*
 *  * For synchronous calls made with [Call.execute], the exception is propagated to the caller.
 *
 *  * For asynchronous calls made with [Call.enqueue], an [IOException] is propagated to the caller
 *    indicating that the call was canceled. The interceptor's exception is delivered to the current
 *    thread's [uncaught exception handler][Thread.UncaughtExceptionHandler]. By default this

From this connection individual requests can be made.

Each handler, with optional subroutes can be registered with the manager using 
`Manager.RegisterXHandler(handlerID, handler, subroutes...)`.

A `Handler()` function provides an HTTP handler, which should be hooked up to the appropriate route on the server.

pkg log/slog, type Handler interface, Enabled(context.Context, Level) bool #56345
pkg log/slog, type Handler interface { Enabled, Handle, WithAttrs, WithGroup } #56345
pkg log/slog, type Handler interface, Handle(context.Context, Record) error #56345
pkg log/slog, type Handler interface, WithAttrs([]Attr) Handler #56345
pkg log/slog, type Handler interface, WithGroup(string) Handler #56345

{!../../../docs_src/custom_request_and_route/tutorial001.py!}
```

### 创建自定义 `GzipRoute` 类

接下来，创建使用 `GzipRequest` 的 `fastapi.routing.APIRoute  ` 的自定义子类。

此时，这个自定义子类会覆盖 `APIRoute.get_route_handler()`。

`APIRoute.get_route_handler()` 方法返回的是函数，并且返回的函数接收请求并返回响应。

本例用它根据原始请求创建 `GzipRequest`。

```Python hl_lines="18-26"
{!../../../docs_src/custom_request_and_route/tutorial001.py!}
```

!!! note "技术细节"

            activeLogger.level = Level.FINE
            handler.level = Level.FINE
            handler.formatter = MessageFormatter
            activeLogger.addHandler(handler)
          }

          if (sslDebug) {
            val activeLogger = getLogger("javax.net.ssl")

            activeLogger.level = Level.FINEST
            handler.level = Level.FINEST
            handler.formatter = MessageFormatter

            - post
            - delete
            - options
            - head
            - patch
            - trace
            - on_event
            - middleware

假设要触发的自定义异常叫作 `UnicornException`。

且需要 FastAPI 实现全局处理该异常。

此时，可以用 `@app.exception_handler()` 添加自定义异常控制器：

```Python hl_lines="5-7  13-18  24"
{!../../../docs_src/handling_errors/tutorial003.py!}

```

请求 `/unicorns/yolo` 时，路径操作会触发 `UnicornException`。

但该异常将会被 `unicorn_exception_handler` 处理。

接收到的错误信息清晰明了，HTTP 状态码为 `418`，JSON 内容如下：

```JSON

    /**
     * Creates a new event source and immediately returns it. Creating an event source initiates an
     * asynchronous process to connect the socket. Once that succeeds or fails, `listener` will be
     * notified. The caller must cancel the returned event source when it is no longer in use.
     */
    fun newEventSource(
      request: Request,
      listener: EventSourceListener,
    ): EventSource
  }

## Accessing the request body in an exception handler

!!! tip
    To solve this same problem, it's probably a lot easier to use the `body` in a custom handler for `RequestValidationError` ([Handling Errors](../tutorial/handling-errors.md#use-the-requestvalidationerror-body){.internal-link target=_blank}).

& 👆 💚 🍵 👉 ⚠ 🌐 ⏮️ FastAPI.

👆 💪 🚮 🛃 ⚠ 🐕‍🦺 ⏮️ `@app.exception_handler()`:

```Python hl_lines="5-7  13-18  24"
{!../../../docs_src/handling_errors/tutorial003.py!}
```

📥, 🚥 👆 📨 `/unicorns/yolo`, *➡ 🛠️* 🔜 `raise` `UnicornException`.

✋️ ⚫️ 🔜 🍵 `unicorn_exception_handler`.

, 👆 🔜 📨 🧹 ❌, ⏮️ 🇺🇸🔍 👔 📟 `418` & 🎻 🎚:

```JSON