public static boolean checkUrl(String url){
        try {
            HttpURLConnection con = 
                (HttpURLConnection)new URL(url).openConnection();
            int respCode = con.getResponseCode();
            return respCode==404 ? false : true;
            //return respCode!=200 ? false : true;
        } catch (Exception e) {
            e.printStackTrace();
            return false;
        }
    }