# 响应头

## 使用 `Response` 参数

你可以在你的*路径操作函数*中声明一个`Response`类型的参数（就像你可以为cookies做的那样）。

然后你可以在这个*临时*响应对象中设置头部。
```Python hl_lines="1  7-8"
{!../../../docs_src/response_headers/tutorial002.py!}
```

然后你可以像平常一样返回任何你需要的对象（例如一个`dict`或者一个数据库模型）。如果你声明了一个`response_model`，它仍然会被用来过滤和转换你返回的对象。

**FastAPI**将使用这个临时响应来提取头部（也包括cookies和状态码），并将它们放入包含你返回的值的最终响应中，该响应由任何`response_model`过滤。

你也可以在依赖项中声明`Response`参数，并在其中设置头部（和cookies）。

## 直接返回 `Response`

    And as the `Response` can be used frequently to set headers and cookies, **FastAPI** also provides it at `fastapi.Response`.

## Custom Headers

Keep in mind that custom proprietary headers can be added <a href="https://developer.mozilla.org/en-US/docs/Web/HTTP/Headers" class="external-link" target="_blank">using the 'X-' prefix</a>.

    Y como la `Response` puede ser usada frecuentemente para configurar headers y cookies, **FastAPI** también la provee en `fastapi.Response`.

## Headers Personalizados

Ten en cuenta que se pueden añadir headers propietarios personalizados <a href="https://developer.mozilla.org/en-US/docs/Web/HTTP/Headers" class="external-link" target="_blank">usando el prefijo 'X-'</a>.

    Und da die `Response` häufig zum Setzen von Headern und Cookies verwendet wird, stellt **FastAPI** diese auch unter `fastapi.Response` bereit.

## Benutzerdefinierte Header

Beachten Sie, dass benutzerdefinierte proprietäre Header <a href="https://developer.mozilla.org/en-US/docs/Web/HTTP/Headers" class="external-link" target="_blank">mittels des Präfix 'X-'</a> hinzugefügt werden können.

## 🛃 🎚

✔️ 🤯 👈 🛃 © 🎚 💪 🚮 <a href="https://developer.mozilla.org/en-US/docs/Web/HTTP/Headers" class="external-link" target="_blank">⚙️ '✖-' 🔡</a>.

    val expected = Instant.ofEpochMilli(0L)
    val headers =
      Headers.Builder()
        .add("Test-Instant", expected)
        .build()
    assertThat(headers["Test-Instant"]).isEqualTo("Thu, 01 Jan 1970 00:00:00 GMT")
    assertThat(headers.getInstant("Test-Instant")).isEqualTo(expected)
  }

  @Test fun setDate() {
    val expected = Date(1000)
    val headers =
      Headers.Builder()
        .add("testDate", Date(0L))

    val headers1 =
      Headers.Builder()
        .add("Connection", "close")
        .add("Transfer-Encoding", "chunked")
        .build()
    val headers2 =
      Headers.Builder()
        .add("Connection", "keep-alive")
        .add("Transfer-Encoding", "chunked")
        .build()
    assertThat(headers2).isNotEqualTo(headers1)
    assertThat(headers2.hashCode()).isNotEqualTo(headers1.hashCode().toLong())
  }

  @JvmName("-deprecated_getHeaders")
  @Deprecated(
    message = "moved to var",
    replaceWith = ReplaceWith(expression = "headers"),
    level = DeprecationLevel.ERROR,
  )
  fun getHeaders(): Headers = headers

  fun setHeaders(headers: Headers) = apply { this.headers = headers }

  @JvmName("-deprecated_getTrailers")
  @Deprecated(
    message = "moved to var",

import java.util.Date
import okhttp3.Headers.Companion.headersOf
import org.junit.jupiter.api.Test

class HeadersKotlinTest {
  @Test fun getOperator() {
    val headers = headersOf("a", "b", "c", "d")
    assertThat(headers["a"]).isEqualTo("b")
    assertThat(headers["c"]).isEqualTo("d")
    assertThat(headers["e"]).isNull()
  }

  @Test fun iteratorOperator() {
    val headers = headersOf("a", "b", "c", "d")

    }

    FLAGS[FLAG_END_HEADERS] = "END_HEADERS" // Same as END_PUSH_PROMISE.
    FLAGS[FLAG_PRIORITY] = "PRIORITY" // Same as FLAG_COMPRESSED.
    FLAGS[FLAG_END_HEADERS or FLAG_PRIORITY] = "END_HEADERS|PRIORITY" // Only valid on HEADERS.
    val frameFlags = intArrayOf(FLAG_END_HEADERS, FLAG_PRIORITY, FLAG_END_HEADERS or FLAG_PRIORITY)

    for (frameFlag in frameFlags) {