「中介軟體」是一個函式，在任何特定的*路徑操作*處理之前先處理每個**請求**；在回傳之前，也會處理每個**回應**。

- 它會攔截進到應用程式的每個**請求**。
- 然後可以對該**請求**做一些處理或執行所需的程式碼。
- 接著把**請求**傳遞給應用程式的其餘部分（某個*路徑操作*）處理。
- 之後再接收應用程式（某個*路徑操作*）所產生的**回應**。
- 可以對該**回應**做一些處理或執行所需的程式碼。
- 然後回傳**回應**。

/// note | 技術細節

如果你有使用帶有 `yield` 的相依性，其釋放階段的程式碼會在中介軟體之後執行。

若有背景工作（在[背景工作](background-tasks.md)一節會介紹，你稍後會看到），它們會在所有中介軟體之後執行。

///

## 建立中介軟體 { #create-a-middleware }

要建立中介軟體，將裝飾器 `@app.middleware("http")` 加在函式上方。

* Look only at the `Score` column and ignore `Error`. Instead take countermeasures to keep `Error` low / variance explainable.

## Disassembling

NOTE: Linux only. Sorry Mac and Windows.

Disassembling is fun! Maybe not always useful, but always fun! Generally, you'll want to install `perf` and FCML's `hsdis`.

                    .println("Tool purpose is to configure password management on developer workstations.");
            context.terminal
                    .writer()
                    .println(
                            "Note: Generated configuration can be moved/copied to headless environments, if configured as such.");
            return EncryptInvoker.BAD_OPERATION;
        }

        return doExecute(context);
    }

    Client->>Client: Process Item 1
    App->>Client: Send Item 2
    App->>App: Produce Item 3
    Client->>Client: Process Item 2
    App->>Client: Send Item 3
    Client->>Client: Process Item 3
    Note over App: Keeps producing...
    Note over Client: Keeps consuming...
```

データを送り続ける無限ストリームにすることもできます。

## JSON Lines { #json-lines }

このような場合、1 行に 1 つの JSON オブジェクトを送る「**JSON Lines**」形式を使うのが一般的です。

   * Note that when {@code containsKey(key)} is false, this returns an empty collection, not {@code
   * null}.
   *
   * <p>Changes to the returned collection will update the underlying multimap, and vice versa.
   */
  Collection<V> get(@ParametricNullness K key);

  /**
   * Returns a view collection of all <i>distinct</i> keys contained in this multimap. Note that the

    }

    /**
     * Test that delayForWaitingNewUrl doesn't throw exceptions
     * This tests the improved error handling with proper logging
     * Note: This is a basic smoke test since full integration testing
     * requires ComponentUtil and other dependencies
     */
    @Test
    public void test_delayForWaitingNewUrl_noExceptions() {

import org.codelibs.core.net.URLUtil;
import org.codelibs.core.nio.ChannelUtil;
import org.codelibs.core.timer.TimeoutManager;

/**
 * Utility class for handling {@link File}.
 * <p>
 * <strong>SECURITY NOTE:</strong> When accepting file paths from untrusted sources,
 * always validate them using {@link #isPathSafe(Path, Path)} to prevent path traversal attacks.

   * response body is [closed][ResponseBody]. The recipient of the callback may consume the response
   * body on another thread.
   *
   * Note that transport-layer success (receiving a HTTP response code, headers and body) does not
   * necessarily indicate application-layer success: `response` may still indicate an unhappy HTTP
   * response code like 404 or 500.
   */

   * method. The returned lists implement {@link RandomAccess}, whether or not the input list does.
   *
   * <p><b>Note:</b> The current implementation eagerly allocates storage for {@code size} elements.
   * As a consequence, passing values like {@code Integer.MAX_VALUE} can lead to {@link
   * OutOfMemoryError}.
   *
   * <p><b>Note:</b> if {@code iterable} is a {@link List}, use {@link Lists#partition(List, int)}
   * instead.
   *

이렇게 호출한 결과는 파이썬 표준인 [`json.dumps()`](https://docs.python.org/3/library/json.html#json.dumps)로 인코딩할 수 있습니다.

JSON 형식(문자열)의 데이터가 들어있는 큰 `str`을 반환하지 않습니다. JSON과 모두 호환되는 값과 하위 값이 있는 파이썬 표준 데이터 구조(예: `dict`)를 반환합니다.

/// note | 참고

`jsonable_encoder`는 실제로 **FastAPI**에서 내부적으로 데이터를 변환하는 데 사용하지만, 다른 많은 시나리오에서도 유용합니다.