Get UUID from name for offline player

[DaComputerNerd]

I am having difficulty with my mod in getting the UUID of an offline player from their name. How can I do this? I am using forge version 1.12.2 - 14.23.1.2555.

[xwerswoodx]

I don't know if it's possible to get from UUID from offline player (I haven't tried it before) but you can save player uuid to configuration file when he logged in server first time, and you can check his nickname from configuration file. If I remember correct, playerLoginEvent or LoggedIn event could be suitable for this.

[Differentiation]

11 hours ago, diesieben07 said:

An offline player by definition has no real UUID. There is code to create some fake UUID based on the name, but this is terrible, since the UUID will then change once they are online again (this will make the player's pets forget their owner, etc.).

 

You should not play offline

Maybe the OP is talking about player's that are not present on the world or players that are not really logged on?

Edited January 17, 2018 by Differentiation

[DaComputerNerd]

I mean the UUID that is used to keep stuff like inventory when you change your username and track previous names.

 

By  offline I mean they are not on the server. Not that they pirated the game or something.

 

I figured it out. Make an HTTP GET request to https://api.mojang.com/users/profiles/minecraft/username?at=time, but replacing the username and time with the actual username and time. the ?at= portion is not required. It returns the UUID and the name they had at the given time, in JSON format. You can go there with your own name to check this. 

Edited January 28, 2018 by DaComputerNerd

[DaComputerNerd]

On 1/28/2018 at 7:35 AM, diesieben07 said:

You should use PlayerProfileCache::getGameProfileForUsername instead, which will only make a request to the API if needed and cache results.

Good to know. Finding documentation was difficult.

My mod stores the data during runtime anyways, and makes the request when the command is run and the player is not found in the hashmap.