File successfully uploaded by my App , but it did not appear on box file

So here is my code:

public class pCloudUpload {
    File outputFolder = new File("/folder/");
    BoxAPIConnection api ;
    BoxFolder rootFolder ;



    public void prepareUpload() {
         api = new BoxAPIConnection("xxxxxxxxxxxx");
         rootFolder = BoxFolder.getRootFolder(api);
         File[] files = outputFolder.listFiles();
         if (files.length > 0) {
            for (File file : files) {
                uploadFile(file);
            }
        } else {
            Log.i("No_File_to_Upload", "0 files to Upload");
        }
    }

    public void uploadFile(File file) {
        FileInputStream stream = null;
        BoxFolder rootFolder = BoxFolder.getRootFolder(api);
        try {
            stream = new FileInputStream(file);
            rootFolder.uploadFile(stream, file.getName());

            Log.i("File Uploaded", "File Uploaded");
        } catch (Exception ex) {
            System.out.print(ex);
        } finally {
            try {
                if (stream != null) {
                    stream.close();
                }
            } catch (Exception ex) {
                Log.i("Exception in Closing", "Exception caught during closing of stream");
            }
        }
    }

}

On logcat of android studio , I get Log that file is successfully uploaded but when i open my account there are no files at all. See the screenshot below:

Please Help me...