Create a RequestBody from a HashMap of paramaters directly?

Question

I've been googling for a while now and cannot find the solution to my question that is clean, or not a shady/hacky way of doing things.

I also looked at okhttp's wiki where it clearly shows how to make a POST request with paramaters, albeit it is constructed using the class FormEncodingBuilder which does not allow the use of HashMap's in it's creation as it is created as a chain of paramaters, like so (taken from okhhtp's wiki):

  private final OkHttpClient client = new OkHttpClient();

  public void run() throws Exception {
    RequestBody formBody = new FormEncodingBuilder()
      .add("search", "Jurassic Park")
      .build();
    Request request = new Request.Builder()
      .url("https://en.wikipedia.org/w/index.php")
      .post(formBody)
      .build();

    Response response = client.newCall(request).execute();
    if (!response.isSuccessful()) throw new IOException("Unexpected code " + response);

    System.out.println(response.body().string());
  }

Here we can see how the paramaters are added to the RequestBody. But it does not answer how I add a HashMap full of paramaters directly, not one by one.

---

The solutions I have so far are simply looping through each EntrySet in the HashMap and adding it to the RequestBody like so (taken from here):

 public static final MediaType MEDIA_TYPE_MARKDOWN = MediaType.parse("text/x-markdown; charset=utf-8");
 ...
 parameters = "param1=text&param2=" + param2  // for example !
    request = new Request.Builder()
            .url(url + path)
            .post(RequestBody.create(MEDIA_TYPE_MARKDOWN, parameters))
            .build();

Though this does solve my problem, I was wondering if there is a way to directly make a RequestBody via a HashMap in okhttp or do I have to use another framework?

This is the code I used in the meanwhile:

String param = "";
for (Map.Entry < String, Object > entry: params.entrySet()) {
  param += entry.getKey() + "=" + entry.getValue() + "&";
}
param.substring(0, param.length() - 1);
Request request = new Request.Builder()
  .url(endPoint)
  .post(RequestBody.create(MEDIA_TYPE_MARKDOWN, param))
  .build();