OkHTTP error cannot access ByteString
<p>I am using OkHttp library to multipart data and everything is good i don't have any error but when i compile the program then it gives me error</p>

<blockquote>
  <p>Error:(172, 40) error: cannot access ByteString
  class file for okio.ByteString not found</p>
</blockquote>

<p>The error occurs here <code>RequestBody.create(MEDIA_TYPE_JPG, new File(data.getFileParam())))</code></p>

<blockquote>
  <p>Here is the whole code of method that implements multipart request</p>
</blockquote>

<pre><code>public static String makeRequest(RequestConstructor data, String a, String b) {
    final MediaType MEDIA_TYPE_JPG = MediaType.parse("image/jpg");
    try {
        OkHttpClient client = new OkHttpClient();

        Log.d("test",data.getFileParam());

        RequestBody requestBody = new MultipartBody.Builder()
                .setType(MultipartBody.FORM)
                .addFormDataPart("bunting", data.getParam("bunting"))
                .addFormDataPart("dangler", data.getParam("dangler"))
                .addFormDataPart("poster", data.getParam("poster"))
                .addFormDataPart("tearPad", data.getParam("tearPad"))
                .addFormDataPart("leafLet", data.getParam("leafLet"))
                .addFormDataPart("outlet_category", "")
                .addFormDataPart("dealerName", data.getParam("dealerName"))
                .addFormDataPart("brouchers", data.getParam("brouchers"))
                .addFormDataPart("wobblers", data.getParam("wobblers"))
                .addFormDataPart("tentCard", data.getParam("tentCard"))
                .addFormDataPart("others", data.getParam("others"))
                .addFormDataPart("photo", "1.jpg",
                        RequestBody.create(MEDIA_TYPE_JPG, new File(data.getFileParam())))
                .build();

        Request request = new Request.Builder()
                .url(data.getUrl())
                .post(requestBody)
                .build();

        Response response = client.newCall(request).execute();
        if (!response.isSuccessful()) throw new IOException("Unexpected code " + response);
        Log.d("From OkHTTP Response", response.toString());
        System.out.println(response.body().string());
    } catch (IOException e) {
        e.printStackTrace();
    }

    return null;
}
</code></pre>

<p>I don't have any import for okio class so i tried to add manully fun android studio show syntax error <code>cannot resolve symbol okio</code></p>