Request Body for input stream

requesBody.md

   public class InputStreamRequestBody extends RequestBody {
   private final MediaType contentType;
   private final ContentResolver contentResolver;
   private final Uri uri;

   public InputStreamRequestBody(MediaType contentType, ContentResolver contentResolver, Uri uri) {
       if (uri == null) throw new NullPointerException("uri == null");
       this.contentType = contentType;
       this.contentResolver = contentResolver;
       this.uri = uri;
   }

   @Nullable
   @Override
   public MediaType contentType() {
       return contentType;
   }

   @Override
   public long contentLength() throws IOException {
       return -1;
   }

@Override
public void writeTo(@NonNull BufferedSink sink) throws IOException {
    sink.writeAll(Okio.source(contentResolver.openInputStream(uri)));
}
}