[19515] [INFO] Booting worker with pid: 19515
[19511] [INFO] Started server process [19511]
[19511] [INFO] Waiting for application startup.
[19511] [INFO] Application startup complete.
[19513] [INFO] Started server process [19513]
[19513] [INFO] Waiting for application startup.
[19513] [INFO] Application startup complete.
[19514] [INFO] Started server process [19514]
[19514] [INFO] Waiting for application startup.
[19514] [INFO] Application startup complete.

    **FastAPI** 只执行主应用中的事件处理器，不执行[子应用 - 挂载](sub-applications.md){.internal-link target=_blank}中的事件处理器。

## `startup` 事件

使用 `startup` 事件声明 `app` 启动前运行的函数：

```Python hl_lines="8"
{!../../../docs_src/events/tutorial001.py!}
```

本例中，`startup` 事件处理器函数为项目数据库（只是**字典**）提供了一些初始值。

**FastAPI** 支持多个事件处理器函数。

只有所有 `startup` 事件处理器运行完毕，**FastAPI** 应用才开始接收请求。

## `shutdown` 事件

使用 `shutdown` 事件声明 `app` 关闭时运行的函数：

### `startup`-Event

Um eine Funktion hinzuzufügen, die vor dem Start der Anwendung ausgeführt werden soll, deklarieren Sie diese mit dem Event `startup`:

```Python hl_lines="8"
{!../../../docs_src/events/tutorial001.py!}
```

In diesem Fall initialisiert die Eventhandler-Funktion `startup` die „Datenbank“ der Items (nur ein `dict`) mit einigen Werten.

  public void testStart_failed() {
    final Exception exception = new Exception("deliberate");
    TestService service =
        new TestService() {
          @Override
          protected void startUp() throws Exception {
            super.startUp();
            throw exception;
          }
        };
    assertEquals(0, service.startUpCalled);
    RuntimeException e =

[19515] [INFO] Booting worker with pid: 19515
[19511] [INFO] Started server process [19511]
[19511] [INFO] Waiting for application startup.
[19511] [INFO] Application startup complete.
[19513] [INFO] Started server process [19513]
[19513] [INFO] Waiting for application startup.
[19513] [INFO] Application startup complete.
[19514] [INFO] Started server process [19514]
[19514] [INFO] Waiting for application startup.
[19514] [INFO] Application startup complete.

    final CountDownLatch started = new CountDownLatch(1);
    FakeService service =
        new FakeService() {
          @Override
          protected void startUp() throws Exception {
            super.startUp();
            started.await();
          }
        };
    service.startAsync();
    service.stopAsync();
    started.countDown();
    service.awaitTerminated();

  public void testStart_failed() {
    final Exception exception = new Exception("deliberate");
    TestService service =
        new TestService() {
          @Override
          protected void startUp() throws Exception {
            super.startUp();
            throw exception;
          }
        };
    assertEquals(0, service.startUpCalled);
    RuntimeException e =

        }
      };

  /** Constructor for use by subclasses. */
  protected AbstractExecutionThreadService() {}

  /**
   * Start the service. This method is invoked on the execution thread.
   *
   * <p>By default this method does nothing.
   */
  protected void startUp() throws Exception {}

  /**
   * Run the service. This method is invoked on the execution thread. Implementations must respond

    final CountDownLatch started = new CountDownLatch(1);
    FakeService service =
        new FakeService() {
          @Override
          protected void startUp() throws Exception {
            super.startUp();
            started.await();
          }
        };
    service.startAsync();
    service.stopAsync();
    started.countDown();
    service.awaitTerminated();

<div class="termy">

```console
$ uvicorn main:app --reload

<span style="color: green;">INFO</span>:     Uvicorn running on http://127.0.0.1:8000 (Press CTRL+C to quit)
<span style="color: green;">INFO</span>:     Started reloader process [28720]
<span style="color: green;">INFO</span>:     Started server process [28722]