How to get file size using retrofit 2 . I tried by return -1?

Question

I want to build App to download file with progress-bar and I tried to get file size from server. while using retrofit 2 library but failed to get the total-file size. and return -1, i tested its work on build:gradle:3.0.1 but not in build:gradle:3.5.3

here my code

    ApiService apiService = RetroClient.getApiService();
    Call<ResponseBody> call = apiService.downloadFile("fsharpapps/fonts/customFont.ttf");
    call.enqueue(new Callback<ResponseBody>() {
        @Override
        public void onResponse(Call<ResponseBody> call, Response<ResponseBody> response) {
            if (response.isSuccessful()) {
                    if (response.body() != null) {
                        AppUtil.mToast(DownloadService.this, "Downloading...");
                        boolean isDownload = writeResponseBodyToDisk(response.body());
                        if (isDownload) 
                            AppUtil.mToast(DownloadService.this, "file size" + response.body().contentLength());
                      }}
        }
        @Override
        public void onFailure(Call<ResponseBody> call, Throwable t) {
        }
    });
// output is file size -1

but when I check header file it working good.

here is HTTP Status for: "http://mywebsite.com/fsharpapps/fonts/customFont.ttf"

    HTTP/1.1 200 OK
    Date: Tue, 31 Dec 2019 19:03:16 GMT
    Server: Apache
    Upgrade: h2,h2c
    Connection: Upgrade, close
    Last-Modified: Sat, 21 Oct 2017 08:55:53 GMT
    Accept-Ranges: bytes
    Content-Length: 13857268
    Vary: Accept-Encoding,User-Agent
    Content-Type: font/ttf

Answer 1

Use header in your interface

public interface RetrofitInterface {
    @Headers({"Accept-Encoding: *","Content-Type: font/ttf"})
    @Streaming
    @GET("yourfile.ttf")
    Call<ResponseBody> downloadFile();
}