有没有AndroidStudio OkHttp上传文件的demo呀？

我现在想做一个上传 文件到服务端的实例，但是，找不到。都是打不开的，打开了，也上传不了。路径，这些先不说，就是打不开上传的窗口呀这些。请朋友们给点能跑通的实例或demo，我去学习学习。
很多都是eclipse的，或一些android，我也看不懂，或者说搞不通呀之类的。谢谢

private void uploadMultiFile() {
final String url = "upload url"
File file = new File("fileDir", "test.jpg");
RequestBody fileBody = RequestBody.create(MediaType.parse("application/octet-stream"), file);
RequestBody requestBody = new MultipartBody.Builder()
.setType(MultipartBody.FORM)
.addFormDataPart("image", "test.jpg", fileBody)
.build();
Request request = new Request.Builder()
.url(url)
.post(requestBody)
.build();

    final okhttp3.OkHttpClient.Builder httpBuilder = new OkHttpClient.Builder();
    OkHttpClient okHttpClient  = httpBuilder
            //设置超时
            .connectTimeout(10, TimeUnit.SECONDS)
            .writeTimeout(15, TimeUnit.SECONDS)
            .build();
    okHttpClient.newCall(request).enqueue(new Callback() {
        @Override
        public void onFailure(Call call, IOException e) {
            Log.e(TAG, "uploadMultiFile() e=" + e);
        }


        @Override
        public void onResponse(Call call, Response response) throws IOException {
            Log.i(TAG, "uploadMultiFile() response=" + response.body().string());
        }
    });
}

看不懂你解释的意思