static String getSupposablyMime(String url) {
        MimeTypeMap mimes = MimeTypeMap.getSingleton();
        String extension = MimeTypeMap.getFileExtensionFromUrl(url);
        return TextUtils.isEmpty(extension) ? null : mimes.getMimeTypeFromExtension(extension);
    }
Just simple utils.

@author Alexey Danilov (danikula@gmail.com).
dkplayer-videocache/src/main/java/com/danikula/videocache/ProxyCacheUtils.java