Method IsDigit

builder/index/src/main/java/InvertedIndex/plugin/Util.java:77–84

(String str)

        test_str("111");
     * */
    public static boolean IsDigit(String str) {
        for (int i = str.length(); --i >= 0; ) {
            if (!Character.isDigit(str.charAt(i))) {
                return false;
            }
        }
        return true;
    }

    public static boolean IsHexadecimal(String str) {
        Pattern p = Pattern.compile("^0x[a-fA-F0-9]+");