Download a media from a message

This snippet will get the most recent conversation and download the media attached with the message (if any).
The media can be a file, a photo, a sticker, a gif, etc.

// This is a synchronous client, that will block until the response arrive (or until timeout)
TelegramClient client = Kotlogram.getDefaultClient(application, new ApiStorage());

// You can start making requests
try {
    TLAbsDialogs tlAbsDialogs = client.messagesGetDialogs(0, 0, new TLInputPeerEmpty(), 1);
    TLAbsInputPeer inputPeer = getInputPeer(tlAbsDialogs);

    // Get most recent message
    TLAbsMessages tlAbsMessages = client.messagesGetHistory(inputPeer, 0, 0, 0, 1, 0, 0);
    TLAbsMessage tlAbsMessage = tlAbsMessages.getMessages().get(0);

    if (tlAbsMessage instanceof TLMessage && ((TLMessage) tlAbsMessage).getMedia() != null) {
        TLAbsMessageMedia media = ((TLMessage) tlAbsMessage).getMedia();

        // Magic utils method from api module
        MediaInput mediaInput = TLMediaUtilsKt.getAbsMediaInput(media);

        if (mediaInput != null) {
            String filename;
            if (media instanceof TLMessageMediaPhoto || media instanceof TLMessageMediaWebPage) {
                filename = "photo.jpg";
            } else {
                // Retrieve real name
                TLDocument tlDocument = ((TLMessageMediaDocument) media).getDocument().getAsDocument();
                filename = ((TLDocumentAttributeFilename) tlDocument.getAttributes().stream()
                                                                    .filter(attr -> attr instanceof TLDocumentAttributeFilename)
                                                                    .findFirst().get()).getFileName();
            }

            FileOutputStream fos = new FileOutputStream(new File(ROOT_DIR, filename));
            client.downloadSync(mediaInput.getInputFileLocation(), mediaInput.getSize(), fos);
            // downloadSync closes the stream automatically
        } else {
            System.err.println("MessageMedia type not supported" + media.getClass().getSimpleName());
        }
    } else {
        System.err.println("Latest message has no media attached");
    }
} catch (RpcErrorException | IOException e) {
    e.printStackTrace();
} finally {
    client.close(); // Important, do not forget this, or your process won't finish
}

This tl-schema of the API can sometime complicates things a lot with a lot of abstraction, moreover when dealing with them in Java.