Creating a UUID from a string with no dashes

Question

How would I create a java.util.UUID from a string with no dashes?

\"5231b533ba17478798a3f2df37de2aD7\" => #uuid \"5231b533-ba17-4787-98a3-f2df37de2aD7\"
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Answer 1

Here is an example that is faster because it doesn't use regexp.

public class Example1 {
    /**
     * Get a UUID with hyphens from 32 char hexadecimal.
     * 
     * @param string a hexadecimal string
     * @return a UUID string
     */
    public static String toUuidString(String string) {

        if (string == null || string.length() != 32) {
            throw new IllegalArgumentException("invalid input string!");
        }

        char[] input = string.toCharArray();
        char[] output = new char[36];

        System.arraycopy(input, 0, output, 0, 8);
        System.arraycopy(input, 8, output, 9, 4);
        System.arraycopy(input, 12, output, 14, 4);
        System.arraycopy(input, 16, output, 19, 4);
        System.arraycopy(input, 20, output, 24, 12);

        output[8] = '-';
        output[13] = '-';
        output[18] = '-';
        output[23] = '-';

        return new String(output);
    }

    public static void main(String[] args) {
        String example = "daa70a7ffa904841bf9a81a67bdfdb45";
        String canonical = toUuidString(example);
        UUID uuid = UUID.fromString(canonical);
    }
}