public static void saveChannels() {
        File channelFolder = new File(System.getProperty("user.dir") + "\\channels");
        File channelList = new File(channelFolder.getAbsolutePath() + "\\channels.txt");
        if(categories.isEmpty()) {
            channelList.delete();
        }
        try {
            FileWriter writer = new FileWriter(channelList, false);
            for(Map.Entry<String, Category> entry : categories.entrySet()) {
                for(YTChannel channel : entry.getValue().getChannels())
                    writer.write(entry.getValue() + "&" + channel.channelName + "&" + channel.lastChecked.saveFormat() + "\n");
            }
            writer.close();
        } catch (IOException e1) {
            e1.printStackTrace();
        }
    }