}

    @Override
    protected void doStop() {
      fail();
    }
  }

  private static class RunFailingService extends AbstractService {
    @Override
    protected void doStart() {
      notifyStarted();
      notifyFailed(EXCEPTION);
    }

    @Override
    protected void doStop() {
      fail();
    }
  }

    }

    @Override
    protected void doStop() {
      fail();
    }
  }

  private static class RunFailingService extends AbstractService {
    @Override
    protected void doStart() {
      notifyStarted();
      notifyFailed(EXCEPTION);
    }

    @Override
    protected void doStop() {
      fail();
    }
  }

        fakeRemote.file + "/.git"
        gradleRunner(workingRemoteGit, "wrapper").build()

        execute("git init", workingRemoteGit)
        execute('git config user.email "******@****.***"', workingRemoteGit)
        execute('git config user.name "Build tool"', workingRemoteGit)
        execute("git add .", workingRemoteGit)
        execute('git commit -m"Initial"', workingRemoteGit)

        // Execute and expect IOException
        try {
            webApiFilter.doFilter(request, response, chain);
            fail("Expected IOException");
        } catch (IOException e) {
            assertEquals("Test IOException", e.getMessage());
        } catch (ServletException e) {
            fail("Unexpected ServletException: " + e.getMessage());
        }
    }

在路徑操作函式內，使用 `.add_task()` 將任務函式加入背景任務物件：

{* ../../docs_src/background_tasks/tutorial001_py310.py hl[14] *}

`.add_task()` 的引數包括：

* 要在背景執行的任務函式（`write_notification`）。
* 依序傳給任務函式的位置引數（`email`）。
* 要傳給任務函式的關鍵字引數（`message="some notification"`）。

## 相依性注入 { #dependency-injection }

在相依性注入系統中也可使用 `BackgroundTasks`。你可以在多個層級宣告 `BackgroundTasks` 型別的參數：路徑操作函式、相依項（dependable）、次級相依項等。

services are setup with [DNS SRV Records](https://ldap.com/dns-srv-records-for-ldap/) for high-availability of the directory service. To use this to find LDAP servers to connect to, an LDAP client makes a DNS SRV record request to the DNS service on a domain that looks like `_service._proto.example.com`. For LDAP the `proto` value is always `tcp`, and `service` is usually `ldap` or `ldaps`.

To enable MinIO to use the SRV records, specify the `srv_record_name` config parameter (or equivalently...

      value = value.trim()

      result.add(
        Cookie
          .Builder()
          .name(name)
          .value(value)
          .domain(url.host)
          .build(),
      )
      pos = pairEnd + 1
    }
    return result
  }

如果客户尝试发送一些**额外的 headers**，他们将收到**错误**响应。

例如，如果客户端尝试发送一个值为 `plumbus` 的 `tool` header，客户端将收到一个**错误**响应，告知他们 header 参数 `tool` 是不允许的：

```json
{
    "detail": [
        {
            "type": "extra_forbidden",
            "loc": ["header", "tool"],
            "msg": "Extra inputs are not permitted",
            "input": "plumbus",
        }
    ]
}
```

app = FastAPI()


class Item(BaseModel):
    name: str
    price: float


class ResponseMessage(BaseModel):
    message: str


class User(BaseModel):
    username: str
    email: str


@app.post("/items/", response_model=ResponseMessage, tags=["items"])
async def create_item(item: Item):
    return {"message": "Item received"}

You can define this *startup* and *shutdown* logic using the `lifespan` parameter of the `FastAPI` app, and a "context manager" (I'll show you what that is in a second).

Let's start with an example and then see it in detail.

We create an async function `lifespan()` with `yield` like this:

{* ../../docs_src/events/tutorial003_py310.py hl[16,19] *}