KnightzAPI Downloader

Downloader.java

public class Downloader {

    public static void downloadKnightzAPI(Plugin yourPlugin) {
        try {
            URL gitHubURL = new URL("https://api.github.com/repos/knightzmc/knightzapi/releases/latest");
            HttpURLConnection connection = (HttpURLConnection) gitHubURL.openConnection();
            connection.setRequestMethod("GET");
            if (connection.getResponseCode() == 200) {
                BufferedReader in = new BufferedReader(new InputStreamReader(connection.getInputStream()));
                String content = in.lines().collect(Collectors.joining());
                in.close();
                connection.disconnect();
                JsonParser parser = new JsonParser();
                JsonElement parsed = parser.parse(content);
                String releaseURL = parsed.getAsJsonObject().get("url").getAsString() + "/knightzapi.jar";
                URL release = new URL(releaseURL);
                ReadableByteChannel releaseByteChannel = Channels.newChannel(release.openStream());
                File knightzAPIFile = new File(yourPlugin.getDataFolder(), "knightzapi.jar");
                //If it exists but has not been loaded assume it is corrupt
                if (knightzAPIFile.exists()) {
                    knightzAPIFile.delete();
                }
                FileOutputStream outputKA = new FileOutputStream(knightzAPIFile);
                FileChannel channel = outputKA.getChannel();
                channel.transferFrom(releaseByteChannel, 0, Long.MAX_VALUE);
                Logger logger = yourPlugin.getLogger();
                logger.info("----------------------------------------------------------------");
                logger.info("KnightzAPI successfully downloaded! You should restart your server to enable the plugin.");
                logger.info("/reload or plugin managers are not supported in this context.");
                logger.info(yourPlugin.getName() + " will not be enabled until the server is reloaded");
                logger.info("----------------------------------------------------------------");
            } else {
                throw new RuntimeException(yourPlugin.getName() + " failed to download KnightzAPI! GitHub returned code " + connection.getResponseCode());
            }
        } catch (IOException e) {
            throw new RuntimeException(yourPlugin.getName() + " failed to download KnightzAPI! Reason: " + e.getMessage());
        }
    }
}

//call this when you want to get the API
if (getServer().getPluginManager().getPlugin("KnightzAPI") == null) {
			getLogger().warning("KnightzAPI not found - downloading now!");
			Downloader.downloadKnightzAPI(this);
			getPluginLoader().disablePlugin(this);
}