@JvmField
    val EMPTY: RequestBody = ByteString.EMPTY.toRequestBody()

    /**
     * Returns a new request body that transmits this string. If [contentType] is non-null and lacks
     * a charset, this will use UTF-8.
     */
    @JvmStatic
    @JvmName("create")
    fun String.toRequestBody(contentType: MediaType? = null): RequestBody {

      )
    call.execute().use { response ->
      val requestBody = (call.request().body as AsyncRequestBody?)!!.takeSink()
      requestBody.writeUtf8("request A\n")
      requestBody.flush()
      val responseBody = response.body.source()
      assertThat(responseBody.readUtf8Line())
        .isEqualTo("response B")
      requestBody.writeUtf8("request C\n")
      requestBody.flush()
      assertThat(responseBody.readUtf8Line())

    assertOnFileDescriptor { fd ->
      val requestBody = fd.toRequestBody()

      assertThat(requestBody.contentLength()).isEqualTo(-1L)
      assertThat(requestBody.isOneShot()).isEqualTo(true)
    }
  }

  @Test
  fun testFileDescriptorRead() {
    assertOnFileDescriptor(content = "Hello") { fd ->
      val requestBody = fd.toRequestBody()

      val buffer = Buffer()
      requestBody.writeTo(buffer)

  public void run() throws Exception {
    Map<String, String> requestBody = new LinkedHashMap<>();
    requestBody.put("longUrl", "https://publicobject.com/2014/12/04/html-formatting-javadocs/");
    RequestBody jsonRequestBody = RequestBody.create(
        mapJsonAdapter.toJson(requestBody), MEDIA_TYPE_JSON);
    Request request = new Request.Builder()

	public static synthetic fun create$default (Lokhttp3/RequestBody$Companion;Ljava/lang/String;Lokhttp3/MediaType;ILjava/lang/Object;)Lokhttp3/RequestBody;
	public static synthetic fun create$default (Lokhttp3/RequestBody$Companion;Lokhttp3/MediaType;[BIIILjava/lang/Object;)Lokhttp3/RequestBody;
	public static synthetic fun create$default (Lokhttp3/RequestBody$Companion;Lokio/ByteString;Lokhttp3/MediaType;ILjava/lang/Object;)Lokhttp3/RequestBody;

Einige Anwendungsfälle sind:

* Konvertieren von Nicht-JSON-Requestbodys nach JSON (z. B. <a href="https://msgpack.org/index.html" class="external-link" target="_blank">`msgpack`</a>).
* Dekomprimierung gzip-komprimierter Requestbodys.
* Automatisches Loggen aller Requestbodys.

## Handhaben von benutzerdefinierten Requestbody-Kodierungen { #handling-custom-request-body-encodings }

import okhttp3.MediaType.Companion.toMediaType
import okhttp3.OkHttpClient
import okhttp3.Request
import okhttp3.RequestBody
import okio.BufferedSink

class PostStreaming {
  private val client = OkHttpClient()

  fun run() {
    val requestBody =
      object : RequestBody() {
        override fun contentType() = MEDIA_TYPE_MARKDOWN

        override fun writeTo(sink: BufferedSink) {

  @Test
  fun multipartBodyPart() {
    val requestBody: RequestBody = "".toRequestBody(null)
    var part: MultipartBody.Part = MultipartBody.Part.create(null, requestBody)
    part = MultipartBody.Part.create(headersOf(), requestBody)
    part = MultipartBody.Part.create(requestBody)
    part = MultipartBody.Part.createFormData("", "")
    part = MultipartBody.Part.createFormData("", "", requestBody)

	public static synthetic fun create$default (Lokhttp3/RequestBody$Companion;Ljava/lang/String;Lokhttp3/MediaType;ILjava/lang/Object;)Lokhttp3/RequestBody;
	public static synthetic fun create$default (Lokhttp3/RequestBody$Companion;Lokhttp3/MediaType;[BIIILjava/lang/Object;)Lokhttp3/RequestBody;
	public static synthetic fun create$default (Lokhttp3/RequestBody$Companion;Lokio/ByteString;Lokhttp3/MediaType;ILjava/lang/Object;)Lokhttp3/RequestBody;

        }
      }

    val file = File("docs/images/logo-square.png")
    val requestBody: RequestBody = file.asRequestBody(MEDIA_TYPE_PNG)

    val request =
      Request
        .Builder()
        .header("Authorization", "Client-ID $IMGUR_CLIENT_ID")
        .url("https://api.imgur.com/3/image")
        .post(ProgressRequestBody(requestBody, progressListener))
        .build()