How to escape/encode supplementary characters in resource names

Hello everybody,

this is my first post in the forum so please forgive me if I may have posted this in the wrong subforum

Now to my question:

We have built our own custom authentication plugin, that allows users from our systems to login into openfire.

The plugin creates rooms which can only be joined by users if they are in a certain group and forces them to user their default nickname.

This works rather nice except for when the user has emojis or other supplementary characters in their nickname.

In those cases i get a malformed jid error.

Example:

the nickname above contains the name symbol U+1F600 "grinning face".

I'am using the smack client to connect to our openfire server:

  connection.connect();  connection.login("501-32", "somepassword");  MultiUserChat room = new MultiUserChat(connection, "6536-32@mydomain.localhost.local");  // server responds malformed JID  room.join("emoji  Username");  room.sendMessage("cri' cri' cri'");
room.leave();

I double checked with wireshark and it seems that the format of the JID is correct

6536-32@mydomain.localhost.local/emoji\xf0\x9f\x98\x84Username

Do I have to escape supplementary characters? Am I doing something wrong?

Edit:

Unfortunately the forum is "eating" the emoji >.<   the 2 spaces are the emoji symbol