Get unique integer value from string

Question

I have different unique strings in the same format. The string looks like this axf25!j&809>-11~dc and I want to get unique integer value from this string.

Answer 1

You could just use String.hashCode() (e.g. mystring.hashCode()) to give you a degree of uniqueness but you must ensure you can handle collisions.

Answer 2

You can't guarantee unique integer values from different strings since there are more possible string representations than integers. You can use some well known/defined hashing algorithm to minimize the chance of a collision. You should look at MD5 or SHA.

The java class MessageDigest should be of some use.

Answer 3

You cannot generate entirely unique ints from sufficiently long strings because there are more 10-character strings than 32-bit integers.

As far as non-unique solutions go, you can use the standard hashCode function, its implementation in Java is reasonably good. For more complex stuff you may consider computing cryptographic hash (SHA-2, MD5, etc.)

Answer 4

You can try with code:

import java.math.BigInteger;

public static BigInteger stringToBigInteger(String text) {
    BigInteger bigInt = new BigInteger(text.getBytes());
    return bigInt;
}

thanks.

Answer 5

Treat the strings as a base 0x110000 representation of some integer (you can get away with a smaller base if you know the range of characters is limited). Convert to a BigInteger.