import okhttp3.MediaType;
import okhttp3.OkHttpClient;
import okhttp3.Request;
import okhttp3.RequestBody;
import okhttp3.Response;

public class PostExample {
  public static final MediaType JSON = MediaType.get("application/json; charset=utf-8");

  final OkHttpClient client = new OkHttpClient();

  String post(String url, String json) throws IOException {
    RequestBody body = RequestBody.create(json, JSON);

 * specific language governing permissions and limitations
 * under the License.
 */
package org.apache.maven.project;

import org.apache.maven.artifact.Artifact;

/**
 * This exception is thrown if an application attempts to attach
 * two of the same artifacts to a single project.
 *
 * TODO Make this a checked exception, and modify the API of MavenProjectHelper.

但如果你直接返回 `Response`，返回数据不会自动转换，也不会自动生成文档（例如，在 HTTP 头 `Content-Type` 中包含特定的「媒体类型」作为生成的 OpenAPI 的一部分）。

你还可以在 *路径操作装饰器* 中声明你想用的 `Response`。

你从 *路径操作函数* 中返回的内容将被放在该 `Response` 中。

并且如果该 `Response` 有一个 JSON 媒体类型（`application/json`），比如使用 `JSONResponse` 或者 `UJSONResponse` 的时候，返回的数据将使用你在路径操作装饰器中声明的任何 Pydantic 的 `response_model` 自动转换（和过滤）。

/// note | 说明

如果你使用不带有任何媒体类型的响应类，FastAPI 认为你的响应没有任何内容，所以不会在生成的OpenAPI文档中记录响应格式。

///

<font color="#4E9A06">INFO</font>:     Started server process [<font color="#06989A">2265873</font>]
<font color="#4E9A06">INFO</font>:     Waiting for application startup.
<font color="#4E9A06">INFO</font>:     Application startup complete.
</pre>
```

</div>

**強烈建議**你編寫或複製程式碼、進行修改並在本地端運行。

在編輯器中使用它，才能真正體會到 FastAPI 的好處，可以看到你只需編寫少量程式碼，以及所有的型別檢查、自動補齊等功能。

---

## 安裝 FastAPI

     <span style="background-color:#007166"><font color="#D3D7CF"> INFO </font></span>  Waiting for application startup.
     <span style="background-color:#007166"><font color="#D3D7CF"> INFO </font></span>  Application startup complete.
```

</div>

In the output, there's a line with something like:

```hl_lines="4"

  @Throws(IOException::class)
  abstract fun writeTo(sink: BufferedSink)

  /**
   * A duplex request body is special in how it is **transmitted** on the network and
   * in the **API contract** between OkHttp and the application.
   *
   * This method returns false unless it is overridden by a subclass.
   *
   * ### Duplex Transmission
   *
   * With regular HTTP calls the request always completes sending before the response may begin

**FastAPI** will make sure to read that data from the right place instead of JSON.

/// note | Technical Details

Data from forms is normally encoded using the "media type" `application/x-www-form-urlencoded` when it doesn't include files.

But when the form includes files, it is encoded as `multipart/form-data`. If you use `File`, **FastAPI** will know it has to get the files from the correct part of the body.

     <span style="background-color:#007166"><font color="#D3D7CF"> INFO </font></span>  Waiting for application startup.
     <span style="background-color:#007166"><font color="#D3D7CF"> INFO </font></span>  Application startup complete.

**FastAPI** se certificará de ler esses dados do lugar certo, ao invés de JSON.

/// note | Detalhes Técnicos

Dados de formulários normalmente são codificados usando o "media type" `application/x-www-form-urlencoded` quando não incluem arquivos.

                "get": {
                    "responses": {
                        "200": {
                            "description": "Successful Response",
                            "content": {"application/json": {"schema": {}}},
                        }
                    },
                    "summary": "Read Items",
                    "operationId": "read_items_items__get",