 `tax` 是選填（預設為 `None`），以下這個 JSON「`object`」也有效：

```JSON
{
    "name": "Foo",
    "price": 45.2
}
```

/// warning | 警告

你可以在一个*路径操作*中声明多个 `File` 和 `Form` 参数，但不能同时声明希望以 JSON 接收的 `Body` 字段，因为此时请求体会使用 `multipart/form-data` 编码，而不是 `application/json`。

这不是 **FastAPI** 的限制，而是 HTTP 协议的一部分。

///

## 可选文件上传 { #optional-file-upload }

你可以通过使用标准类型注解并将 `None` 作为默认值的方式将一个文件参数设为可选:

{* ../../docs_src/request_files/tutorial001_02_an_py310.py hl[9,17] *}

## 带有额外元数据的 `UploadFile` { #uploadfile-with-additional-metadata }

To get a connection to a specific server, use `Manager.Connection(host)` to get a connection to the specified host.
From this connection individual requests can be made.

Each handler, with optional subroutes can be registered with the manager using
`Manager.RegisterXHandler(handlerID, handler, subroutes...)`.

A `Handler()` function provides an HTTP handler, which should be hooked up to the appropriate route on the server.

import org.codelibs.fess.dict.DictionaryException;
import org.codelibs.fess.dict.DictionaryFile;
import org.codelibs.fess.util.ComponentUtil;
import org.codelibs.fess.util.KuromojiCSVUtil;
import org.dbflute.optional.OptionalEntity;

/**
 * A dictionary file for Kuromoji.
 */
public class KuromojiFile extends DictionaryFile<KuromojiItem> {
    private static final String KUROMOJI = "kuromoji";

 * accuracy, use {@code System.nanoTime()} directly instead.
 *
 * <p>Basic usage:
 *
 * {@snippet :
 * Stopwatch stopwatch = Stopwatch.createStarted();
 * doSomething();
 * stopwatch.stop(); // optional
 *
 * Duration duration = stopwatch.elapsed();
 *
 * log.info("time: " + stopwatch); // formatted string like "12.3 ms"
 * }
 *

        SMBUtil.writeInt4(status, hdr, 8);
        // Write Command = SMB2_IOCTL (0x000B) at offset 12
        SMBUtil.writeInt2(0x000B, hdr, 12);
        // Mark as server response to be realistic (optional)
        SMBUtil.writeInt4(0x00000001, hdr, 16); // Flags = SMB2_FLAGS_SERVER_TO_REDIR
        return hdr;
    }

    // Helper: build SMB2 IOCTL response body (without header) with structureSize=49

## Why distributed MinIO?

MinIO in distributed mode can help you setup a highly-available storage system with a single object storage deployment. With distributed MinIO, you can optimally use storage devices, irrespective of their location in a network.

### Data protection

    * **WebSockets**
    * pruebas extremadamente fáciles basadas en HTTPX y `pytest`
    * **CORS**
    * **Sesiones de Cookies**
    * ...y más.

### Despliega tu app (opcional) { #deploy-your-app-optional }

Opcionalmente puedes desplegar tu app de FastAPI en [FastAPI Cloud](https://fastapicloud.com), ve y únete a la lista de espera si no lo has hecho. 🚀

    * **WebSockets**
    * testes extremamente fáceis baseados em HTTPX e `pytest`
    * **CORS**
    * **Cookie Sessions**
    * ...e mais.

### Implemente sua aplicação (opcional) { #deploy-your-app-optional }

Você pode opcionalmente implantar sua aplicação FastAPI na [FastAPI Cloud](https://fastapicloud.com), vá e entre na lista de espera se ainda não o fez. 🚀

import org.jspecify.annotations.Nullable;

/**
 * CompactLinkedHashMap is an implementation of a Map with insertion or LRU iteration order,
 * maintained with a doubly linked list through the entries. All optional operations (put and
 * remove) are supported. Null keys and values are supported.
 *
 * <p>{@code containsKey(k)}, {@code put(k, v)} and {@code remove(k)} are all (expected and