Format "raw" string to Java UUID in PHP

Question

Is there a more effective, simplified means of converting a "formatted" Java UUID - without dashes - to a Java compatible format - with dashes - in PHP, and ultimately: How would I do it?

I have code that already performs this action, but it seems unprofessional and I feel that it could probably be done more effectively.

[... PHP code ...]
$uuido = $json['id'];

$uuidx = array();
$uuidx[0] = substr( $uuido, 0, 8 );
$uuidx[1] = substr( $uuido, 8, 4 );
$uuidx[2] = substr( $uuido, 12, 4);
$uuidx[3] = substr( $uuido, 16, 4);
$uuidx[4] = substr( $uuido, 20, 12);

$uuid = implode( "-", $uuidx );
[... PHP code ...]

Input:  f9e113324bd449809b98b0925eac3141
Output: f9e11332-4bd4-4980-9b98-b0925eac3141

The data from $json['id'] is called from the following Mojang Profile API using the file_get_contents( $url ) function combined with a json_decode( $file ), which could alternatively be done through cURL - but since it would eventually be requesting anything up to 2048 profiles at once, I figured it would become slow.

I do have my code in use, and public, through the following ProjectRogue Server Ping API, which usually contains a list of online players.

Note: There are several questions related to this, but none apply to PHP as far as I am aware. I have looked.

I mention Java UUID as the parsed output should effectively translate to a Player UUID for use in a Java-Based plugin for Spigot or Craftbukkit after 1.7.X.

You haven't specified what language you're trying to achieve the formatting of UUID's in... You've mentioned the word Java while only supplying PHP code and queries. Can you be a little more clear about what you're trying to do? — px06, Sep 15 '16 at 13:40

score 2 · Answer 1 · answered Sep 15 '16 at 13:43

UUID is not a special java format. It is the Universal Unique Identifier.

A universally unique identifier (UUID) is an identifier standard used in software construction. A UUID is simply a 128-bit value.

What happen is that the conversion from the 128 bit value to a human readable version of the same value converting it to a string follow generally some conventions.

Basically the number is converted to the better human readable hexadecimal format with some hyphen to separate block of bits.

From a performance perspective you can use the several times the substr_replace function, instead of creating an array of strings using substr and applying implode to it.

Review Question: _[...] I mention Java UUID as the parsed output should effectively translate to a Player UUID for use in a Java-Based plugin for Spigot or Craftbukkit after 1.7.X._ — LeoV117, Sep 15 '16 at 13:46

score 2 · Accepted Answer · edited May 23 '17 at 12:08

Your question doesn't make much sense but assuming you want to read the UUID in the correct format in Java you can do something like this:

import java.util.UUID;
class A
{
    public static void main(String[] args){


        String input = "f9e113324bd449809b98b0925eac3141";                         
        String uuid_parse = input.replaceAll(                                            
                        "(\\w{8})(\\w{4})(\\w{4})(\\w{4})(\\w{12})",                            
                        "$1-$2-$3-$4-$5");                                                      

        UUID uuid = UUID.fromString(uuid_parse);
        System.out.println(uuid);
    }
}

Borrowed from maerics, see here: https://stackoverflow.com/a/18987428/4195825

Or in PHP you can do something like:

<?php 
    $UUID = "f9e113324bd449809b98b0925eac3141";
    $UUID = substr($UUID, 0, 8) . '-' . substr($UUID, 8, 4) . '-' . substr($UUID, 12, 4) . '-' . substr($UUID, 16, 4)  . '-' . substr($UUID, 20);
    echo $UUID;
?>

Borrowed from fico7489: https://stackoverflow.com/a/33484855/4195825

And then you can send that to Java where you can create a UUID object using fromtString().

Your second answer directed me to an [effective solution](http://stackoverflow.com/a/33484916/3257339) through the following means: `$uuid = preg_replace( "/(\w{8})(\w{4})(\w{4})(\w{4})(\w{12})/i", "$1-$2-$3-$4-$5", $json[ 'id' ] );` — LeoV117, Sep 15 '16 at 14:08
@LeoV117 while I think that regex is nice to use, in some cases I tend to avoid it when I can see a solution with native features like `substr()` however, in this case regex **may** have an advantage of being faster. — px06, Sep 15 '16 at 14:10

Format "raw" string to Java UUID in PHP

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