How to suppress Charset being automatically added to Content-Type in okhttp

Question

Consider the following code:

    OkHttpClient client = new OkHttpClient();

    MediaType mediaType = MediaType.parse(\"text/plain; charset=utf-8\"); // [A]
         


        

Answer 1

When you create requestbody, just set the content typy as "null", and add header manual, like this:

    OkHttpClient client = new OkHttpClient();

    RequestBody body = RequestBody.create('your media string', null);
    String[] aclHeader = "x-goog-acl:public-read".split(":");

    Request request = new Request.Builder()
            .addHeader("Content-Type", "text/plain") // [B]
            .addHeader(aclHeader[0], aclHeader[1])
            .url(url)
            .put(body)
            .build();

    Response response = client.newCall(request).execute();

Beacuse when I read okhttp source code, in RequestBody.kt, I find following code:

   /**
     * 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 {
      var charset: Charset = UTF_8
      var finalContentType: MediaType? = contentType
      if (contentType != null) {
        val resolvedCharset = contentType.charset()
        if (resolvedCharset == null) {
          charset = UTF_8
          finalContentType = "$contentType; charset=utf-8".toMediaTypeOrNull()
        } else {
          charset = resolvedCharset
        }
      }
      val bytes = toByteArray(charset)
      return bytes.toRequestBody(finalContentType, 0, bytes.size)
    }

Answer 2

I found the solution:

The following line is the culprit:

RequestBody body = RequestBody.create(mediaType, media);

create has 3 signatures for media:

• String
• byte[]
• File

When I pass a String, it disregards the supplied mediaType and adds the charset to it. Even for image/jpeg it would send

image/jpeg; charset=utf-8

to the server.

Using byte[] or File suppresses that behavior.

I hope this helps you!

[Stupid me - for simplicity I gave it a String during testing, as I didn't care about the body ;-( ]