public static boolean isAvaible(URLConnection connection) {
		
		if(connection instanceof JarURLConnection)
			return true;
		
		if(connection instanceof HttpURLConnection)
			try {
				return ((HttpURLConnection) connection).getResponseCode() == HttpURLConnection.HTTP_OK;
			} catch (IOException e) {
				e.printStackTrace();
				return false;
			}
		
		if(connection instanceof FileURLConnection)
			return true;
		
		return false;
	}