Absolute value java

Question

I am trying to create a directory with the name of the absolute value of the hexadecimal version of a hashed url, using the built-in hash() method of the String class. Now it is possible for hash() to produce a negative result, and a directory name starting with a minus sign is somewhat hard to handle which is why I need the absolute value of this. However, I cannot figure out how to get the absolute value of the hexadecimal version of the hashed url string.

Answer 1

The hex value never has a negative sign! It is just the hexadecimal representation of the two's compliment bit pattern of the value.

System.out.println(Integer.toHexString(-1)); // ffffffff
System.out.println(Integer.toHexString(Integer.MIN_VALUE)); // 80000000

Just like your mother always told you: "You're perfect just the way you are":

String dirname = Integer.toHexString(dirname.hashCode()); // never has minus sign

Answer 2

Coerce it to a long, mask out the top 32 bits, then convert that to a string.

 long longHash = intHash;
 long nonNegativeLongHash = longHash & ((1L << 32) - 1);
 String unsignedHex = Long.toHexString(nonNegativeLongHash);