public static String hexToString(String hex) {
        StringBuilder output = new StringBuilder();
        for (int i = 0; i < hex.length(); i += 2) {
            String str = hex.substring(i, i + 2);
            char ch = (char) Integer.parseInt(str, 16);
            output.append(ch);
        }
        return output.toString();
    }
UnHexFunction  -> unhex(str)
description:
Return null if 'str' is null;
Return the result of interpreting each pair of characters in the argument as the character corresponding
       to its hexadecimal number.
inlong-sdk/transform-sdk/src/main/java/org/apache/inlong/sdk/transform/process/function/string/UnHexFunction.java