![Swagger UI interaction](https://fastapi.tiangolo.com/img/index/index-03-swagger-02.png)

* Alternative API documentation with [**ReDoc**](https://github.com/Rebilly/ReDoc).

![ReDoc](https://fastapi.tiangolo.com/img/index/index-06-redoc-02.png)

### Just Modern Python { #just-modern-python }

![Interação Swagger UI](https://fastapi.tiangolo.com/img/index/index-03-swagger-02.png)

* Documentação alternativa da API com [**ReDoc**](https://github.com/Rebilly/ReDoc).

![ReDoc](https://fastapi.tiangolo.com/img/index/index-06-redoc-02.png)

### Apenas Python moderno { #just-modern-python }

Other HTTP libraries exist that fill that gap allowing extensive customisation including potentially
invalid requests.

Example Limitations

* Does not allow GET with a body.
* Cache is not an interface with alternative implementations.

Get a URL
---------

This program downloads a URL and prints its contents as a string. [Full source][get_example].

```java
OkHttpClient client = new OkHttpClient();

 *
 * <ul>
 *   <li>The raw {@code long} values returned by {@code nanoTime} are meaningless and unsafe to use
 *       in any other way than how {@code Stopwatch} uses them.
 *   <li>An alternative source of nanosecond ticks can be substituted, for example for testing or
 *       performance reasons, without affecting most of your code.
 * </ul>
 *

  }

  /**
   * Indicates that the load and store operations will be very efficient because of use of VarHandle
   * or Unsafe. May be useful for calling code to fall back on an alternative implementation that is
   * slower than those implementations but faster than the pure-Java mask-and-shift.
   */
  static boolean usingFastPath() {
    return byteArray.usesFastPath();
  }

  /**

自動対話型 API ドキュメントが表示されます（[Swagger UI](https://github.com/swagger-api/swagger-ui) が提供しています）。

![Swagger UI](https://fastapi.tiangolo.com/img/index/index-01-swagger-ui-simple.png)

### 代替 API ドキュメント { #alternative-api-docs }

次に、[http://127.0.0.1:8000/redoc](http://127.0.0.1:8000/redoc) にアクセスします。

代替の自動ドキュメントが表示されます（[ReDoc](https://github.com/Rebilly/ReDoc) が提供しています）。

            assertThat(expected).hasMessageThat().isEqualTo(expectedMessage);
          }
        }
      }
    },
    /*
     * This one comes last to work around b/367716565. (One *possible* alternative would be to not
     * declare any methods in this enum, converting assertFailsToDecode into a static method that is
     * implemented with a `switch`. I haven't tested that.)
     */

你將看到自動的互動式 API 文件（由 [Swagger UI](https://github.com/swagger-api/swagger-ui) 提供）：

![Swagger UI](https://fastapi.tiangolo.com/img/index/index-01-swagger-ui-simple.png)

### 替代 API 文件 { #alternative-api-docs }

現在，前往 [http://127.0.0.1:8000/redoc](http://127.0.0.1:8000/redoc)。

你將看到另一種自動文件（由 [ReDoc](https://github.com/Rebilly/ReDoc) 提供）：

![ReDoc](https://fastapi.tiangolo.com/img/index/index-02-redoc-simple.png)

자동 대화형 API 문서를 볼 수 있습니다 ([Swagger UI](https://github.com/swagger-api/swagger-ui) 제공):

![Swagger UI](https://fastapi.tiangolo.com/img/index/index-01-swagger-ui-simple.png)

### 대안 API 문서 { #alternative-api-docs }

그리고 이제 [http://127.0.0.1:8000/redoc](http://127.0.0.1:8000/redoc)로 가봅시다.

다른 자동 문서를 볼 수 있습니다([ReDoc](https://github.com/Rebilly/ReDoc) 제공):

但在我们上面的例子里，我们并不是直接使用，而是传递给 FastAPI 来供其使用。

`FastAPI` 的 `lifespan` 参数接受一个**异步上下文管理器**，所以我们可以把我们新定义的异步上下文管理器 `lifespan` 传给它。

{* ../../docs_src/events/tutorial003_py310.py hl[22] *}

## 替代事件（弃用） { #alternative-events-deprecated }

/// warning | 警告

配置**启动**和**关闭**的推荐方法是使用 `FastAPI` 应用的 `lifespan` 参数，如前所示。如果你提供了一个 `lifespan` 参数，启动（`startup`）和关闭（`shutdown`）事件处理器将不再生效。要么使用 `lifespan`，要么配置所有事件，两者不能共用。

你可以跳过这一部分。

///