java.lang.IndexOutOfBoundsException：索引：0，大小：0错误

Question

启动服务器时，我不断收到此错误：

  

java.lang.IndexOutOfBoundsException：索引：0，大小：0。

这是引起它的插件的代码。我已经看完了，没有发现任何错误

public class C06 extends ListenerAdapter implements CommandExecutor, Listener {

    public Main plugin;
    public HashMap<UUID,String> uuidCodeMap;
    public HashMap<UUID,String> uuidIdMap;
    public List<UUID> verifiedmembers;
    public Guild guild;
    JDA jda;

    public C06(Main main) {
        this.plugin = main;
        startBot();
        uuidCodeMap = new HashMap<>();
        uuidIdMap = new HashMap<>();
        verifiedmembers = new ArrayList<>();
        jda.addEventListener(this);
        plugin.getServer().getPluginManager().registerEvents(this,plugin);
        plugin.getCommand("verify").setExecutor(this);
        Bukkit.getScheduler().runTaskLater(plugin,()->guild = jda.getGuilds().get(0),100L);
    }

    private void startBot() {
        try {
            jda = new JDABuilder(AccountType.BOT).setToken(plugin.getConfig().getString("bot-token")).build();
        } catch (LoginException e) {
            e.printStackTrace();
        }
    }

    @Override
    public void onGuildMessageReceived(GuildMessageReceivedEvent event) {
        if(event.getAuthor().isBot() || event.getAuthor().isFake() || event.isWebhookMessage())return;
        String[] args = event.getMessage().getContentRaw().split(" "); //!link args args args
        if(args[0].equalsIgnoreCase(".verify")){ 
            if(event.getMember().getRoles().stream().filter(role -> role.getName().equals("Verified")).findAny().orElse(null) != null){
                event.getChannel().sendMessage(":x: **|** Error! "+event.getAuthor().getAsMention()+", you are already verified!").queue();
                return;
            }
            if(uuidIdMap.values().contains(event.getAuthor().getId())){
                event.getChannel().sendMessage(":x: **|** Error! "+event.getAuthor().getAsMention()+", you already have a code generated!").queue();
                return;
            }
            String randomcode = new Random().nextInt(800000)+200000+"AA"; //6581446AA
            uuidCodeMap.put(target.getUniqueId(),randomcode);
            uuidIdMap.put(target.getUniqueId(),event.getAuthor().getId());
            event.getAuthor().openPrivateChannel().complete().sendMessage("Hey! Your verification has been generated!\n" +
                    "Use this command in game: ``/verify "+randomcode+"``").queue();
            event.getChannel().sendMessage(":white_check_mark: Please Check Your DM's For The Verification Code!");
        }
    }

    @EventHandler
    public void onJoin(PlayerJoinEvent e){
        if(plugin.playerData.contains("Data."+e.getPlayer().getUniqueId().toString())){
            verifiedmembers.add(e.getPlayer().getUniqueId());
        }
    }

    @EventHandler //This is to remove the player from all lists and maps when he leaves the server.
    public void onQuit(PlayerQuitEvent e){
        verifiedmembers.remove(e.getPlayer().getUniqueId());
        uuidCodeMap.remove(e.getPlayer().getUniqueId());
        uuidIdMap.remove(e.getPlayer().getUniqueId());
    }

    @Override
    public boolean onCommand(CommandSender sender, Command cmd, String label, String[] args) { //  /verify randomcodeAA
        if(!(sender instanceof Player)){
            sender.sendMessage("§cOnly players can execute this command!");
            return true;
        }
        Player player = (Player) sender;
        if(plugin.playerData.contains("Data."+player.getUniqueId().toString())){
            player.sendMessage("§cSorry! You are already verified!");
            return true;

        String actualcode = uuidCodeMap.get(player.getUniqueId());
        if(!actualcode.equals(args[0])){
            player.sendMessage("§cCode is not valid! Check again!");
            return true;
        }
        String discordid = uuidIdMap.get(player.getUniqueId());
        Member target = guild.getMemberById(discordid);
        if(target == null){
            uuidCodeMap.remove(player.getUniqueId());
            uuidIdMap.remove(player.getUniqueId());
            player.sendMessage("§cError! It seems that you left our Discord server!");
            return true;
        }
        plugin.playerData.set("Data."+player.getUniqueId().toString(),discordid);
        try {
            plugin.playerData.save(plugin.data);
        } catch (IOException e) {
            e.printStackTrace();
        }
        uuidCodeMap.remove(player.getUniqueId());
        uuidIdMap.remove(player.getUniqueId());
        verifiedmembers.add(player.getUniqueId());
        Role verifiedrole = guild.getRolesByName("Verified",false).get(0);
        guild.getController().addSingleRoleToMember(target,verifiedrole).queue();
        target.getUser().openPrivateChannel().complete().sendMessage(":white_check_mark: **|** Verification successful, you have linked your account with Mc account: "+player.getName()).queue();
        player.sendMessage("§aYou have been verified correctly! You linked your account with member: "+target.getUser().getName()+"#"+target.getUser().getDiscriminator());
        return true;
    }  

我希望您能为我提供帮助，因为这是非常重要的事情！