# Header-Parameter

So wie `Query`-, `Path`-, und `Cookie`-Parameter können Sie auch <abbr title='Header – Kopfzeilen, Header, Header-Felder: Schlüssel-Wert-Metadaten, die vom Client beim Request, und vom Server bei der Response gesendet werden'>Header</abbr>-Parameter definieren.

## `Header` importieren

Importieren Sie zuerst `Header`:

=== "Python 3.10+"

    ```Python hl_lines="3"
    {!> ../../../docs_src/header_params/tutorial001_an_py310.py!}

 * limitations under the License.
 */
package okhttp3.internal.http2

import okio.ByteString
import okio.ByteString.Companion.encodeUtf8

/** HTTP header: the name is an ASCII string, but the value can be UTF-8. */
data class Header(
  /** Name in case-insensitive ASCII encoding. */
  @JvmField val name: ByteString,
  /** Value in UTF-8 encoding. */
  @JvmField val value: ByteString,
) {

    open fun url(url: URL) = url(url.toString().toHttpUrl())

    /**
     * Sets the header named [name] to [value]. If this request already has any headers
     * with that name, they are all replaced.
     */
    open fun header(
      name: String,
      value: String,
    ) = commonHeader(name, value)

    /**
     * Adds a header with [name] and [value]. Prefer this method for multiply-valued
     * headers like "Cookie".

    ```

!!! info
    Der zusätzliche Header `WWW-Authenticate` mit dem Wert `Bearer`, den wir hier zurückgeben, ist ebenfalls Teil der Spezifikation.

    Jeder HTTP-(Fehler-)Statuscode 401 „UNAUTHORIZED“ soll auch einen `WWW-Authenticate`-Header zurückgeben.

    Im Fall von Bearer-Tokens (in unserem Fall) sollte der Wert dieses Headers `Bearer` lauten.

)

filegroup(
    name = "pywrap_headers_monitoring_reader",
    srcs = [
        "c_api_experimental_reader.h",
        "tfe_monitoring_reader_internal.h",
    ],
    visibility = ["//tensorflow:__subpackages__"],
)

filegroup(
    name = "headers_monitoring_reader",
    srcs = [
        "c_api_experimental_reader.h",
    ],
    visibility = ["//tensorflow:__subpackages__"],
)

        .build()
    val request =
      originalRequest.newBuilder()
        .header("Upgrade", "websocket")
        .header("Connection", "Upgrade")
        .header("Sec-WebSocket-Key", key)
        .header("Sec-WebSocket-Version", "13")
        .header("Sec-WebSocket-Extensions", "permessage-deflate")
        .build()
    call = RealCall(webSocketClient, request, forWebSocket = true)
    call!!.enqueue(

| `contact` | `dict` | Die Kontaktinformationen für die verfügbar gemachte API. Kann mehrere Felder enthalten. <details><summary><code>contact</code>-Felder</summary><table><thead><tr><th>Parameter</th><th>Typ</th><th>Beschreibung</th></tr></thead><tbody><tr><td><code>name</code></td><td><code>str</code></td><td>Der identifizierende Name der Kontaktperson/Organisation.</td...

        "custom-foo",
        "custom-header",
        "custom-bar",
        "custom-header",
        "custom-baz",
        "custom-header",
      )
    bytesIn.writeByte(0x40) // Literal indexed
    bytesIn.writeByte(0x0a) // Literal name (len = 10)
    bytesIn.writeUtf8("custom-foo")
    bytesIn.writeByte(0x0d) // Literal value (len = 13)
    bytesIn.writeUtf8("custom-header")
    bytesIn.writeByte(0x40) // Literal indexed

    assertThat(request.header("Host")).isNull()
    assertThat(request.header("Accept-Encoding")).isNull()

    // No extra headers in the application's response.
    val response = client.newCall(request).execute()
    assertThat(request.header("Content-Encoding")).isNull()
    assertThat(response.body.string()).isEqualTo("abcabcabc")
  }

  @Test

  }

  @Test fun http2HeadersListDropsForbiddenHeadersHttp2() {
    val request =
      Request.Builder()
        .url("http://square.com/")
        .header("Connection", "upgrade")
        .header("Upgrade", "websocket")
        .header("Host", "square.com")
        .header("TE", "gzip")
        .build()
    val expected =
      headerEntries(
        ":method",
        "GET",
        ":path",
        "/",