Convert hex string to int

I am trying to convert a string that is 8 characters long of hex code into an integer so that I can do int comparison instead of string comparisons over a lot of different values. I know this is fairly trivial in C++ but I need to do it in Java. The test case I need to satisfy is essentially to Convert "AA0F245C" to int and then back to that string so that I know it is converting right. I have tried the following: ``` int decode = Integer.decode("0xAA0F245C"); // NumberFormatException int decode2 = Integer.decode("AA0F245C"); //NumberFormatException int parseInt = Integer.parseInt("AA0F245C", 16); //NumberFormatException int valueOf = Integer.valueOf("AA0F245C", 16); //NumberFormatException ``` I have also tried doing it two characters at a time and multiplying the results, which the conversion works but the number is not right. ``` int id = 0; for (int h = 0; h < hex.length(); h= h+2) { String sub = hex.subSequence(h, h+2).toString(); if (id == 0) id = Integer.valueOf(sub, 16); else id *= Integer.valueOf(sub, 16); } //ID = 8445600 which = 80DEA0 if I convert it back. ``` I can not use third party libraries just so you know, so this has to be done in Java standard libraries. Thank you for your help in advance.