Tudo construído como ferramentas e componentes reutilizáveis que são fáceis de integrar com seus sistemas, armazenamento de dados, banco de dados relacionais e não-relacionais etc.

### Injeção de dependência { #dependency-injection }

FastAPI inclui um sistema de <abbr title='também conhecido como "components", "resources", "services", "providers"'><strong>injeção de dependência</strong></abbr> extremamente fácil de usar, mas extremamente poderoso.

    public SpnegoAuthenticator() {
        // do nothing
    }

    /**
     * Initializes the SPNEGO authenticator and registers it with the SSO manager.
     * This method is called automatically after dependency injection is complete.
     */
    @PostConstruct
    public void init() {
        if (logger.isDebugEnabled()) {
            logger.debug("Initializing {}", this.getClass().getSimpleName());
        }

    * 標頭（Header）
    * 查詢參數
    * Cookies，等等。

加上来自 Starlette（包括 **session cookie**）的所有安全特性。

所有的這些都是可重複使用的工具和套件，可以輕鬆與你的系統、資料儲存（Data Stores）、關聯式資料庫（RDBMS）以及非關聯式資料庫（NoSQL）等等整合。


### 依賴注入（Dependency Injection）

FastAPI 有一個使用簡單，但是非常強大的<abbr title='也叫做 "components", "resources", "services", "providers"'><strong>依賴注入</strong></abbr>系統。

* 依賴項甚至可以有自己的依賴，從而形成一個層級或**依賴圖**的結構。
* 所有**自動化處理**都由框架完成。

   * of this queue less the current {@code size} of this queue.
   *
   * <p>Note that you cannot always tell if an attempt to insert an element will succeed by
   * inspecting {@code remainingCapacity} because it may be the case that another thread is about to
   * insert or remove an element.
   */
  @CanIgnoreReturnValue
  @Override
  public int remainingCapacity() {

  @Test fun ipv6AddressMalformed() {
    val cookie = parse("http://[::1]/".toHttpUrl(), "a=b; domain=::2::2")
    assertThat(cookie!!.domain).isEqualTo("::1")
  }

  /**
   * These public suffixes were selected by inspecting the publicsuffix.org list. It's possible they
   * may change in the future. If this test begins to fail, please double check they are still
   * present in the public suffix list.
   */
  @Test fun domainIsPublicSuffix() {

     * ヘッダー
     * クエリパラメータ
     * クッキー、等

さらに、Starletteのすべてのセキュリティ機能も含みます（**セッションCookie**を含む）。

これらは、システム、データストア、リレーショナルデータベース、NoSQLデータベースなどと簡単に統合できる再利用可能なツールとコンポーネントとして構築されています。

### 依存性の注入（Dependency Injection）

FastAPIには非常に使いやすく、非常に強力な<abbr title='also known as "components", "resources", "services", "providers"'><strong>依存性の注入</strong></abbr>システムを備えています。

* 依存関係でさえも依存関係を持つことができ、階層または **依存関係の"グラフ"** を作成することができます。

## 0.61.0

### Features

* Add support for injecting `HTTPConnection` (as `Request` and `WebSocket`). Useful for sharing app state in dependencies. PR [#1827](https://github.com/tiangolo/fastapi/pull/1827) by [@nsidnev](https://github.com/nsidnev).

     * Initializes a new instance with default settings.
     */
    public IndexUpdater() {
        super();
    }

    /**
     * Initializes the IndexUpdater after dependency injection.
     * Sets up the ingest factory if available in the component container.
     */
    @PostConstruct
    public void init() {
        if (logger.isDebugEnabled()) {

/**
 * A manager for monitoring and controlling a set of {@linkplain Service services}. This class
 * provides methods for {@linkplain #startAsync() starting}, {@linkplain #stopAsync() stopping} and
 * {@linkplain #servicesByState inspecting} a collection of {@linkplain Service services}.
 * Additionally, users can monitor state transitions with the {@linkplain Listener listener}
 * mechanism.
 *

/**
 * A manager for monitoring and controlling a set of {@linkplain Service services}. This class
 * provides methods for {@linkplain #startAsync() starting}, {@linkplain #stopAsync() stopping} and
 * {@linkplain #servicesByState inspecting} a collection of {@linkplain Service services}.
 * Additionally, users can monitor state transitions with the {@linkplain Listener listener}
 * mechanism.
 *