RolePrefixesSimple.java

import sx.blah.discord.handle.impl.events.guild.channel.message.MessageReceivedEvent;
import sx.blah.discord.handle.obj.IGuild;
import sx.blah.discord.handle.obj.IRole;
import sx.blah.discord.handle.obj.IUser;

import java.util.List;

public class RolePrefixes {

    IRole pvtRank;
    String pvt;

    public void updateEveryone(MessageReceivedEvent event) {

        IGuild guild = event.getGuild();

        List<IUser> users = guild.getUsers();

        for (IUser player : users) {
            if (player.hasRole(pvtRank)) {
                guild.setUserNickname(player, pvt + " " + player.getName());
            }
        }
    }
}