## Use `CORSMiddleware` { #use-corsmiddleware }

You can configure it in your **FastAPI** application using the `CORSMiddleware`.

* Import `CORSMiddleware`.
* Create a list of allowed origins (as strings).
* Add it as a "middleware" to your **FastAPI** application.

You can also specify whether your backend allows:

* Credentials (Authorization headers, Cookies, etc).

    e: IOException,
    call: RealCall,
    chain: Interceptor.Chain,
    userRequest: Request,
  ): Boolean {
    val requestSendStarted = e !is ConnectionShutdownException

    // The application layer has forbidden retries.
    if (!chain.retryOnConnectionFailure) return false

    // We can't send the request body again.
    if (requestSendStarted && requestIsOneShot(e, userRequest)) return false

				dst[typ+"-"+name+"."+prof.Extension()] = buf
			}
		}
	}
	return dst, nil
}

func setDefaultProfilerRates() {
	runtime.MemProfileRate = 128 << 10 // 512KB -> 128K - Must be constant throughout application lifetime.
	runtime.SetMutexProfileFraction(0) // Disable until needed
	runtime.SetBlockProfileRate(0)     // Disable until needed
}

worker_processes  auto;

error_log  /var/log/nginx/error.log warn;
pid        /var/run/nginx.pid;

events {
    worker_connections  4096;
}

http {
    include       /etc/nginx/mime.types;
    default_type  application/octet-stream;

    log_format  main  '$remote_addr - $remote_user [$time_local] "$request" '
                      '$status $body_bytes_sent "$http_referer" '
                      '"$http_user_agent" "$http_x_forwarded_for"';

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);

    Note over Client: Keeps consuming...
```

它甚至可以是無限串流，你可以一直持續傳送資料。

## JSON Lines { #json-lines }

在這些情況下，常見做法是傳送「**JSON Lines**」，這是一種每一行各包含一個 JSON 物件的格式。

回應的 content type 會是 `application/jsonl`（而不是 `application/json`），而本體內容會像這樣：

```json
{"name": "Plumbus", "description": "A multi-purpose household device."}
{"name": "Portal Gun", "description": "A portal opening device."}

INFO:     Uvicorn running on http://127.0.0.1:8000 (Press CTRL+C to quit)
INFO:     Started reloader process [2248755] using WatchFiles
INFO:     Started server process [2248757]
INFO:     Waiting for application startup.
INFO:     Application startup complete.
```

</div>

<details markdown="1">
<summary>About the command <code>fastapi dev</code>...</summary>

     <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>

출력되는 줄들 중에는 아래와 같은 내용이 있습니다:

```hl_lines="4"
INFO:     Uvicorn running on http://127.0.0.1:8000 (Press CTRL+C to quit)

                        "responses": {
                            "200": {
                                "description": "Successful Response",
                                "content": {"application/json": {"schema": {}}},
                            }
                        },
                        "security": [{"HTTPBearer": []}],
                    }
                }
            },

// of the objects in a bucket. You can use the request parameters as selection
// criteria to return a subset of the objects in a bucket.
//
// NOTE: It is recommended that this API to be used for application development.
// MinIO continues to support ListObjectsV1 and V2 for supporting legacy tools.
func (api objectAPIHandlers) ListObjectsV2MHandler(w http.ResponseWriter, r *http.Request) {
	ctx := newContext(r, w, "ListObjectsV2M")