Converting from hex to int in java

Question

I am getting an error because of the following line of code:

int x = color(Integer.parseInt("ffffffde",16));

I think it might be because it is a minus value

Any ideas why or how or how to fix it?

EDIT:

Sorry, didn't include the actual error. here it is:

Exception in thread "Animation Thread" java.lang.NumberFormatException: For input string: "ffffffde" at java.lang.NumberFormatException.forInputString(Unknown Source) at java.lang.Integer.parseInt(Unknown Source)

EDIT 2:

The value ("ffffffde") is being created by the following code:

Integer.toHexString(int_val);

EDIT 3: Turns out it is a known bug (http://bugs.sun.com/bugdatabase/view_bug.do?bug_id=4215269) Although you can convert integers to hex strings, you cannot convert them back if they are negative numbers!!

An error? Wonder what that might be. – Thorbjørn Ravn Andersen May 21 '12 at 07:51 — Thorbjørn Ravn Andersen, May 21 '12 at 07:51

juergen d · Accepted Answer · 2012-12-27T20:43:11.900

12

ffffffde is bigger than integer max value

Java int is 32 bit signed type ranges from –2,147,483,648 to 2,147,483,647.

ffffffde = 4,294,967,262

Edit

You used Integer.toHexString(int_val) to turn a int into a hex string. From the doc of that method:

Returns a string representation of the integer argument as an unsigned integer in base 16.

But int is a signed type.

USE

int value = new BigInteger("ffffffde", 16).intValue();

to get it back as a negative value.

edited Dec 27 '12 at 20:43

answered May 21 '12 at 07:52

juergen d

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Right `4294967262` is out of `int` range – jmj May 21 '12 at 07:54
But the value is being created by using "Integer.toHexString(int_val)" – user1270235 May 21 '12 at 08:01
3

`+1` good answer, by the way I also knew the person [you are talking here](http://meta.stackexchange.com/questions/176318/what-is-considered-incorrect-tagging). – John Woo Apr 24 '13 at 13:31

score 5 · Answer 2 · answered May 21 '12 at 07:56

If you are getting error like this,

Exception in thread "main" java.lang.NumberFormatException: For input string: "ffffffde"
    at java.lang.NumberFormatException.forInputString(NumberFormatException.java:48)
    at java.lang.Integer.parseInt(Integer.java:461)
    at com.TestStatic.main(TestStatic.java:22)

Then there is problem with value you are passing that is ffffffde . This is not a valid hex value for parsing to int.

Please try this

int x = Integer.parseInt("ffffde",16);
        System.out.println(x);

It should work.

For hex values more than that you have to pars to Long

Long x = Long.parseLong("ffffffde",16);
        System.out.println(x);

And this also should work

Converting from hex to int in java

2 Answers2

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