public class ClassName {

        /* code */

        // Pattern for recognizing a URL, based off RFC 3986
        private static final Pattern urlPattern = Pattern.compile(
                "(?:^|[\\W])((ht|f)tp(s?):\\/\\/|www\\.)"
                + "(([\\w\\-]+\\.){1,}?([\\w\\-.~]+\\/?)*"
                + "[\\p{Alnum}.,%_=?&#\\-+()\\[\\]\\*$~@!:/{};' ]*)",
                Pattern.CASE_INSENSITIVE | Pattern.MULTILINE | Pattern.DOTALL);


        // function to check if qr contains url
        public boolean isURL(String str){

                if (urlPattern.matcher(str).matches()
                        return true;
                else
                        return false;
       }


       /* code */
}