How to convert big hex String to int?

Question

Ok I have this hex string "efe4b4f355de4cbc" which I want to convert to integer. In python I do this:

print int("efe4b4f355de4cbc",16)

and the output I get is 17286140226965490876.

Now when I try to do the same in Java using the following code:

long convertedHex = Long.parseLong("efe4b4f355de4cbc", 16);

All I get is

java.lang.NumberFormatException: Invalid long: "efe4b4f355de4cbc"

But why?

Anyhow then I though I should try a BigInteger so next thing I did was this

long convertedHex = new BigInteger("efe4b4f355de4cbc", 16).longValue();

Now the result I get is -1160603846744060740 but that's not what I want. I want the same result as in python language.

@SotiriosDelimanolis I'm not sure about the Long max capacity. That's why I tried BigInteger next — ThanosFisherman, Oct 23 '15 at 15:33
You tried `BigInteger`, then you used its `longValue` method. What does its `longValue` method do? — Sotirios Delimanolis, Oct 23 '15 at 15:34
String s = "efe4b4f355de4cbc"; BigInteger bi = new BigInteger(s, 16); System.out.println(bi); on my pc gives 17286140226965490876 so you better switch to mine... ;) — Petter Friberg, Oct 23 '15 at 15:34
Also, _I'm not sure about the Long max capacity_: https://docs.oracle.com/javase/tutorial/java/nutsandbolts/datatypes.html — Sotirios Delimanolis, Oct 23 '15 at 15:35
@PetterFriberg That's strange! Actually I'm trying this on an android phone! — ThanosFisherman, Oct 23 '15 at 15:35
Dont convert to Long its to small!, Long.MAX_VALUE = 9223372036854775807 — Petter Friberg, Oct 23 '15 at 15:36
@SotiriosDelimanolis I can't find the duplicate post, can you provide a link? — ThanosFisherman, Oct 23 '15 at 15:37
You cannot cast to long, it won't fit. Your value = 17286140226965490876 Long.maxValue = 9223372036854775807 All you can do is BigInteger bi = new BigInteger(s, 16); System.out.println(bi); — Jkike, Oct 23 '15 at 15:38
Ok seems you guys are right. Converting to .long messes things up. So I think I will do my calculations in BigInteger format until the number becomes small enough to fit in an int or long field. Thank you all! — ThanosFisherman, Oct 23 '15 at 15:43

0 Answers0